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  Subjects -> COMPUTER SCIENCE (Total: 1985 journals)
    - ANIMATION AND SIMULATION (29 journals)
    - ARTIFICIAL INTELLIGENCE (98 journals)
    - AUTOMATION AND ROBOTICS (98 journals)
    - CLOUD COMPUTING AND NETWORKS (63 journals)
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    - COMPUTER GAMES (16 journals)
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    - COMPUTER SCIENCE (1153 journals)
    - COMPUTER SECURITY (45 journals)
    - DATA BASE MANAGEMENT (13 journals)
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    - INFORMATION SYSTEMS (104 journals)
    - INTERNET (92 journals)
    - SOCIAL WEB (50 journals)
    - SOFTWARE (33 journals)
    - THEORY OF COMPUTING (8 journals)

COMPUTER SCIENCE (1153 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 12)
Abakós     Open Access   (Followers: 3)
Academy of Information and Management Sciences Journal     Full-text available via subscription   (Followers: 67)
ACM Computing Surveys     Hybrid Journal   (Followers: 23)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 8)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 13)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 6)
ACM Transactions on Architecture and Code Optimization (TACO)     Hybrid Journal   (Followers: 9)
ACM Transactions on Autonomous and Adaptive Systems (TAAS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Computation Theory (TOCT)     Hybrid Journal   (Followers: 11)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 12)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 3)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 1)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 20)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 9)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 10)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 8)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 11)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 21)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Ad Hoc Networks     Hybrid Journal   (Followers: 11)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26)
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 8)
Advances in Artificial Intelligence     Open Access   (Followers: 15)
Advances in Artificial Neural Systems     Open Access   (Followers: 4)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15)
Advances in Computer Science : an International Journal     Open Access   (Followers: 13)
Advances in Computing     Open Access   (Followers: 3)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 53)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 25)
Advances in Human-Computer Interaction     Open Access   (Followers: 19)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 37)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access  
AEU - International Journal of Electronics and Communications     Hybrid Journal   (Followers: 8)
African Journal of Information and Communication     Open Access   (Followers: 6)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Air, Soil & Water Research     Open Access   (Followers: 7)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 6)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 10)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 3)
American Journal of Computational Mathematics     Open Access   (Followers: 4)
American Journal of Information Systems     Open Access   (Followers: 6)
American Journal of Sensor Technology     Open Access   (Followers: 2)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 5)
Analysis in Theory and Applications     Hybrid Journal  
Animation Practice, Process & Production     Hybrid Journal   (Followers: 5)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 8)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 6)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Software Engineering     Hybrid Journal   (Followers: 12)
Annual Reviews in Control     Hybrid Journal   (Followers: 6)
Anuario Americanista Europeo     Open Access  
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applied and Computational Harmonic Analysis     Full-text available via subscription   (Followers: 2)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 14)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Clinical Informatics     Hybrid Journal   (Followers: 1)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Computer Systems     Open Access   (Followers: 1)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 32)
Applied Medical Informatics     Open Access   (Followers: 10)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 16)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Architectural Theory Review     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 4)
Archive of Numerical Software     Open Access  
Archives and Museum Informatics     Hybrid Journal   (Followers: 120)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 5)
Asia Pacific Journal on Computational Engineering     Open Access  
Asia-Pacific Journal of Information Technology and Multimedia     Open Access   (Followers: 1)
Asian Journal of Computer Science and Information Technology     Open Access  
Asian Journal of Control     Hybrid Journal  
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
Australian Educational Computing     Open Access  
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 3)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 9)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Basin Research     Hybrid Journal   (Followers: 4)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Bioinformatics     Hybrid Journal   (Followers: 293)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 32)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 45)
British Journal of Educational Technology     Hybrid Journal   (Followers: 119)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 2)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal  
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 14)
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal  
Cell Communication and Signaling     Open Access   (Followers: 1)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access  
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
ChemSusChem     Hybrid Journal   (Followers: 7)
China Communications     Full-text available via subscription   (Followers: 7)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Full-text available via subscription   (Followers: 12)
Circuits and Systems     Open Access   (Followers: 16)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
CLEI Electronic Journal     Open Access  
Clin-Alert     Hybrid Journal   (Followers: 1)
Cluster Computing     Hybrid Journal   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Communication Methods and Measures     Hybrid Journal   (Followers: 11)
Communication Theory     Hybrid Journal   (Followers: 19)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
Communications in Partial Differential Equations     Hybrid Journal   (Followers: 3)
Communications of the ACM     Full-text available via subscription   (Followers: 53)
Communications of the Association for Information Systems     Open Access   (Followers: 18)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access  
Complex Adaptive Systems Modeling     Open Access  
Complex Analysis and Operator Theory     Hybrid Journal   (Followers: 2)
Complexity     Hybrid Journal   (Followers: 6)
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 9)
Computación y Sistemas     Open Access  
Computation     Open Access  
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computational Cognitive Science     Open Access   (Followers: 1)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Condensed Matter     Open Access  
Computational Ecology and Software     Open Access   (Followers: 8)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Geosciences     Hybrid Journal   (Followers: 13)
Computational Linguistics     Open Access   (Followers: 23)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Molecular Bioscience     Open Access   (Followers: 2)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Research     Open Access   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computational Science and Techniques     Open Access  
Computational Statistics     Hybrid Journal   (Followers: 13)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 28)
Computer     Full-text available via subscription   (Followers: 83)
Computer Aided Surgery     Hybrid Journal   (Followers: 3)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 7)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 22)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 10)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 1)
Computer Music Journal     Hybrid Journal   (Followers: 14)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Computer Science - Research and Development     Hybrid Journal   (Followers: 7)
Computer Science and Engineering     Open Access   (Followers: 17)
Computer Science and Information Technology     Open Access   (Followers: 11)
Computer Science Education     Hybrid Journal   (Followers: 12)
Computer Science Journal     Open Access   (Followers: 20)

        1 2 3 4 5 6 | Last

Journal Cover ChemSusChem
  [SJR: 2.649]   [H-I: 88]   [7 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1864-5631 - ISSN (Online) 1864-564X
   Published by John Wiley and Sons Homepage  [1576 journals]
  • Design Rules for Oxygen Evolution Catalysis at Porous Iron Oxide
           Electrodes: Thousand-Fold Current Density Increase
    • Authors: Sandra Haschke; Dmitrii Pankin, Yuri Petrov, Sebastian Bochmann, Alina Manshina, Julien Bachmann
      Abstract: Nanotubular iron(III) oxide electrodes are optimized for catalytic proficiency in the water oxidation reaction at neutral pH. Nanostructured electrodes are prepared from anodic alumina templates coated with Fe2O3 by atomic layer deposition. Scanning helium ion microscopy, X-ray diffraction and Raman spectroscopy characterize the morphology and phase of samples submitted to various treatments. These methods document the contrasting effects of thermal annealing, on the one hand, and of electrochemical treatment, on the other hand. The electrochemical performance of the corresponding electrodes in dark conditions is quantified by steady-state electrolyses and electrochemical impedance spectroscopy. A rough and amorphous Fe2O3 with phosphate incorporation proves to be optimal in the water oxidation reaction. In combination with the ideal pore length L = 17 μm, the maximized catalytic turnover is reached with an effective current density J = 140 μA cm(-2) at 0.49 V applied overpotential η.
      PubDate: 2017-07-26T04:26:19.037639-05:
      DOI: 10.1002/cssc.201701068
       
  • Aquivion PFSA as an Efficient Pickering Interfacial Catalyst for the
           Hydrolysis of Triglycerides
    • Authors: Marc Pera-Titus; Hui Shi, Bing Hong, Flora Fan
      Abstract: Aquivion® Perfluorosulfonic Superacid catalyzed efficiently the solvent-free hydrolysis of glyceryl trilaurate at 100 oC and ambient pressure via the genesis of stable Pickering emulsions.
      PubDate: 2017-07-25T09:26:38.235951-05:
      DOI: 10.1002/cssc.201700663
       
  • Carbon dioxide capture by aqueous ionic liquid solutions
    • Authors: Jairton Dupont; Nathalia M. Simon, Marcileia Zanatta, Francisco P. dos Santos, Marta C. Corvo, Eurico J. Cabrita
      Abstract: Confined water in aqueous solutions of imidazolium-based ionic liquids (ILs) associated with acetate and imidazolate anions react reversibly with CO2 to yield bicarbonate. Three types of CO2 sorption in these "IL-aqueous solutions" were observed: physical, CO2-imidazolium adduct generation and bicarbonate formation (up to 1.9 mol of bicarbonate/mol of IL), resulting in a 10/1 mol/mol total absorption of CO2 relative to imidazolate anions in the presence of water 1/1000 (IL/water). These sorption values are higher than the classical alkanol amines or even alkaline aqueous solutions under similar experimental conditions.
      PubDate: 2017-07-25T09:26:07.257338-05:
      DOI: 10.1002/cssc.201701044
       
  • Towards extending solar cells life time : Addition of a fluorous cation to
           triple-cation based perovskite films
    • Authors: Manuel Salado; M Asunción Fernández, Juan P Holgado, Samrana Kazim, M. K. Nazeeruddin, P J Dyson, Shahzada Ahmad
      Abstract: Organo metal halide perovskites have emerged as highly promising replacements for thin film solar cells. However, their poor stability under ambient conditions remains problematic, hindering commercial exploitation. Here, we describe our investigation on the incorporation of a fluorous-functionalized imidazolium cation in a highly stable cesium based mixed perovskite material (Cs0.05(MA0.15FA0.85)0.95Pb(I0.85Br0.15)3 and how it influnce enhances stability. The resulting materials, which vary according to the content of the fluorous-functionalized imidazolium cation, display a prolonged tolerance to atmospheric humidity (>100 days) along with power conversion efficiencies exceeding 16%. This work provides a general route which can be implemented in variety of perovskites and highlights a promising way to increase perovskite solar cell stability.
      PubDate: 2017-07-25T04:20:28.148225-05:
      DOI: 10.1002/cssc.201700797
       
  • Pseudocapacitive desalination of brackish water and seawater via vanadium
           pentoxide decorated multi-walled carbon nanotubes
    • Authors: Juhan Lee; Pattarachai Srimuk, Katherine Aristizabal, Choonsoo Kim, Soumyadip Choudhury, Yoon-Chae Nah, Frank Mücklich, Volker Presser
      Abstract: We introduce membrane pseudocapacitive deionization (MPDI) of a hybrid cell consisting of one electrode of hydrated vanadium pentoxide (hV2O5) decorated on multi-walled carbon nanotubes electrode (MWCNT) and one electrode of activated carbon. This hybrid system enables sodium removal by pseudocapacitive intercalation to MWCNT-hV2O5 electrode and chloride removal by non-Faradaic electrosorption of the porous carbon electrode. MWCNT-hV2O5 electrode was synthesized by electrochemical deposition of hydrated vanadium pentoxide on the MWCNT paper. The stable electrochemical operating window for MWCNT-hV2O5 electrode is identified between -0.5 V and +0.4 V vs. Ag/Cl which provides a specific capacity of 44 mAh/g (corresponds with 244 F/g) in aqueous 1 M NaCl. The desalination performance of the MPDI system was investigated in aqueous 200 mM NaCl (brackish water) and 600 mM NaCl (sea water) solutions. With the aid of an anion and a cation exchange membrane, the MPDI hybrid cell was operated from -0.4 V to +0.8 V cell voltage without crossing the reduction and oxidation potential limit of both electrodes. For the 600 mM NaCl solution, the NaCl salt adsorption capacity of the cell was 23.6±2.2 mg/g which is equivalent to 35.7±3.3 mg/g as normalized to the mass of the MWCNT-hV2O5 electrode. Additionally, we propose a normalization method for the electrode material with Faradaic reactions based on sodium uptake capacities.
      PubDate: 2017-07-25T03:00:34.188848-05:
      DOI: 10.1002/cssc.201701215
       
  • 1D and 2D NMR spectroscopy of bonding interactions within stable and
           phase-separating organic electrolyte-cellulose solutions
    • Authors: Matthew T. Clough; Christophe Fares, Roberto Rinaldi
      Abstract: Organic electrolyte solutions (mixtures containing an ionic liquid and a polar, molecular co-solvent) are highly versatile solvents for cellu-lose. However, the underlying solvent-solvent and solvent-solute interactions are not yet fully understood. Herein, mixtures of the ionic liquid 1-ethyl-3-methylimidazolium acetate, the co-solvent 1,3-dimethyl-2-imidazolidinone, and cellulose are investigated using 1D and 2D NMR spectroscopy. The use of a triply-13C-labelled ionic liq-uid enhances the signal-to-noise ratio for 13C NMR spectroscopy, enabling changes in bonding interactions to be accurately pinpoint-ed. Current observations reveal an additional degree of complexity regarding the distinct roles of cation, anion and co-solvent toward maintaining cellulose solubility and phase stability. Unexpectedly, the interactions between the dialkylimidazolium ring C2-H substituent and cellulose become more pronounced at high temperatures, coun-teracted by a net weakening of acetate-cellulose interactions. More-over, for mixtures that exhibit critical solution behaviour, phase sepa-ration is accompanied by the apparent recombination of cation-anion pairs.
      PubDate: 2017-07-24T04:20:23.797875-05:
      DOI: 10.1002/cssc.201701042
       
  • Nanofiltration-enabled in situ solvent and reagent recycle for sustainable
           continuous-flow synthesis
    • Authors: Tamas Fodi; Christos Didaskalou, Jozsef Kupai, Gyorgy T Balogh, Peter Huszthy, Gyorgy Szekely
      Abstract: The solvent usage in the pharmaceutical sector accounts for as much as 90% of the overall mass during manufacturing processes. Consequently, solvent consumption poses significant costs and environmental burden. Continuous processing, in particular continuous-flow reactors have a great potential in the sustainable production of pharmaceuticals but subsequent downstream processing remains challenging. Separation processes for the concentration and purification of chemicals can account for as much as 80% of the total manufacturing costs. In this work, a nanofiltration unit was coupled to a continuous-flow rector for in situ solvent and reagent recycle. The nanofiltration unit is straightforward to implement and control in a continuous operation. The hybrid process was continuously operated over 6 weeks recycling about 90% of the solvent and the reagent. Consequently, the E factor and the carbon footprint were reduced by 91% and 19%, respectively. Moreover, the nanofiltration unit concentrated the product 11 times and simultaneously increased the purity from 52.4% to 91.5%. The boundaries for process conditions were investigated to facilitate implementation of the methodology by the pharmaceutical sector.
      PubDate: 2017-07-23T21:30:52.310444-05:
      DOI: 10.1002/cssc.201701120
       
  • Impact of Interfacial Layers in Perovskite Solar Cells
    • Authors: An-Na Cho; Nam-Gyu Park
      Abstract: Perovskite solar cell (PCSs) is composed of organic-inorganic lead halide perovskite as light harvester. Since the first report on long-term durable 9.7% efficient solid-state perovskite solar cell in 2012, organic-inorganic halide perovskite received great attention because of its superb opto-electronic properties. As a result, a power conversion efficiency (PCE) exceeding 22% was certified. Controlling grain size and grain boundary of perovskite layer perovskite is important for attaining high efficiency. In addition, interfacial engineering is equally or more important to improve further PCE via better charge collection and reduction in charge recombination. In this article, type of interfacial layers and their impacts on photovoltaic performance are investigated for the normal and inverted architectures. Grain boundary engineering is also included because it is related to interfacial engineering and grain boundary in perovskite layer plays important role in charge conduction, recombination and carrier life time.
      PubDate: 2017-07-23T21:30:22.262051-05:
      DOI: 10.1002/cssc.201701095
       
  • Vinylation of Aryl Ether (Lignin β-O-4 Linkage) and Epoxides with Calcium
           Carbide via C-O Bond Cleavage
    • Authors: Yugen Zhang; Siew Ping Teong, Jenny Lim
      Abstract: Calcium carbide has been increasingly used as a sustainable, easy-to-handle, and low-cost feedstock in organic synthesis. Currently, methodologies of using calcium carbide as "solid acetylene" in synthesis are strictly limited to activation and reaction with X-H (X = C, N, O, S) bonds. Herein, a mild and transition metal-free protocol was developed for the vinylation of epoxides and aryl ether linkage (β-O-4 lignin model compound) with calcium carbide via C-O bond cleavage, forming valuable vinyl ether products. CaC2 plays a vital role in the C-O bond activation and cleavage, and in providing acetylide source for the formation of vinylated products. These exciting results may provide new methodologies for organic synthesis and new insights towards lignin or biomass-related degradation to useful products.
      PubDate: 2017-07-20T21:16:34.259859-05:
      DOI: 10.1002/cssc.201701153
       
  • Plasmonic Gold Nanostars Incorporated into High-Efficiency Perovskite
           Solar Cells
    • Authors: Munkhbayar Batmunkh; Thomas Macdonald, William Peveler, Abdulaziz Bati, Claire J. Carmalt Claire J. Carmalt, Ivan Parkin, Joseph George Shapter
      Abstract: Incorporating appropriate plasmonic nanostructures into photovoltaic (PV) systems is of great utility for enhancing photon absorption and thus improving device performance. Herein, the successful integration of plasmonic gold nanostars (AuNSs) into mesoporous TiO2 photoelectrodes for perovskite solar cells (PSCs) is reported. The PSCs fabricated with TiO2-AuNSs photoelectrodes exhibited a device efficiency of up to 17.72%, while the control cells without AuNSs showed a maximum efficiency of 15.19%. We attribute the origin of increased device performance to enhanced light absorption and suppressed charge recombination.
      PubDate: 2017-07-20T10:10:29.212744-05:
      DOI: 10.1002/cssc.201701056
       
  • Corrigendum: Sustainable Gel Electrolyte Containing Pyrazole as Corrosion
           Inhibitor and Dendrite Suppressor for Aqueous Zn/LiMn2O4 Battery
    • Authors: Tuan K. A. Hoang; The Nam Long Doan, Julie Hyeonjoo Cho, Jane Ying Jun Su, Christine Lee, Changyu Lu, P. Chen
      PubDate: 2017-07-20T07:55:22.21873-05:0
      DOI: 10.1002/cssc.201701244
       
  • C-H carboxylation of aromatic compounds via CO2 fixation
    • Authors: Junfei Luo; Igor Larrosa
      Abstract: Carbon dioxide (CO2) represents the most abundant and accessible carbon source in Earth. Thus the ability to transform CO2 into valuable commodity chemicals via construction of C-C bonds is an invaluable strategy. Carboxylic acids and derivatives, the main products obtained by carboxylation of carbon nucleophiles by reaction of CO2, have wide application in pharmaceuticals and advanced materials. Among the variety of carboxylation methods currently available, the direct carboxylation of C-H bonds with CO2 has attracted much attention due to its advantages from a step- and atom-economical point of view. In particular, the prevalence of (hetero)aromatic carboxylic acid and derivatives among biologically active compounds has led to significant interest in the development of methods for their direct carboxylation from CO2. In this review will discuss the latest achievements in the area of direct C-H carboxylation of (hetero)aromatic compounds with CO2.
      PubDate: 2017-07-19T09:10:46.09985-05:0
      DOI: 10.1002/cssc.201701058
       
  • In-Situ Growth and Wrapping of Aminoanthraquinone Nanowires within 3D
           Graphene Framework as High-Performance Foldable Organic Cathode for
           Lithium Ion Batteries
    • Authors: Guanhui Yang; Fanxing Bu, Yanshan Huang, Yu Zhang, Imran Shakir, Yuxi Xu
      Abstract: Small conjugated carbonyl compounds are intriguing candidates of organic electrode materials because of their abundance, high theoretical capacity and adjustable molecular structure. However, their dissolution in aprotic electrolytes and poor conductivity eclipse them in terms of practical capacity, cycle life and rate capability. Herein, we report a foldable and binder-free nanocomposite electrode consisting of 2-aminoanthraquinone (AAQ) nanowires wrapping within three-dimensional (3D) graphene framework, which is prepared through antisolvent crystallization followed by a facile chemical reduction and self-assembly process. The nanocomposite exhibited a very high capacity of 265 mAh g-1 at 0.1 C for the AAQ, realizing 100% utilization of active material. Furthermore, the nanocomposite shows superior cycling stability (82% capacity retention after 200 cycles at 0.2 C and 76% capacity retention after 1000 cycles at 0.4 C) and excellent rate performance (153 mAh g-1 at 5 C). Particularly, the nanocomposite can deliver the highest capacity of 165 mAh g-1 among all reported anthraquinone and its analogues-based electrodes if based on the mass of the whole electrode, which is essential for practical application. Such outstanding electrochemical performance could be largely attributed to the wrapping structure of the flexible composite, which provides both conductivity and structural integrity.
      PubDate: 2017-07-19T00:30:30.793299-05:
      DOI: 10.1002/cssc.201701175
       
  • A Hydroxamic Acid Anchoring Group for Durable Dye-Sensitized Solar Cells
           with a Cobalt Redox Shuttle
    • Authors: Tomohiro Higashino; Yuma Kurumisawa, Ning Cai, Yamato Fujimori, Yukihiro Tsuji, Shimpei Nimura, Daniel Packwood, Jaehong Park, Hiroshi Imahori
      Abstract: A hydroxamic acid group has been employed for the first time as an anchoring group for cobalt-based dye-sensitized solar cells (DSSCs). The porphyrin dye YD2-o-C8HA with the hydroxamic acid anchoring group exhibited a power conversion efficiency (η) of 6.4%, which is close to that of YD2-o-C8, a representative porphyrin dye with a conventional carboxylic acid one. More importantly, YD2-o-C8HA was found to be superior to YD2-o-C8 in terms of both binding ability to TiO2 and durability of cobalt-based DSSCs. Notably, YD2-o-C8HA cell revealed a higher η-value (4.1%) than YD2-o-C8 (2.8%) after 500 h illumination. These results exemplify that the hydroxamic acid can be used for DSSCs with any transition metal-based redox shuttle to ensure high cell durability as well as excellent photovoltaic performance.
      PubDate: 2017-07-18T23:35:44.153038-05:
      DOI: 10.1002/cssc.201701157
       
  • A new perspective on transparent wood: Lignin-retaining transparent wood
    • Authors: Yuanyuan Li; Qiliang Fu, Ramiro Rojas, Min Yan, Martin Lawoko, Lars Berglund
      Abstract: Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt% of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Meanwhile, lignin removal weakens the wood structure, limiting the fabrication of large structure. Here, a green and industrially feasible method was introduced to prepare transparent wood. Up to 80 wt% of lignin was preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high lignin content transparent wood with transmittance of 83%, haze of 75%, thermal conductivity of 0.23 W/mK, and work-to-fracture of 119.5 J/m3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained is positioned for energy saving buildings.
      PubDate: 2017-07-18T09:50:17.458518-05:
      DOI: 10.1002/cssc.201701089
       
  • In-situ preparation of novel
           layered-spinel-microsphere/reduced-graphene-oxide heterostructured cathode
           for ultrafast charge-discharge Li-ion batteries
    • Authors: Dong Luo; Shaohua Fang, Li Yang, Shin-ichi Hirano
      Abstract: Although Li-rich layered oxides (LLOs) have the highest capacity of any cathodes used at present, their current rate capability is far from meeting the requirements of electric vehicles and smart grids. Here, a novel layered-spinel-microsphere/rGO (LS@rGO) heterostructured cathode is prepared by in-situ technique. This cathode is composed of a spinel phase, two layered structures and a few of reduced graphene oxide (rGO, 1.08 wt% of carbon). It delivers a considerably competitive capacity (145 mA h g-1) at an ultrahigh charge-discharge rate of 60 C (12 A g-1). The ultra-superior rate capability of LS@rGO is closely related with the in-situ introduction of spinel phase and rGO. Moreover, XAS and XPS data indicate Cr ions move from octahedral lattice sites to tetrahedral lattice sites and Mn ions do not participate in the oxidation reaction during the initial charge process.
      PubDate: 2017-07-17T22:16:23.479071-05:
      DOI: 10.1002/cssc.201701207
       
  • Metal–Organic Framework-Derived FeCo-N-Doped Hollow Porous Carbon
           Nanocubes for Electrocatalysis in Acidic and Alkaline Media
    • Authors: Xinzuo Fang; Long Jiao, Shu-Hong Yu, Hai-Long Jiang
      Abstract: Metal–organic frameworks (MOFs) are ideal precursors/ templates for porous carbons with homogeneous doping of active components for energy storage and conversion applications. Herein, metalloporphyrinic MOFs, PCN-224-FeCo, with adjustable molar ratio of FeII/CoII alternatively residing inside the porphyrin center, were employed as precursors to afford FeCo-N-doped porous carbon (denoted as FeCo-NPC) by pyrolysis. Thanks to the hollow porous structure, the synergetic effect between highly dispersed FeNx and CoNx active sites accompanied with a high degree of graphitization, the optimized FeCo2-NPC-900 obtained by pyrolysis at 900 °C exhibits more positive half-wave potential, higher diffusion-limited current density, and better stability than the state-of-the-art Pt/C, under both alkaline and acidic media. More importantly, the current synthetic approach based on MOFs offers a rational strategy to structure- and composition-controlled porous carbons for efficient electrocatalysis.Double-sided cubes: Porphyrinic metal–organic frameworks are employed to produce hollow porous carbon nanocubes with homogeneous FeNx and CoNx dopants by pyrolysis. Thanks to this particular structure, high surface area and synergetic contributions between FeNx and CoNx, the optimized FeCo2-NPC-900 exhibits excellent activity, long-term stability, and MeOH tolerance, surpassing the Pt/C, toward oxygen reduction electrocatalysis in both acidic and alkaline media.
      PubDate: 2017-07-17T06:45:54.410337-05:
      DOI: 10.1002/cssc.201700864
       
  • A multi-objective optimisation including results of life cycle assessment
           in developing bio-renewables-based processes
    • Authors: Daniel Helmdach; Polina Yaseneva, Parminder K Heer, Artur M Schweidtmann, Alexei Lapkin
      Abstract: A decision support tool has been developed, which uses global multi-objective optimisation based on: (i) the environmental impacts, evaluated within the framework of full life cycle assessment, and (ii) process costs, evaluated using rigorous process models. This approach is particularly useful in developing the bio renewable-based energy solutions and chemicals manufacturing, where multiple criteria must be evaluated and where the optimisation-based decision making process is particularly attractive. The framework is demonstrated using a case study of conversion of terpenes derived from bio-waste feedstocks into reactive intermediates. A two-step chemical conversion/separation sequence was implemented as a rigorous process model and combined with a life cycle model. A life cycle inventory for crude sulfate turpentine was developed, as well as a conceptual process of its separation into pure terpene feedstocks. The performed single- and multi-objective optimisations demonstrate the functionality of the optimisation-based process development and illustrate the approach. Most significant advance is the ability to perform multi-objective global optimisation, resulting in identification of a region of Pareto-optimal solutions.
      PubDate: 2017-07-17T06:16:09.535518-05:
      DOI: 10.1002/cssc.201700927
       
  • One-Step Cationic Grafting of 4-Hydroxy-TEMPO and its Application in a
           Hybrid Redox Flow Battery with a Crosslinked PBI Membrane
    • Authors: Zhenjun Chang; Dirk Henkensmeier, Ruiyong Chen
      Abstract: By using a one-step epoxide ring-opening reaction between 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (4-hydroxy-TEMPO) and glycidyltrimethylammonium cation (GTMA+), we synthesize a cation-grafted TEMPO (g+-TEMPO) and study its electrochemical performance against a Zn2+/Zn anode in a hybrid redox flow battery. To conduct Cl- counter anions, a crosslinked methylated polybenzimidazole (PBI) membrane was prepared and placed between the catholyte and anolyte. Compared to 4-hydroxy-TEMPO, the positively charged g+-TEMPO exhibits enhanced reaction kinetics. Moreover, flow battery tests with g+-TEMPO show improved coulombic, voltage and energy efficiencies and cycling stability over 140 cycles. Crossover of active species through the membrane was not detected.
      PubDate: 2017-07-17T02:15:32.534915-05:
      DOI: 10.1002/cssc.201701060
       
  • Decorating separator with macro/mesoporous Co-N-C for highly efficient
           polysulfides confinement and reutilization in lithium-sulfur batteries
    • Authors: Wen Hu; Yuichiro Hirota, Yexin Zhu, Nao Yoshida, Manabu Miyamoto, Tao Zheng, Norikazu Nishiyama
      Abstract: A macro/mesoporous Co-N-C-decorated separator is proposed to confine and reutilize migrating polysulfides. Endowed with desirable structure and synchronous lithio/sulfiphilic chemistry, macro/mesoporous Co-N-C interface manipulates large polysulfides adsorption uptake, high polysulfides adsorption kinetics, reversible electrocatalysis toward anchored-polysulfides redox, and facile charge transport. It significantly boosts simple MWCNT/S-70wt% cathode achieving high initial capacities (e.g. 1406 mAh g-1 at 0.2 C, 1203 mAh g-1 at 1 C), nearly 100% Coulombic efficiencies, and high reversible capacities after cycle tests (e.g. 828.4 mAh g-1 at 1 C after 100 cycles) at both low and high current rates. These results demonstrate that decorating separator with macro/meso Co-N-C paves a feasible way for developing advanced Li-S batteries.
      PubDate: 2017-07-14T05:25:35.777488-05:
      DOI: 10.1002/cssc.201700999
       
  • Low dimensional organic-inorganic halide perovskite: structure,
           properties, and applications
    • Authors: Ravi K.Misra; Bat-El Cohen, Lior Iagher, Lioz Etgar
      Abstract: Three-dimensional (3D) perovskite has attracted a lot of attention due to its success in photovoltaic (PV) solar cells. However, one the major crucial issues lies in its stability, which has limited its commercialization. An important property of organic-inorganic perovskite is the possibility of forming a layered material using long organic cations that do not fit into the octahedral cage. The long organic cation acts as a "barrier" that "caps" the 3D perovskite forming the layered material. Controlling the number of perovskite layers could provide a confined structure with different chemical and physical properties than 3D perovskite has. This opens up a whole new batch of interesting materials with huge potential for optoelectronic applications. This mini review presents the synthesis, properties, and structural orientation of low-dimensional perovskite. It also discusses the progress of low-dimensional perovskite in PV solar cells, which, to date, have a comparable performance but with enhanced stability in comparison with the 3D perovskite. Finally, the use of low-dimensional perovskite in LEDs and photodetectors is discussed. The low-dimensional perovskites are promising candidates for LED devices, mainly due to their high radiative recombination as a result of the confined low-dimensional quantum well.
      PubDate: 2017-07-13T10:25:26.032361-05:
      DOI: 10.1002/cssc.201701026
       
  • Hybrid deep eutectic solvents with flexible hydrogen-bonded supramolecular
           network for highly efficient uptake of NH₃
    • Authors: Yuhui Li; Mohammad Chand Ali, Qiwei Yang, Zhiguo Zhang, Zongbi Bao, Baogen Su, Huabin Xing, Qilong Ren
      Abstract: The serious environmental problems of modern society creates a great demand for the efficient uptake of NH₃ by solvents. However, many shortcomings exist with the traditional aqueous absorbents, and efforts to use ionic liquids met limited success. In this work, we for the first time report that the design of hybrid deep eutectic solvents (DESs) with flexible hydrogen-bonded supramolecular network enabled both exceptional NH₃ uptake capacity and superior desorption-regeneration performance, along with superb NH₃/CO₂ selectivity and environmental merits. Elucidated by the molecular dynamic simulations and spectrum analysis, the abundant hydrogen-bonding sites in the hybrid DESs grasp the every atom of NH₃ molecule and enable a strong physical reversible solvation, while the multiple interactions among the hybrid components create a flexible hydrogen-bonded supramolecular network and allow for solvent-unbreaking absorption to ensure the full participation of solvent and process stability. A mass solubility of NH₃ up to 0.13 gg-¹ was achieved at 313 K and 101 kPa by the hybrid DES choline chloride/resorcinol/glycerol (1:3:5), higher than all reported ionic liquids and ordinary DESs, and the performance remained the same after ten absorption-desorption cycles with easy regeneration. These results set a new benchmark for the reversible NH₃ absorption and separation by solvents, and would also inspire the more applications of DESs.
      PubDate: 2017-07-13T06:25:23.35114-05:0
      DOI: 10.1002/cssc.201701135
       
  • Efficient Electron Transfer across ZnO-MoS2-RGO Heterojunction for
           Remarkably Enhanced Sunlight Driven Photocatalytic Hydrogen Evolution
    • Authors: Suneel Kumar; Nagappagari Lakshmana Reddy, Himmat Singh Kushwaha, Ashish Kumar, Muthukonda Venkatakrishnan Shankar, Kaustava Bhattacharyya, Aditi Halder, Venkata Krishnan
      Abstract: Development of noble metal free catalysts for hydrogen evolution is the need of the hour for energy applications. In this regard, we designed and synthesized ternary heterojunction nanocomposites, consisting of ZnO nanoparticles anchored on MoS2-RGO nanosheets, as heterogeneous catalysts for highly efficient photocatalytic hydrogen (H2) evolution. In photocatalytic process, catalyst dispersed in electrolytic solution (S2-, SO32-) recorded an enhanced rate of H2 evolution and the optimization experiments reveals that ZnO with 4.0 wt% of MoS2-RGO nanosheets (ZMG4) showed the highest photocatalytic H2 production of 28.616 mmol h-1 gcat-1 under sunlight irradiation, which is about 56 times higher than bare ZnO and several times higher than other ternary photocatalysts. The superior catalytic activity can be attributed to in situ generation of ZnS, which leads to improved interfacial charge transfer to cocatalyst MoS2, in turn RGO where plenty of active sites available for photocatalytic reaction. The recyclability experiments of optimized photocatalyst proved its stability. In addition, the ternary nanocomposites also show its multi-functional properties for hydrogen evolution activity under electrocatalytic and photoelectrocatalytic conditions due to the high electrode-electrolyte contact area. Thus, the present work provides very useful insights in the development of inexpensive, multi-functional catalysts without noble metal loading to achieve high rate of H2 generation.
      PubDate: 2017-07-13T05:30:34.331303-05:
      DOI: 10.1002/cssc.201701024
       
  • Poly(ethylene glycol)s as Ligands in Calcium-Catalyzed Cyclic Carbonate
           Synthesis
    • Authors: Johannes Steinbauer; Thomas Werner
      Abstract: Herein the use of CaI2 in combination with poly(ethylene glycol) dimethyl ether (PEG DME 500) as an efficient catalyst system for the addition of CO2 to epoxides is reported. This protocol is based on a nontoxic and abundant metal in conjunction with a polymeric ligand. Fifteen terminal epoxides were converted at room temperature to give the desired products in yields up to 99 %. Notably, this system was also effective for the synthesis of twelve challenging internal carbonates in yields up to 98 %.Ca-talysis: Calcium-based catalyst systems using inexpensive and biocompatible ligands for the synthesis of cyclic carbonates from epoxides and CO2 are reported. This scalable reaction protocol can be used for the synthesis of terminal carbonates at room temperature as well as for the synthesis of internal carbonates below 100 °C.
      PubDate: 2017-07-12T01:08:55.682103-05:
      DOI: 10.1002/cssc.201700788
       
  • Ionic Liquid/Metal–Organic Framework Composites: From Synthesis to
           Applications
    • Authors: Fatma Pelin Kinik; Alper Uzun, Seda Keskin
      Abstract: The Back Cover picture shows the transformation of a dry field into a productive one by planting ionic liquids (ILs) on metal–organic frameworks (MOF), where the opportunities offered by the IL/MOF composites are shown as fruits on a tree. More details can be found in the Review by Kinik et al. (
      DOI : 10.1002/cssc.201700716).
      PubDate: 2017-07-11T05:56:04.39496-05:0
       
  • Brownmillerite-type Ca2FeCoO5 as a Practicable Oxygen Evolution Reaction
           Catalyst
    • Authors: Etsushi Tsuji; Teruki Motohashi, Hiroyuki Noda, Damian Kowalski, Yoshitaka Aoki, Hajime Tanida, Junji Niikura, Yukinori Koyama, Masahiro Mori, Hajime Arai, Tsutomu Ioroi, Naoko Fujiwara, Yoshiharu Uchimoto, Zempachi Ogumi, Hiroki Habazaki
      Abstract: Invited for this month′s cover is the group of Prof. Dr. Hiroki Habazaki at Hokkaido University with their collaborators from Kanagawa University, Kyoto University, and the National Institute of Advanced Industrial Science and Technology. The image shows the oxygen evolution reaction on brownmillerite-type Ca2FeCoO5 categorized as an oxygen-deficiency-ordered perovskite in a basic solution. The Communication itself is available at 10.1002/cssc.201700499.“Our discovery of the remarkable OER activity will stimulate researchers’ renewed interest…” This and more about the story behind the research that inspired the Cover image is presented in the Cover Profile. Read the full text of the corresponding research at 10.1002/cssc.201700499. View the Front Cover here: 10.1002/cssc.201701191.
      PubDate: 2017-07-11T05:55:56.971058-05:
      DOI: 10.1002/cssc.201701192
       
  • Brownmillerite-type Ca2FeCoO5 as a Practicable Oxygen Evolution Reaction
           Catalyst
    • Authors: Etsushi Tsuji; Teruki Motohashi, Hiroyuki Noda, Damian Kowalski, Yoshitaka Aoki, Hajime Tanida, Junji Niikura, Yukinori Koyama, Masahiro Mori, Hajime Arai, Tsutomu Ioroi, Naoko Fujiwara, Yoshiharu Uchimoto, Zempachi Ogumi, Hiroki Habazaki
      Abstract: The Cover picture shows the oxygen evolution reaction (OER) on brownmillerite (BM)-type Ca2FeCoO5, which is categorized as an oxygen-deficiency-ordered perovskite-type oxide containing a layered arrangement of tetrahedral (Td) and octahedral (Oh) sites. Here, remarkable OER catalytic activity of this oxide is reported. Our study suggests that the combination of Td/Oh sites in the BM structure plays a crucial role and that this oxide is a promising OER catalyst that can be used in many energy conversion technologies such as metal–air secondary batteries and hydrogen production from electrochemical/photocatalytic water splitting. More details can be found in the Communication by Tsuji et al. (
      DOI : 10.1002/cssc.201700499).
      PubDate: 2017-07-11T05:55:54.419173-05:
       
  • Conversion of cellulose to amphiphilic alkyl glycosides catalyzed by
           Aquivion, a perfluorosulfonic acid polymer
    • Authors: François Jérôme; Karine De Oliveira Vigier, Ayman Karam, Boris Estrine, Sinisa Marincovic, Claudio Oldani
      Abstract: Aquivion PFSA PW98 is an amphiphilic solid superacid capable of converting cellulose to Amphiphilic Alkyl Glycosides (AAG) in 85% yield (i.e. 97% selectivity). The present process involves (1) a mechanocatalytic depolymerization of cellulose followed by (2) a direct glycosylation with n-dodecanol. In comparison to H2SO4 and solid acid catalysts commonly employed in cellulose processing, Aquivion PFSA PW98 is not only recyclable but also exhibits superior catalytic performances in terms of yield, selectivity and reactor productivity
      PubDate: 2017-07-11T05:43:54.064286-05:
      DOI: 10.1002/cssc.201700903
       
  • Homologous Catalysts Based on Fe-Doped CoP Nanoarray toward
           High-Performance Full Water Splitting under Benign Conditions
    • Authors: Min Ma; Guilei Zhu, Fengli Qu, Zhiang Liu, Gu Du, Abdullah M. Asiri, Yadong Yao, Xuping Sun
      Abstract: The design and development of earth-abundant electrocatalysts for efficient full water splitting under mild conditions are highly desired but still remain a challenging task. In this study, we describe the development of homologous Fe-doped Co-based nanoarray as complementary catalysts for high-performance and durable water splitting in near-neutral media. Fe-doped Co-phosphate-borate nanoarray on carbon cloth (Fe-Co-Pi-Bi/CC) derived from Fe-doped CoP nanoarray on CC (Fe-CoP/CC) via oxidative polarization behaves as a highly active bimetallic electrocatalyst for water oxidation with the demand of overpotential of 382 mV to afford a geometrical catalytic current density of 10 mA cm-2 in 0.1 M potassium borate (K-Bi, pH: 9.2). Fe-CoP/CC is also superior in activity for hydrogen evolution reaction, capable of driving 10 mA cm-2 at overpotential of only 175 mV in 0.1 M K-Bi. The two-electrode water electrolyser using Fe-Co-Pi-Bi/CC as anode and Fe-CoP/CC as cathode achieves 10 mA cm-2 water splitting current at a cell voltage of 1.95 V with strong long-term electrochemical durability.
      PubDate: 2017-07-10T10:41:47.819842-05:
      DOI: 10.1002/cssc.201700693
       
  • Cooking with active oxygen and solid alkali (CAOSA): a promising
           alternative approach for lignocellulosic biorefineries
    • Authors: Yetao Jiang; Xianhai Zeng, Rafael Luque, Xing Tang, Yong Sun, Tingzhou Lei, Shijie Liu, Lu Lin
      Abstract: Lignocellulosic biomass, a matrix of the biopolymers including cellulose, hemicellulose and lignin, has gathered increasing attention in recent years in the production of chemicals, fuels and materials based on biorefinery processes due to its renewability and availability. Fractionating lignocellulose is considered as the foundational step to establish an economical and sustainable lignocellulosic biorefinery. This Minireview summarized a newly developed oxygen delignification for lignocellulose fractionation called cooking with active oxygen and solid alkali (CAOSA), which could fractionate lignocellulose into its constituents while remaining in processable form. In the CAOSA approach, environmentally-friendly chemicals were applied instead of undesirable chemicals including strong alkalis and sulfides. Notably, the alkali recovery for this process promised to be relatively simple, neither causticizing nor sintering. These features made the CAOSA process an alternative for both lignocellulose fractionation and biomass pretreatment. Advantages and challenges have also been discussed in order to provide a comprehensive perspective with respect to existing strategies.
      PubDate: 2017-07-10T06:15:22.111817-05:
      DOI: 10.1002/cssc.201700906
       
  • Influence of the Water Phase State on the Thermodynamics of Aqueous Phase
           Reforming for Hydrogen Production
    • Authors: Séverine Le Gac; Renée M Ripken, Jan Meuldijk, Johannes G.E. Gardeniers
      Abstract: : Hydrogen is a promising renewable energy source that can be produced from biomass using Aqueous Phase Reforming (APR). Here, using data obtained from AspenPlus and the literature, we evaluated the phase state, temperature-dependent enthalpy, and Gibbs free energy for the APR of small biomass model substrates. Phase equilibrium studies reveal that, under typical APR reaction conditions, the reaction mixture is in the liquid phase. Therefore, we show for the first time that the water-gas-shift (WGS), which is the second main reaction of APR, must be modeled in the liquid phase, resulting in an endothermic instead of an exothermic enthalpy of reaction. A significant implication of this finding is that, although APR has been introduced as more energy saving than conventional reforming methods, the WGS in APR has a comparable energy demand to the WGS in steam reforming (SR).
      PubDate: 2017-07-10T04:15:42.924986-05:
      DOI: 10.1002/cssc.201700189
       
  • Prominent Electron Penetration through Ultrathin Graphene Layer from FeNi
           Alloy for Efficient Reduction of CO2 to CO
    • Authors: Qingyuan Bi; Xin Wang, Feng Gu, Xianlong Du, Hongliang Bao, Guoheng Yin, Jianjun Liu, Fu-Qiang Huang
      Abstract: The chemical transformation of CO2 is an efficient approach in low-carbon energy system. The development of non-precious metal catalysts with sufficient activity, selectivity, and stability for the generation of CO by CO2 reduction under mild conditions remains a major challenge. Herein, we report a hierarchical architecture catalyst composed of ultrathin graphene shells (2-4 layers) encapsulating homogeneous FeNi alloy nanoparticles to enhance the catalytic performance. The electron transfer from the encapsulated alloy can extend from the inner to the outer shell, resulting in an increased charge density on graphene. Nitrogen atom dopants can synergistically increase the electron density on the catalyst surface and modulate the adsorption capability for acidic CO2 molecules. The optimized FeNi3@NG with prominent electron penetration through the graphene layer exhibits an excepti-onal CO2 conversion of 20.2% with a CO selectivity of nearly 100%, as well as excellent thermal stability at 523 K.
      PubDate: 2017-07-10T02:15:23.37386-05:0
      DOI: 10.1002/cssc.201700787
       
  • High Efficiency MAPbI3 Perovskite Solar Cell Using a Pure Thin Film of
           Polyoxometalate as Scaffold Layer
    • Authors: Mohammad Khaledi Sardashti; Mahmoud Zendehdel, Narges Yaghoobi Nia, Davud Karimian, Mohammad Sheikhi
      Abstract: In this work, we successfully used a pure layer of [SiW11O39]8- polyoxomethalate (POM) structure as a thin film scaffold layer of CH3NH3PbI3 based perovskite solar cells (PSCs). A smooth nanoporous surface of POM cause to amazing improvement of the photocurrent density, External Quantum Efficiency (EQE) and overall efficiency of the PSCs compare to mp-TiO2 as scaffold layer. Average PCE values of 15.5% with champion device as 16.3% could achieve by using POM and sequential deposition method of perovskite layer. Furthermore, modified and defect-free POM/perovskite interface led to elimination of the anomalous hysteresis in the current-voltage curves. Open-circuit voltage decay study show promising decrease of the electron recombination in the POM based PSCs which also related to modification of POM/perovskite interface and higher electron transport inside the POM layer.
      PubDate: 2017-07-07T23:25:56.281131-05:
      DOI: 10.1002/cssc.201701027
       
  • Catalytic Hydrodeoxygenation of High Carbon Furylmethanes to Renewable
           Jet-fuel Ranged Alkanes over a Rhenium Modified Iridium Catalyst
    • Authors: Basudeb Saha; Sibao Liu, Saikat Dutta, Weiqing Zheng, Nicholas S Gould, Ziwei Cheng, Bingjun Xu, Dionisios G Vlachos
      Abstract: Renewable jet-fuel ranged alkanes are synthesized by hydrodeoxygenation of lignocellulose derived high carbon furylmethanes over ReOx modified Ir/SiO2 catalysts under mild reaction conditions. Ir-ReOx/SiO2 with a Re/Ir molar ratio of 2 exhibits the best performance, achieving a combined alkanes yield of 82-99% from C12-C15 furylmethanes. Catalyst can be regenerated in three consecutive cycles with only ~12% loss in the combined alkanes yield. Mechanistically, the furan moieties of furylmethanes undergo simultaneous ring saturation and ring opening to form a mixture of complex oxygenates consisting of saturated furan rings, mono-keto groups, and mono-hydroxy groups. Then, these oxygenates undergo a cascade of hydrogenolysis reactions to alkanes. The high yield of Ir-ReOx/SiO2 arises from a synergy between Ir and ReOx. The acidic sites of partially reduced ReOx activate the C-O bonds of the saturated furans and alcoholic groups, while the Ir sites are responsible for hydrogenation with H2.
      PubDate: 2017-07-07T10:21:11.208533-05:
      DOI: 10.1002/cssc.201700863
       
  • A comparative study of basic, amphoteric and acidic catalysts in the
           oxidative coupling of methanol and ethanol for acrolein production
    • Authors: Aleksandra Lilic; Tiantian Wei, Simona Bennici, Jean-François Devaux, Jean-Luc Dubois, Aline Auroux
      Abstract: The impact of acid/base properties (determined by adsorption microcalorimetry) of various catalysts on the cross-aldolization of acetaldehyde and formaldehyde leading to acrolein was methodically studied in oxidizing conditions starting from a mixture of methanol and ethanol. The aldol-condensation and further dehydration to acrolein were carried out on catalysts presenting various acid-base properties (MgO, Mg-Al, Mg-SiO2, NbP, and HPA-SiO2). Thermodynamic calculations revealed that cross-aldolization is always favored comparing to self-aldolization of acetaldehyde which leads to crotonaldehyde formation. The presence of strong basic sites is shown to be necessary, but a too high amount drastically increases COx production. On strong acid sites production of acrolein and carbon oxides (COx) does not increase with temperature. The optimal catalyst for this process should be amphoteric with a balanced acid-base cooperation of medium strength sites and a small amount (150 kJ mol-1).
      PubDate: 2017-07-07T09:21:27.141205-05:
      DOI: 10.1002/cssc.201701040
       
  • Concentration-gradient multi-channel flow stream membrane capacitive
           deionization cell for ultra-high desalination capacity of carbon
           electrodes
    • Authors: Choonsoo Kim; Juhan Lee, Pattarachai Srimuk, Mesut Aslan, Volker Presser
      Abstract: We present a novel multi-channel membrane flow stream capacitive deionization (MC-MCDI) concept with two flow streams to control the environment around the electrodes and a middle channel for water desalination. The introduction of side channels to our new cell design allows operation in a highly saline environment, while the feed water stream in the middle channel (conventional CDI channel) is separated from the electrodes with anion and cation exchange membranes. At a high salinity gradient between side (1000 mM) and middle (5 mM) channels, MC-MCDI exhibited an unprecedented salt adsorption capacity (SAC) of 56 mg/g in the middle channel with charge efficiency close to unity and low energy consumption. This excellent performance corresponds to a four-fold increase in desalination performance compared to the state-of-the-art in a conventional CDI cell. The enhancement originates from the enhanced specific capacitance in high molar saline media in agreement with the Gouy-Chapman-Stern theory and from a double ion desorption/adsorption process of MC-MCDI via voltage operation from -1.2 V to +1.2 V.
      PubDate: 2017-07-07T06:20:28.630583-05:
      DOI: 10.1002/cssc.201700967
       
  • Prospective Symbiosis of Green Chemistry and Energetic Materials
    • Authors: Ilya V. Kuchurov; Mikhail N. Zharkov, Leonid L. Fershtat, Nina N. Makhova, Sergei G. Zlotin
      Abstract: A global increase in the environmental pollution demands the development of new "cleaner" chemical processes. Among urgent improvements, replacement of traditional hydrocarbon-derived toxic organic solvents with neoteric solvents less harmful for the environment is one of the most vital issues. Due to favorable combination of unique properties, ionic liquids (ILs), dense gases, and supercritical fluids (SCFs) have gained considered attention as suitable green chemistry media for preparation and modification of important chemical compounds and materials. In particular, they have a significant potential in a specific and very important area of research which is associated with manufacturing and processing of high-energy materials (HEMs). These large-scale manufacturing processes, in which hazardous chemicals and extreme conditions are used, produce a huge amount of hard-to-dispose waste. Furthermore, they are risky to staff and any improvements that would reduce fire and explosion risks of the corresponding processes are highly desirable. In this review, useful applications of almost non-flammable ILs, dense gases, and SCFs (first of all, carbon dioxide) for nitration and other reactions used for manufacturing of HEMs are considered. Recent advances in the field of energetic (oxygen-balanced and hypergolic) ILs are summarized. A significant attention is paid to the SCF-based micronization techniques, which improve energetic performance of HEMs via an efficient control of morphology and particle size distribution of the HEMs fine particles, and to useful applications of SCFs in HEM processing which makes them less hazardous.
      PubDate: 2017-07-06T09:20:30.114555-05:
      DOI: 10.1002/cssc.201701053
       
  • Electrocatalytic Water Oxidation Promoted by 3D Nano-architectured
           Turbostratic δ-MnOx on Carbon Nanotube
    • Authors: Licheng Sun; Biaobiao Zhang, Yuanyuan Li, Mario Valvo, Lizhou Fan, Quentin Daniel, Peili Zhang, Linqin Wang
      Abstract: Development of manganese based water oxidation electrocatalysts is desirable for the production of solar fuels, since manganese is earth-abundant, inexpensive, non-toxic and employed by the Photosystem II in nature for billion years. Herein, we have directly constructed a 3D nanoarchitectured turbostratic δ-MnOx on carbon nanotube-modified Ni foam (MnOx/CNT/NF) by electrodeposition and a subsequent annealing process. The MnOx/CNT/NF electrode gives a benchmark catalytic current density (10 mA/cm2) at an η of 270 mV under alkaline conditions. A steady current density of 19 mA/cm2 is obtained during the electrolysis at 1.53 V for 1.0 h. To the best of our knowledge, this work represents the most efficient manganese oxide based water oxidation electrode and demonstrates that manganese oxides, as a structural and functional model of oxygen-evolving complex (OEC) in Photosystem II, can also become comparable to those of most Ni- and Co-based catalysts.
      PubDate: 2017-07-04T07:20:29.04052-05:0
      DOI: 10.1002/cssc.201700824
       
  • Effect of nitrogen doping level on the performance of N-doped carbon
           quantum dot/TiO2 composites for photocatalytic hydrogen evolution
    • Authors: Run Shi; Zi Li, Huijun Yu, Lu Shang, Chao Zhou, Geoffrey I.N. Waterhouse, Li-Zhu Wu, Tierui Zhang
      Abstract: Carbon quantum dots (CQDs) attract widespread interest for photocatalytic applications due to their low cost and excellent electron donor/acceptor properties. However, their advance-ment as visible light photosensitizers in CQDs/semiconductor nanocomposites is currently impaired by their poor quantum yields (QYs). Herein, we describe the successful fabrication of a series of nitrogen-doped CQDs (NCDs) with N/C atom ratios ranging from 0.14-0.30. NCDs with the highest N-doping level afforded a remarkable external QY of 66.8 % at 360 nm, and outstanding electron transfer properties and photosensitiza-tion efficiencies when physically adsorbed on P25 TiO2. A NCDs/P25-TiO2 hybrid demonstrated excellent performance for hydrogen evolution in aqueous methanol under both UV and visible light illumination relative to pristine P25 TiO2. Controlled nitrogen doping of CQDs therefore represents a very effective strategy for optimizing the performance of CQDs/semiconductor hybrid photocatalysts.
      PubDate: 2017-07-03T04:16:08.392395-05:
      DOI: 10.1002/cssc.201700943
       
  • Factors influencing the mechanical properties of formamidinium lead
           halides and related hybrid perovskites
    • Authors: Shijing Sun; Furkan H. Isikgor, Zeyu Deng, Fengxia Wei, Gregor Kieslich, Paul D. Bristowe, Jianyong Ouyang, Anthony K. Cheetham
      Abstract: The mechanical properties of formamidinium lead halide perovskites (FAPbX3, X = Br or I) grown by inverse temperature crystallization have been studied by nanoindentation. The measured Young's moduli (9.7 - 12.3 GPa) and hardnesses (0.36 - 0.45 GPa) indicate good mechanical flexibility and ductility. The effects of hydrogen bonding were evaluated by performing ab initio molecular dynamics on both formamidinium and methylammonium perovskites and calculating radial distribution functions. The structural and chemical factors influencing these properties are discussed by comparison with corresponding values in the literature for other hybrid perovskites, including double perovskites. Our results reveal that bonding in the inorganic framework and hydrogen bonding play important roles in determining elastic stiffness. The influence of the organic cation becomes more important for structures at the limit of their perovskite stability, indicated by high tolerance factors.
      PubDate: 2017-06-30T12:05:47.291024-05:
      DOI: 10.1002/cssc.201700991
       
  • Efficient and Highly Selective Solvent-Free Oxidation of Primary Alcohols
           to Aldehydes Using Bucky Nanodiamond
    • Authors: Yangming Lin; Kuang-Hsu (Tim) Wu, Linhui Yu, Saskia Heumann, Dangsheng Su
      Abstract: Selective oxidation of alcohols to aldehydes is widely applicable to the synthesis of various green chemicals. The poor chemo-selectivity for complicated primary aldehydes over state-of-the-art metal-free or metal-based catalysts represents a major obstacle for industrial application. Here we report on bucky nanodiamond as a potential green catalyst which exhibits excellent chemo-selectivity and cycle stability in the selective oxidation of primary alcohols in diverse structures (22 examples, including aromatic, substituted aromatic, unsaturated, heterocycle and linear chain alcohols) to their corresponding aldehydes; the results are even comparable to the reported transition metal catalysts and conventional Pt/C and Ru/C catalysts for certain substrates under solvent-free conditions. The possible activation process of surface oxygen groups and defect species to oxidant and substrate are revealed with model catalysts, ex-situ electrochemical measurement and ex-situ attenuated total reflectance. The zigzag edges of sp2 carbon planes have been shown to play a key role in these reactions.
      PubDate: 2017-06-30T10:06:29.536421-05:
      DOI: 10.1002/cssc.201700968
       
  • Minimalistic Liquid-Assisted Route to Highly Crystalline α-Zirconium
           Phosphate
    • Authors: Yu Cheng; Xiaodong (Tony) Wang, Stephan Jaenicke, Gaik-Khuan Chuah
      Abstract: Zirconium phosphates have potential applications in areas of ion-exchange, catalysis, photochemistry, and biotechnology. However, synthesis methodologies to form crystalline α-zirconium phosphate (Zr(HPO₄)₂·H₂O) typically involve the use of excess phosphoric acid, addition of HF or oxalic acid and long reflux times or hydrothermal conditions. Herein we report on a minimalistic sustainable route using only zirconium oxychloride and concentrated phosphoric acid to form highly crystalline α-zirconium phosphate within hours. The morphology can be changed from platelets to rod-shaped particles with fluoride addition. By varying the temperature and time, α-zirconium phosphate with particle sizes from nanometers to microns were obtained. Key features of this minimal solvent synthesis are the excellent yields obtained with high atom economy under mild conditions and ease of scalability.
      PubDate: 2017-06-30T08:05:19.693104-05:
      DOI: 10.1002/cssc.201700885
       
  • Impact of macroporosity on catalytic upgrading of fast pyrolysis bio-oil
           by esterification over silica sulfonic acids
    • Authors: Jinesh Manayil; Amin Osatiashtiani, Alvaro Mendoza, Christopher Parlett, Lee Durndell, Mark Isaacs, Chrysoula Michailof, Eleni Heracleous, Angelos Lappas, Adam Lee, Karen Wilson
      Abstract: Fast pyrolysis bio-oils possess unfavourable physicochemical properties and poor stability, due in large part to the presence of carboxylic acids, which hinders their use as biofuels. Catalytic esterification offers an atom and energy efficient route to upgrade pyrolysis bio-oils. Propyl sulfonic acid silicas are active for carboxylic acid esterification but suffer mass-transport limitations for bulky substrates. Macropore (200 nm) incorporation enhances the activity of mesoporous SBA-15 architectures (post-functionalised by hydrothermal saline promoted grafting) for the esterification of linear carboxylic acids, with the magnitude of turnover frequency (TOF) enhancement increasing with chain length from 5 % (C3) to 110 % (C12). Macroporous-mesoporous PrSO3H/SBA-15 also offers a two-fold TOF enhancement over its mesoporous analogue for the esterification of a real thermal fast pyrolysis bio-oil derived from woodchips. The total acid number was reduced by 57 %, with GCxGC-ToFMS evidencing ester and ether formation accompanying loss of acid, phenolic, aldehyde and ketone components.
      PubDate: 2017-06-30T05:05:52.099639-05:
      DOI: 10.1002/cssc.201700959
       
  • Hierarchical Hollow Covalent Organic Frameworks-derived Heteroatom-doped
           Carbon Spheres for Metal-free Catalysis
    • Authors: Liuyi Li; Lu Li, Caiyan Cui, Hongjun Fan, Ruihu Wang
      Abstract: Covalent organic frameworks (COFs) with hollow structures hold great promises for developing new types of functional materials. Herein, we report a hollow spherical COF with a hierarchical shell, which serves as an effective precursor of B,N-codoped hierarchical hollow carbon spheres. Benefiting from the synergistic effect of hierarchical porosity, high surface area and B,N-codoping, the as-synthesized carbon spheres show the prospective utility as metal-free catalysts in nitroarene reduction. A mechanistic hypothesis is proposed based on theoretical and experimental studies. B atoms meta to pyridinic N atoms are identified to be the main catalytic active sites. The anti-aromaticity originated from the codoping of B and pyridinic N atoms, not charge distribution and deformation energy, is corroborated to play a pivotal role in the catalytic reaction.
      PubDate: 2017-06-29T22:07:51.523633-05:
      DOI: 10.1002/cssc.201700979
       
  • Tuning the composition of bimetallic electrodeposited Sn-Pb catalysts for
           enhanced activity and durability in CO2 electroreduction to formate
    • Authors: Elod Gyenge; Colin Moore
      Abstract: Bimetallic Sn-Pb catalysts with five different Sn:Pb atomic ratios were electrodeposited on teflonated carbon paper and un-teflonated carbon cloth using both fluoroborate and oxide containing deposition media to produce catalysts for electrochemical reduction of CO2 (ERC) to formate (HCOO-). The interaction between catalyst composition, morphology, substrate and deposition media was investigated by cyclic voltammetry and constant potential electrolysis at -2.0 V vs. Ag/AgCl for 2 h in 0.5 M KHCO3. The catalysts were analyzed before and after electrolysis with scanning electron microscopy (SEM) and X-ray diffraction (XRD) to determine the mechanisms of faradaic efficiency loss and degradation. Sn majority catalysts with 15 to 35%at. Pb generated faradaic efficiencies up to 95% with stable performance. Pure Sn catalysts on the other hand, in spite of high initial stage formate production rates, experienced extensive (up to 30%) decrease of the faradaic efficiency. XRD results demonstrated the presence of polycrystalline SnO2 after electrolysis using Sn-Pb catalysts with 35%at. Pb and its absence in case of pure Sn. It is proposed that the presence of Pb (15 to 35 %at.) in Sn majority catalysts stabilized SnO2, which is responsible for the enhanced faradaic efficiency and catalytic durability in ERC.
      PubDate: 2017-06-29T21:06:26.653377-05:
      DOI: 10.1002/cssc.201700761
       
  • Benzoyl Peroxide as an Efficient Dopant for spiro-OMeTAD in Perovskite
           Solar Cells
    • Authors: Qiuju Liu; Lisheng Fan, An’an Zhou, Baozeng Wang, Hua Bai, Qingyong Tian, Bin Fan, Tongyi Zhang
      Abstract: Although organic small molecule spiro-OMeTAD is widely used as a hole transport material in perovskite solar cells, its limited electric conductivity might be a bottle-neck challenge in the efficiency improvement of perovskite solar cells. In this article, a low-cost and easy-fabrication technique is developed to enhance the conductivity and hole extraction of spiro-OMeTAD by doping it with commercially available benzoyl peroxide (BPO). The experimental results show that the conductivity increases many order in magnitude, from 6.2 × 10−6 S cm−1 of the pristine spiro-OMeTAD to 1.1 × 10−3 S cm−1 at the 5% BPO doping and to 2.4 × 10−2 S cm−1 at the 15% BPO doping, which considerably outperform the conductivity of 4.62 × 10−4 S cm−1 in the currently used oxygen doped spiro-OMeTAD. The fluorescence spectra suggest the BPO doped spiro-OMeTAD-OMeTAD layer is able to efficiently extract hole from the underneath CH3NH3PbI3 and thus greatly enhance the charge transfer. The BPO doped spiro-OMeTAD is used in the fabrication of perovskite solar cells, which exhibit the enhancement in the power conversion efficiency.
      PubDate: 2017-06-29T09:05:56.528281-05:
      DOI: 10.1002/cssc.201700872
       
  • Photovoltaic Rudorffites: Structure and Optoelectronic Properties
    • Authors: Ivan Turkevych; Said Kazaoui, Eisuke Ito, Toshiyuki Urano, Koji Yamada, Hiroshi Tomiyasu, Hideo Yamagishi, Michio Kondo, Shinji Aramaki
      Abstract: Hybrid CPbX₃ (C=Cs, CH₃NH₃; X=Br, I) perovskites are blessed with both excellent photovoltaic properties and high toxicity that hinders their practical application. Unfortunately, all Pb-free alternatives based on Sn and Ge are extremely unstable. Although stable and non-toxic C₂ABX₆ double-perovskites based on alternating corner-shared AX₆ and BX₆ octahedra (where A=Ag, Cu; B=Bi, Sb) are possible, they have indirect and wide bandgaps of over 2 eV. However, is it necessary to keep the corner-shared perovskite structure to retain good photovoltaic properties' Here, we demonstrate another family of photovoltaic halides based on edge shared AX₆ and BX₆ octahedra with the general formula AaBbXx (x=a+3b) such as Ag₃BiI₆, Ag₂BiI₅, AgBiI₄, AgBi₂I₇. As perovskites were named after their prototype oxide CaTiO₃ discovered by Lev Perovski, we propose to name these new ABX halides as rudorffites after Walter von Rudorff who discovered their prototype oxide NaVO₂. We studied structural and optoelectronic properties of several highly stable and promising Ag-Bi-I photovoltaic rudorffites that feature direct bandgaps in the range of 1.79-1.83 eV and demonstrated a proof-of-concept FTO/c-m-TiO₂/Ag₃BiI₆/PTAA/Au solar cell with photo-conversion efficiency of 4.3%.
      PubDate: 2017-06-28T22:05:24.574646-05:
      DOI: 10.1002/cssc.201700980
       
  • Sulfur-Doped Graphene Oxide Quantum Dots as Photocatalysts for Hydrogen
           Generation in the Aqueous Phase
    • Authors: Tung-Kung Wu; Jacek Gliniak, Jia-Hoa Lin, Yi-Ting Chen, Chuen-Ru Li, Efat Jokar, Chin-Hao Chang, Chun-Sheng Peng, Jui-Nien Lin, Wan-Hsiang Lien, Hui-Min Tsai
      Abstract: Sulfur-doped graphene oxide quantum dots (S-GO QDs) have been synthesized and investigated for efficient photocatalytic hydrogen generation application. The UV‒vis, FT‒IR, and photoluminescent spectra of the synthesized S-GO QDs exhibit three absorption bands at 333, 395, and 524 nm, characteristic of C=S and C-S stretching vibration signals at 1075 cm-1 and 690 cm-1, and two excitation wavelength independent emission signals with maxima at 451 and 520 nm, respectively, confirming the successful doping of S atom into the GO QDs. Electronic structural analysis suggested that the S-GO QDs exhibit conduction band minimum (CBM) and valence band maximum (VBM) levels suitable for water splitting. Under direct sunlight irradiation, an initial rate of 18166 μmol∙h-1∙g-1 in pure water and 30519 μmol∙h-1∙g-1 in 80% EtOH aqueous solution were obtained. Therefore, metal-free and inexpensive S-GO QDs hold great potential in the development of sustainable and environmental-friendly photocatalysts for efficient hydrogen generation from water-splitting.
      PubDate: 2017-06-28T03:00:22.371752-05:
      DOI: 10.1002/cssc.201700910
       
  • Replacement of Biphenyl by Bipyridine Enabling Powerful Hole Transport
           Materials for Efficient Perovskite Solar Cells with High Voc and FF
    • Authors: Fei Wu; Yahan Shan, Jianhui Qiao, Cheng Zhong, Rui Wang, Qunliang Song, Linna Zhu
      Abstract: In this work, the 2,2'- and 3,3'-bipyridine are firstly introduced as the core structure to get two new hole transport materials, namely F22 and F33. The electron-withdrawing nature of bipyridine lowers the HOMO level of the new compounds, and increases Voc of the resulting solar cells. Especially for F33, the better planarity leads to better conjugation in the whole molecule, and the HOMO level is lowered by the bipyridine center compared to F22. Hole mobility tests, steady state PL spectra as well as time-resolved PL decay results, demonstrate that the new HTMs exhibit good hole extraction and hole transporting property. Impressive power conversion efficiency of 17.71 % and 18.48 % are achieved in conventional planar perovskite (CH3NH3PbI3-xClx) solar cells containing F22 and F33 as hole transport material, respectively. As far as we know, this is the first report on bypiridine-based HTMs with leading efficiencies, and the design motif in this work opens a new way for devising hole transport materials in the future.
      PubDate: 2017-06-27T21:00:57.78097-05:0
      DOI: 10.1002/cssc.201700973
       
  • Metal Free Oxidation of Glycerol over Nitrogen Containing Carbon Nanotubes
    • Authors: Alberto Villa; Neeraj Gupta, Oleksiy Khavryuchenko, Dangsheng Su
      Abstract: Nitrogen rich carbon nanotubes have been used as a metal free catalyst for the conversion of glycerol into dihydroxyacetone using tert-Butyl hydroperoxide (TBHP) as an oxidant. Pyridine nitrogen embedded in carbon matrix is identified as an active site for the reaction. Computational studies have demonstrated that oxidation of pyridine site to pyridine oxime followed by hydrogen abstraction from secondary alcohol is most probably responsible for the oxidation process.
      PubDate: 2017-06-27T11:00:37.182406-05:
      DOI: 10.1002/cssc.201700940
       
  • Low-cost Carbazole-based Hole Transport Material for Highly Efficient
           Perovskite Solar Cells
    • Authors: Zhiliang Chen; Hui Li, Xiaolu Zheng, Qi Zhang, Zhanfeng Li, Yuying Hao, Guojia Fang
      Abstract: A low cost carbazole based small molecule material 1,3,6,8-tetra(N,N-p-dimethoxyphenylamino)-9-ethyl-carbazole was designed and synthesized using a facile three-step synthetic route. The novel material was fully characterized and further applied as hole transport material (HTM) for low temperature processed planar perovskite solar cells (PSCs). Devices based on this new HTM exhibit a high power conversion efficiency (PCE) of 17.8%, which is comparable to that (PCE of 18.6%) of the costly 2,2',7,7'-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) based PSCs.
      PubDate: 2017-06-26T22:17:38.710381-05:
      DOI: 10.1002/cssc.201700678
       
  • Sustainable Biomass-Derived Catalysts for Selective Hydrogenation of
           Nitroarenes
    • Authors: Basudev Sahoo; Dario Formenti, Christoph Topf, Stephan Bachmann, Michelangelo Scalone, Kathrin Junge, Matthias Beller
      Abstract: Development of catalytically active materials from biowaste represents an important aspect of sustainable chemical research. Three heterogeneous materials were synthesized from inexpensive biomass based chitosan and abundant Co(OAc)₂via complexation followed by pyrolysis at various temperatures. These materials were applied for the catalytic hydrogenation of nitroarenes using molecular hydrogen. A variety of diversely functionalized nitroarenes including few pharmaceutically active compounds were selectively converted to aromatic amines in high yield and selectivity with excellent functional group tolerance. As an example, this green protocol has also been implemented for the synthesis of biologically important TRPC3 inhibitor.
      PubDate: 2017-06-26T09:17:52.80268-05:0
      DOI: 10.1002/cssc.201700796
       
  • Anionic extraction for efficient recovery of bio-based 2,3-butanediol - a
           platform for bulk and fine chemicals
    • Authors: Peter Drabo; Till Tiso, Benedikt Heyman, Eda Sarikaya, Paula Gaspar, Jochen Förster, Jochen Büchs, Lars Mathias Blank, Irina Delidovich
      Abstract: 2,3-Butanediol (BDO) presents a promising platform molecule for the synthesis of basic and fine chemicals. Biotechnological production of BDO from renewable resources with living microbes enables high concentrations in the fermentation broth. The recovery of the high-boiling BDO from an aqueous fermentation broth presents the subsequent challenge. Here we propose a method for BDO isolation based on a reversible complexation with phenylboronate into an anionic complex. BDO can be recovered by back-extraction into an acidic solution. The composition of the extracted species was determined by NMR, MS, and GC-MS methods. The conditions of extraction and back-extraction were optimized using commercial BDO and finally applied to different fermentation broths. Up to 72-93% BDO can be extracted and up to 80-90% can be back-extracted under the optimized conditions. Purified bio-BDO was used in the presence of sulphuric acid for synthesis of methyl ethyl ketone (MEK), an established organic solvent and discussed tailor-made biofuel.
      PubDate: 2017-06-26T05:17:38.079088-05:
      DOI: 10.1002/cssc.201700899
       
  • Low-cost Perovskite Solar Cells Employing
           Dimethoxydiphenylamine-Substituted Bistricyclic Aromatic Enes as Hole
           Transporting Materials
    • Authors: Mohammad Khaja Nazeeruddin; Kasparas Rakstys, Sanghyun Paek, Giulia Grancini, Peng Gao, Vygintas Jankauskas, Abdullah M. Asiri
      Abstract: The synthesis, characterization and photovoltaic performance of series of novel molecular hole transporting materials (HTMs) based on bistricyclic aromatic enes (BAEs) are presented. The new derivatives have been obtained following the simple and straightforward two-step procedure from inexpensive starting reagents mimicking the synthetically challenging 9,9'-spirobifluorene moiety of the well-studied spiro-OMeTAD. The novel HTMs are tested in mixed caions and anions perovskite solar cells (PSCs) yielding power conversion efficiency (PCE) of 19.2% under standard global 100 mW cm−2 AM 1.5G illumination using 9-(2,7-bis(bis(4-methoxyphenyl)amino)-9H-fluoren-9-ylidene)-N2,N2,N7,N7-tetrakis(4-methoxyphenyl)-9H-thioxanthene-2,7-diamine (coded as KR374). The power conversion efficiency data confirms the easily attainable heteromerous fluorenylidenethioxanthene structure as valuable core for low-cost and highly efficient HTM design and paves the way towards cost-effective PSC technology.
      PubDate: 2017-06-26T04:17:33.543787-05:
      DOI: 10.1002/cssc.201700974
       
  • Mechanism of Microwave-assisted Pyrolysis of Glucose to Furfural Revealed
           by Isotopic Tracer and Quantum Chemical Calculations
    • Authors: Liwei Bao; Lei Shi, Hu Luo, Lingzhao Kong, Shenggang Li, Wei Wei, Yuhan Sun
      Abstract: Glucose labelled with 13C or 18O was used to investigate the mechanism during its conversion into furfural by microwave-assisted pyrolysis. The isotopic content and location in furfural were determined from GC/MS and 13C NMR measurements and data analysis. Our results suggest that the carbon skeleton in furfural is mainly derived from the C-1 to C-5 of glucose. The C of the aldehyde group and the O of the furan ring in furfural are primarily originated from the C-1 and O-5 of glucose, respectively. For the first time, the source of the O of the furan ring in furfural was elucidated directly by experiments, which is consistent with predictions from recent quantum chemical calculations. Furthermore, our own theoretical calculations yield substantially lower energy barriers than the previous predictions by considering the potential catalytic effect of formic acid, which is one of the pyrolysis products. The catalytic role of formic acid is further confirmed by our experimental evidence.
      PubDate: 2017-06-25T22:17:36.59933-05:0
      DOI: 10.1002/cssc.201700621
       
  • Enhancing perovskite electrocatalysis of solid oxide cells through
           controlled growth of nanoparticles
    • Authors: Bin Hua; Meng Li, Yi-Fei Sun, Jian-Hui Li, Jing-Li Luo
      Abstract: Perovskite oxides have received a great deal of attentions as promising electrodes in both solid oxide fuel cells (SOFCs) and solid oxide electrolyzer cells (SOECs) because of their reasonable reactivity, impurity tolerance, tunable property, etc. Particular explorations are still required for advancing the perovskite electrodes, which normally suffer from slow kinetics in electrocatalysis. In the past decades, several experimental studies have developed new classes of perovskites with advanced characteristics and electrode kinetics at technical levels. In parallel with those developments, the achievements in theoretical and computational studies have led to substantial understanding, at the atomic level, of their physicochemical properties and electrocatalytic behaviors. The chemical and structural flexibilities enable the perovskites to accommodate most metallic elements without destroying their complex matrix structures, thereby delivering a pathway to engineering their catalytic properties. In this contribution, we briefly introduce the recent advances in perovskite electrodes, and focus on the perovskites with exsolved nanoparticles as the enhanced electrocatalytic materials.
      PubDate: 2017-06-24T01:47:27.982784-05:
      DOI: 10.1002/cssc.201700936
       
  • Evaluating Dihydroazulene-Vinylheptafulvene Photoswitches for Solar Energy
           Storage Applications
    • Authors: Zhihang Wang; Jonas Udmark, Karl Börjesson, Rita Rodrigues, Anna Roffey, Maria Abrahamsson, Mogens B Nielsen, Kasper Moth-Poulsen
      Abstract: Efficient solar energy storage is a key challenge in striving towards a sustainable future. For this reason, molecules capable of solar energy storage and release through valence isomerization, so-called Molecular Solar Thermal energy storage (MOST), have been investigated. Here, we evaluate the energy storage potential through the photoconversion of the dihydroazulene-vinylheptafulvene (DHA/VHF) photo-thermal couple. The robust nature of this system has been determined through multiple energy storage and release cycles at elevated temperatures in three different solvents. In a non-polar solvent such as toluene, the DHA/VHF system can be cycled more than 70 times with less than 0.01% degradation per cycle. Moreover, the [Cu(CH3CN)4]PF6 catalyzed conversion of VHF to DHA was demonstrated in a flow reactor. The performance of the DHA/VHF couple was also evaluated in prototype photoconversion devices, both in the laboratory using a flow chip under simulated sunlight, and under outdoor conditions by using a parabolic mirror. Device experiments demonstrated a solar energy storage efficiency up to 0.13% in the chip device and up to 0.02% in the parabolic collector, respectively. Avenues for future improvements and optimization of the system are discussed herein.
      PubDate: 2017-06-23T10:45:24.556749-05:
      DOI: 10.1002/cssc.201700679
       
  • Quantitative insights into the Fast Pyrolysis of Extracted Cellulose,
           Hemicelluloses and Lignin
    • Authors: Marion Carrier; Michael Windt, Bernhard Ziegler, Jörn Appelt, Bodo Saake, Dietrich Meier, Anthony Bridgwater
      Abstract: The transformation of lignocellulosic biomass into bio-based commodity chemicals is technically possible. Among thermochemical processes, fast pyrolysis, a relatively mature technology that has now reached the commercial level, produces a high yield of an organic-rich liquid stream. Despite the recent efforts in elucidating the degradation paths of biomass pyrolysis, the selectivity and recovery rates of bio-compounds remain low. In an attempt to clarify the general degradation scheme of biomass fast pyrolysis and provide a quantitative insight, this study has combined the use of fast pyrolysis micro-reactors, spectrometric techniques and mixtures of unlabelled and Carbon-13 enriched materials. The first stage of the work reported aimed at selecting the type of reactor to ensure control of the pyrolysis regime. The comparison of chemical fragmentation patterns of 'primary' fast pyrolysis volatiles detectable by GC-MS between two small scale micro-reactors has shown the inevitable presence of secondary reactions. In a second stage, liquid fractions also made of 'primary' fast pyrolysis condensables have been analysed by quantitative liquid-state 13C-NMR providing a quantitative distribution of functional groups. The compilation of those results into a map that displays the distribution of functional groups according to the individual and main constituents of biomass confirmed the origin of individual chemicals within fast pyrolysis liquids.
      PubDate: 2017-06-23T07:51:02.255897-05:
      DOI: 10.1002/cssc.201700984
       
  • Hydroxyacetone: A glycerol based platform for electrocatalytic
           hydrogenation and hydrodeoxygenation processes
    • Authors: Waldemar Sauter; Olaf Lennart Bergmann, Uwe Schröder
      Abstract: Here we propose the use of hydroxyacetone, a dehydration product of glycerol, as a platform for the electrocatalytic synthesis of acetone, 1,2-propanediol and 2-propanol. 11 non-noble metals were investigated as electrode materials in combination with three different electrolyte compositions towards the selectivity, Coulomb efficiency (CE) and reaction rates of the electrocatalytic hydrogenation (formation of 1,2-propanediol) and hydrodeoxygenation (formation of acetone and propanol) of hydroxyacetone. With a selectivity of 84.5%, a reaction rate of 782 mmol/h*m2 and a CE of 32% (for 0.09 M hydroxyacetone), iron electrodes, in a chloride electrolyte, yielded the best 1,2 propanediol formation. A further enhancement of the performance can be achieved upon increasing the educt concentration to 0.5 M, yielding a reaction rate of 2248.1 mmol/ h*m² and a CE of 64.5%. Acetone formation was optimal at copper and lead electrodes in chloride solution, with lead showing the lowest tendency of side product formation. 2-propanol formation can be achieved using a consecutive oxidation of the formed acetone (at iron electrodes). 1-propanol formation was observed only in traces.
      PubDate: 2017-06-23T05:50:37.411707-05:
      DOI: 10.1002/cssc.201700996
       
  • Comprehensive insights into the thermal stability, biodegradability and
           combustion chemistry of Pyrrolidinium-based Ionic Liquids
    • Authors: Gebrekidan Gebreselassie Eshetu; Sangsik Jeong, Pascal Pandard, Amandine Lecocq, Guy Marlair, Stefano Passerini
      Abstract: The use of ionic liquids (ILs) as advanced electrolytes components in electrochemical energy storage devices is one of the most appealing and emerging options. However, though ILs are hailed as safer and eco-friendly electrolytes, overcoming the limitations imposed by the highly volatile/combustible carbonate based electrolytes, the full scale and precise appraisal of their overall safety levels under abuse conditions still need to be fully addressed. With the aim of providing the entreated level of information on the thermal and chemical stabilities as well as actual fire hazards, we embarked on a detailed investigation of the short - and long - term thermal stabilities, bio-degradability and combustion behaviour of various pyrrolidinium ([Pyr1A] +)-based ILs, enlisting different alkyl chain lengths, [Pyr1A] + (A=3-10), counter-anions ([TFSI]-/[FSI]-/[BETI]-), cations (Pyr14+/Pyr12O1+) and the effect of doping with Li salts (e.g. Li[TFSI]/[Pyr14] [TFSI]).
      PubDate: 2017-06-23T05:50:33.235195-05:
      DOI: 10.1002/cssc.201701006
       
  • Design of Iron(II) Pthalocyanine (FePc) Derived Oxygen Reduction
           Electrocatalysts for High Power Density Microbial Fuel Cells
    • Authors: Carlo Santoro; Rohan Gokhale, Barbara Mecheri, Alessandra D'Epifanio, Silvia Licoccia, Alexey Serov, Kateryna Artyushkova, Plamen Atanassov
      Abstract: Iron(II) Phthalocyanine (FePc) deposited onto two different carbonaceous supports was synthesized by the non-conventional pyrolysis-free method, studied in the reaction of oxygen reduction (ORR) in neutral media, incorporated in an air-breathing cathode structure and tested in operating microbial fuel cell (MFC) configuration. Rotating ring disk electrode (RRDE) analysis revealed high performances of the Fe-based catalysts compared with activated carbon (AC). It was shown that Black Pearls supported FePc (Fe-BP(N)) exhibits the highest performance in term of more positive onset, positive shift of half-wave potential and higher limiting as well as highest power density in operating MFC (243±7 μWcm-2) that was 33% higher than Fe-CNT(N) (182±5 μWcm-2). Power density generated by Fe-BP(N) was 92% higher than AC indicating that the utilization of PGM-free catalysts can boost up significantly the performances of MFCs.
      PubDate: 2017-06-23T04:05:35.994542-05:
      DOI: 10.1002/cssc.201700851
       
  • Molecular Self-Assembly Fabrication and Carrier Dynamics of Stable and
           Efficient CH3NH3Pb(1−x)SnxI3 Perovskite Solar Cells
    • Authors: Jiandong Fan; Chong Liu, Hongliang Li, Cuilin Zhang, Wenze Li, Yaohua Mai
      Abstract: The Sn-based perovskite solar cells (PSCs) provide the possibility that swaps the Pb element toward toxic-free PSCs. Here, we innovatively employed a molecular self-assembly approach to obtain a series CH3NH3Pb(1−x)SnxI3 (0≤x≤1) perovskite thin films with full coverage. The optimized planar CH3NH3Pb0.75Sn0.25I3 PSCs with inverted structure was consequently realized with a maximum power conversion efficiency (PCE) over 14 %, which displayed a stabilized power output (SPO) over 12 % within 200 s at 0.6 V forward bias. Afterward, we investigated the factors that limited the efficiency improvement of hybrid Sn-Pb PSCs, and analyzed the possible reason of the hysteresis effect occurred even in the inverted structure cell. Particularly, the oxidation of hybrid Sn-Pb perovskite thin film was demonstrated to be the main reason that caused the decreasing of minority-carrier lifetime, which quenched the carrier collection efficiency while the depletion layer was widened. The imbalance of charge transport was intensified that was associated with the increased hole defect-state density and decreased the electron defect-state density after Sn was introduced. This study is benefit to tackle the intractable issue regarding the toxic Pb in perovskite devices and step forward toward realizing the lead-free PSCs with high stability and efficiency.
      PubDate: 2017-06-22T20:51:01.167451-05:
      DOI: 10.1002/cssc.201700880
       
  • Nanoelectrical and Nanoelectrochemical Imaging of Pt/p-Si and Pt/p+-Si
           Electrodes
    • Authors: Jingjing Jiang; Zhuangqun Huang, Chengxiang Xiang, Rakesh Poddar, Hans-Joachim Lewerenz, Kimberly M. Papadantonakis, Nathan Lewis, Bruce Brunschwig
      Abstract: The interfacial properties of electrolessly deposited Pt nanoparticles (Pt-NP) on p-Si and p+-Si electrodes have been resolved on the nanometer scale using a combination of scanning probe methods. Atomic-force microscopy (AFM) showed highly dispersed Pt nanoparticles. Conductive AFM measurements showed that only about half of the particles exhibited measurable contact currents, with a factor of 10^3 difference in current. Local current-voltage measurements revealed a rectifying junction with a resistance of ≥ 10 MΩ at the Pt-NP/p-Si interface, while Pt-NP/p+-Si samples formed an Ohmic junction with a local resistance of ≥ 1 MΩ. The particles were strongly attached to the sample surface in air. However in contact with an electrolyte, the adhesion of the particles to the surface was substantially lower. Scanning electrochemical microscopy (SECM) showed smaller, but more uniform electrochemical currents for the particles relative to the currents observed in conductive AFM measurements. In accord with the conductive AFM measurements, SECM measurements showed conductance through the substrate for only a minority of the particles. These results suggest that the electrochemical performance of the electrolessly deposited Pt nanoparticles on Si is ascribable to: 1) the high resistance of the contact between the particles and the substrate; 2) the low (
      PubDate: 2017-06-21T12:45:47.696481-05:
      DOI: 10.1002/cssc.201700893
       
  • A Perylene-Based Polycyclic Aromatic Hydrocarbon Electron-Donor for a
           Highly Efficient Solar Cell Dye
    • Authors: Junting Wang; Heng Wu, Linrui Jin, Jing Zhang, Yi Yuan, Peng Wang
      Abstract: The continuing efforts of creating novel polycyclic aromatic hydrocarbons (PAHs) and exploiting them as the crucial building-blocks of organic donor-acceptor (D-A) dyes with excellent excited state features, should bring an unprecedented chance for the improvement of power conversion efficiency (PCE) of dye-sensitized solar cells (DSCs). In this paper we report a nonacyclic aromatic hydrocarbon, N-annulated benzoindenopentaphene (NBIP), which can be tethered with multiple solubilizing groups including one 2-hexyldecyl, one 2-hexyldecyloxy, and four 4-hexylphenyl substituents. The side- and end-chain functionalized NBIP can be conveniently prepared at an excellent yield, and further cross-coupled with 4-(7-ethynylbenzo[c][1,2,5]thiadiazol-4-yl)benzoic acid to afford a metal-free D-A dye C293, achieving a high power conversion efficiency of 12.6% under the AM1.5G condition, in DSCs without use of any coadsorbent.
      PubDate: 2017-06-20T00:41:09.370426-05:
      DOI: 10.1002/cssc.201700916
       
  • Quantitative NMR Approach to Optimize the Formation of Chemical Building
           Blocks from Abundant Carbohydrates
    • Authors: Sebastian Meier; Samuel Elliot, Søren Tolborg, Irantzu Sadaba Zubiri, Esben Taarning
      Abstract: The future role of biomass-derived chemicals relies on the formation of diverse functional monomers in high yields from carbohydrates. Recently, it has become clear that a series of α-hydroxy acids, esters and lactones can be formed from carbohydrates in alcohols and water using tin-containing catalysts such as Sn-Beta. These compounds are potential building blocks for polyesters with additional olefin and alcohol functionalities. We employ an NMR approach to identify, quantify and optimize the formation these building blocks in the chemocatalytic transformation of abundant carbohydrates by Sn-Beta. Record yields of the target molecules can be achieved by obstructing competing reactions through solvent choice.
      PubDate: 2017-06-19T06:20:45.170886-05:
      DOI: 10.1002/cssc.201700587
       
  • Direct Electro-oxidation of Dimethyl Ether on Pt-Cu NanoChains
    • Authors: Bar Gavriel; Ronit Sharabi, Lior Elbaz
      Abstract: In this work, new catalyst for the direct electro-oxidation of dimethyl ether (DME) was synthesized and studied using an array of techniques. One of the most prominent catalysts for this reaction, platinum copper alloy (PtCu), was synthesized in an easy and low cost approach. Structural characterizations such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and elemental analysis revealed that the synthesized PtCu nanoparticles (3 nm on average), formed homogeneous NanoChains without aggregation of metallic platinum or copper. The catalyst's activity towards electro-oxidation of DME was tested using cyclic - voltammetry (CV) and in membrane-electrode assembly (MEA) in a full cell. The catalyst performance was found to be promising. Direct DME fuel cell (DDMEFC) studied in this work has relatively high energy density, of 13.5 mW cm-1 and thus shows great potential as fuel for low power fuel cells. The electrocatalysis of the DME oxidation reaction (DOR) was compared between synthesized PtCu and commercial PtRu/C and exhibited almost double the performance with the newly synthesized catalyst.
      PubDate: 2017-06-18T21:22:08.766903-05:
      DOI: 10.1002/cssc.201700702
       
  • Co-based Active Species Molecularly Immobilized on Carbon Nanotubes for
           Oxygen Reduction Reaction
    • Authors: Sujin Kim; Dawoon Jang, Joonwon Lim, Junghoon Oh, Sang Ouk Kim, Sungjin Park
      Abstract: Hybrid systems that molecule-based active species are combined with nanoscale materials may offer valuable routes to enhance the catalytic performances for electrocatalytic reactions. Development of rationally designed, cost-effective efficient catalysts for oxygen reduction reaction (ORR) is a crucial challenge for fuel cell and metal-air battery applications. In this work, we report a novel hybrid ORR catalyst material synthesized by a well-defined reaction pathway between Co-based organometallic molecules and N-doped multiwalled carbon nanotubes (MWCNT) at room temperature. The hybrid ORR catalyst shows excellent catalytic performances with an onset potential of 0.95 V (vs. RHE), superior durability and good methanol tolerance. Chemical and structural characterizations reveal that Co-based organometallic molecules maintained the original structure of Co(acetylacetonate)2 after prolonged cycles of reaction, while coordinated to heteroatoms of MWCNT. Thorough electrochemical investigation suggests that the major catalytic active site is Co-O4-NCNT.
      PubDate: 2017-06-18T21:21:58.068842-05:
      DOI: 10.1002/cssc.201701038
       
  • Sustainable Production of o-Xylene from Biomass-Derived Pinacol and
           Acrolein
    • Authors: Yancheng Hu; Ning Li, Guangyi Li, Aiqin Wang, Yu Cong, Xiaodong Wang, Tao Zhang
      Abstract: o-Xylene (OX) is a large-volume commodity chemical that is conventionally produced from fossil fuels. Herein, we report an efficient and sustainable two-step route to OX from biomass-derived pinacol and acrolein. In the first step, the phosphotungstic acid (HPW) catalyzed pinacol dehydration in 1-ethyl-3-methylimidazolium chloride ([Emim]Cl) selectively afforded 2,3-dimethylbutadiene. The high selectivity of this reaction can be ascribed to the H-bonding interaction between Cl- and the hydroxyl group of pinacol. Besides, the stabilization of the carbocation intermediate by the surrounding anion Cl- may be another reason for the high selectivity. Notably, the good reusability of the HPW/[Emim]Cl system can reduce the waste output and production cost. In the second step, OX was selectively produced by the D-A reaction of 2,3-dimethylbutadiene and acrolein, followed by the Pd/C-catalyzed decarbonylation/aromatization cascade in a one-pot fashion. The sustainable two-step process could efficiently produce renewable OX in 79% overall yield. Analogously, biomass-derived crotonaldehyde and pinacol can also serve as the feedstocks for the production of 1,2,4-trimethylbenzene.
      PubDate: 2017-06-16T04:20:21.73826-05:0
      DOI: 10.1002/cssc.201700823
       
  • Sustainable separations of C4 hydrocarbons using microporous materials
    • Authors: Stefania Tanase-Grecea; Mascha Gehre, Zhiyong Guo, Gadi Rothenberg
      Abstract: Petrochemical refineries must separate hydrocarbons mixtures on a large scale for the production of fuels and chemicals. Most often, these hydrocarbons are separated by distillation, which is extremely energy-intensive. This high energy cost can be mitigated by developing materials that can enable efficient adsorptive separation. In this critical review, we first outline the principles of adsorptive separation. We then examine the case for C4 separations using zeolites and metal-organic frameworks (MOFs). By analysing both experimental and theoretical studies, we outline the challenges and opportunities in C4 separation, with a focus on the separation mechanisms and structure-selectivity correlations. Zeolites are commonly used as adsorbents, and in some cases can separate C4 mixtures well. The pore sizes of 8-membered-ring zeolites, for example, are in the order of the kinetic diameters of C4 isomers. Although zeolites have the advantage of a rigid and highly stable structure, this is often difficult to functionalize. MOFs are attractive candidates for hydrocarbon separation because their pores can be tailored to optimize the adsorbate-adsorbent interactions. MOF-5 and ZIF-7 show promising results in separating all C4 isomers, but breakthrough experiments under industrial conditions are needed to confirm these results. Moreover, the flexibility of the MOF structures could hamper their application under industrial conditions. All in all, adsorptive separation is a promising viable alternative, and it is likely to play an increasingly important role in tomorrow's refineries.
      PubDate: 2017-06-15T21:20:27.077112-05:
      DOI: 10.1002/cssc.201700657
       
  • Novel solid state lithium conductors for lithium metal batteries based on
           electrospun nanofibers and plastic crystal composites
    • Authors: Yundong Zhou; Xiaoen Wang, Haijin Zhu, Masahiro Yoshizawa-Fujita, Yukari Miyachi, Michel Armand, Maria Forsyth, George W. Greene, Jennifer M. Pringle, Patrick Howlett
      Abstract: Organic ionic plastic crystals (OIPCs) are a class of solid-state electrolyte with good thermal stability, non-flammability, non-volatility and good electrochemical stability. When prepared in a composite with electrospun polyvinylidene fluoride (PVdF) nanofibers, a 1:1 mixture of the OIPC N-ethyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide and LiFSI produced a free-standing, robust solid state electrolyte. These high concentration Li-containing electrolyte membranes had a transference number of 0.37 (± 0.02) and supported stable lithium symmetric-cell cycling at a current density of 0.13 mA cm-2. The effects of PVdF incorporation in the Li-containing plastic crystal were investigated for different ratios of PVdF and [Li][FSI]/[C2mpyr][FSI]. Li LiNi1/3Co1/3Mn1/3O2 cells were also prepared and cycled at ambient temperature and displayed good rate performance and stability.
      PubDate: 2017-06-15T03:20:22.086337-05:
      DOI: 10.1002/cssc.201700691
       
  • Self-assembled dendritic Pt nanostructure with high-index facets as highly
           active and durable electrocatalyst for oxygen reduction
    • Authors: Youngjin Jang; Kwang-Hyun Choi, Dong Young Chung, Ji Eun Lee, Namgee Jung, Yung-Eun Sung
      Abstract: The durability issues of Pt catalyst should be resolved for the commercialization of proton exchange membrane fuel cells. Nanocrystal structures with high-index facets have been recently focused to solve the critical durability problem of fuel cell catalysts since Pt catalysts with high-index facets can preserve the ordered surfaces without change of the original structures. However, it is very difficult to develop the effective and practical synthetic methods for Pt-based nanostructures with high-index facets. The current study describes a designed simple one-pot synthesis of self-assembled dendritic Pt nanostructures with electrochemically active and stable high-index facets. Pt nanodendrites exhibited 2 times higher ORR activity and superior durability (only 3.0 % activity loss after 10,000 potential cycles) than a commercial Pt/C. The enhanced catalytic performance was elucidated by the formation of well-organized dendritic structures with plenty of reactive interfaces among 5 nm-sized Pt particles and the co-existence of low- and high-index facets on the particles.
      PubDate: 2017-06-14T23:20:42.438481-05:
      DOI: 10.1002/cssc.201700852
       
  • Detection of Reactive Oxygen Species in AEM Fuel Cells using in situ
           Fluorescence Spectroscopy
    • Authors: Yunzhu Zhang; Javier Parrondo, Shrihari Sankarasubramanian, Vijay Ramani
      Abstract: The objectives of this study were: 1) to confirm superoxide anion radical (O₂·¯) formation, and 2) to monitor in real-time the rate of O₂·¯ generation in an operating anion exchange membrane (AEM) fuel cell using in situ fluorescence spectroscopy. 1,3-diphenlisobenzofuran (DPBF) was used as the fluorescent molecular probe due to its selectivity and sensitivity towards O₂·¯ in alkaline media. The activation energy for the in situ generation of O₂·¯ during AEM fuel cell operation was estimated to be 18.3 kJ mol-1. The rate of in situ generation of O₂·¯ correlated well with the experimentally measured loss in AEM ion-exchange capacity and ionic conductivity attributable to oxidative degradation.
      PubDate: 2017-06-14T23:20:22.58716-05:0
      DOI: 10.1002/cssc.201700760
       
  • Mechanochemical Ring-Opening Polymerization of Lactide: Liquid-Assisted
           Grinding for the Green Synthesis of Poly(lactic acid) with High Molecular
           Weight
    • Authors: Nuri Ohn; Jihoon Shin, Sung Sik Kim, Jeung Gon Kim
      Abstract: A mechanochemical polymerization of lactide is developed using ball milling. Mechanical energy from the collisions between the balls and the vessel efficiently promoted an organic-base-mediated metal- and solvent-free solid-state polymerization. Investigations on the parameters of the ball-milling synthesis revealed that the degree of lactide ring-opening polymerization could be modulated by the ball-milling time, vibration frequency, mass of the ball media, and liquid-assisted grinding. Especially, liquid-assisted grinding was found to be an important factor for achieving a high degree of mechanochemical polymerization. While polymer-chain scission from the strong collision energy prevented a mechanical-force-driven high-molecular-weight polymer synthesis, the addition of only a small amount of liquid provided a sufficient energy dissipation. Thus, poly(lactic acid) with a molecular weight over 1 x 10^5 g/mol was successfully obtained by the green mechanochemical approach.
      PubDate: 2017-06-14T09:21:16.855448-05:
      DOI: 10.1002/cssc.201700873
       
  • Copper-Catalyzed Oxidative Dehydrogenative C(sp3)-H Bond Amination of
           (Cyclo)Alkanes using NH-Free Heterocycles as Amine Sources
    • Authors: Chang-Sheng Wang; Xiao-Feng Wu, Pierre H Dixneuf, Jean-Francois Soule
      Abstract: A copper-catalyzed oxidative C(sp3)-H/N-H coupling of NH-heterocycles with affordable (cyclo)alkanes was developed. This protocol involved C(sp3)-N bond formation via a radical pathway generated by a homolytic cleavage of di-tert-butyl peroxide and trapping of the radical(s) by copper catalysts. The reaction tolerated a series of functional groups, such as bromo, fluoro, ester, ketone, nitrile, methyl and methoxy. NH-free indoles, pyroles, pyrazoles, indazoles and benzotriazoles have been successfully N-alkylated.
      PubDate: 2017-06-14T04:20:26.762557-05:
      DOI: 10.1002/cssc.201700783
       
  • Enhanced Interfacial Charge Transfer on WO3 Photoanode by Molecular
           Iridium Catalyst
    • Authors: Haili Tong; Yi Jiang, Qian Zhang, Jialing Li, Wenchao Jiang, Donghui Zhang, Na Li, Lixin Xia
      Abstract: The rational design of active photoanodes for photoelectrochemical (PEC) water splitting is crucial for future applications in sustainable energy conversion. A combination of catalysts with photoelectrodes is generally required to improve surface kinetics and suppress surface recombination. In this study, we present an iridium complex (Ir-PO3H2) modified WO3 photoanode (WO3+Ir-PO3H2) for PEC water oxidation. When the Ir-based molecular catalyst (Ir-PO3H2) is anchored to a WO3 electrode, the photoanode shows a significant improvement both in photocurrent and faradaic efficiency compared to bare WO3. Under simulated sunlight illumination (AM 1.5G, 100 m Wcm−2) with an applied bias of 1.23 V vs. RHE, the photoanode exhibits a photocurrent of 1.16 mA cm−2 in acidic conditions, which is double that of bare WO3. The faradaic efficiency is promoted from 56% to 95%. Kinetic studies reveal that Ir-PO3H2 exhibits a different interfacial charge transfer mechanism on the WO3 photoanode for PEC water oxidation compared to iridium oxide (IrOx). Ir-PO3H2, as a water oxidation catalyst, can accelerate the surface charge transfer through rapid surface kinetics.
      PubDate: 2017-06-14T03:22:49.680737-05:
      DOI: 10.1002/cssc.201700721
       
  • Oxygen Vacancy Engineering of Co3O4 Nanocrystals via Constructing Coupled
           Interface with Metal Supports for Promoting Water Oxidation in Neutral
           Electrolyte
    • Authors: Jun-Jun Zhang; Hong-Hui Wang, Tian-Jian Zhao, Ke-Xin Zhang, Xiao Wei, Xin-Hao Li, Shin-Ichi Hirano, Jie-Sheng Chen
      Abstract: Oxygen vacancies could help to capture oxygen-containing species and act as active centers for oxygen evolution reaction (OER). Unfortunately, effective methods for generating a rich amount of oxygen vacancies on the surface of various nanocatalysts are rather limited. In this work, we described an effective way to generate oxygen vacancy-rich surface of transition metal oxides, exemplified with Co3O4 here, simply by constructing highly coupled interface of ultra-fine Co3O4 nanocrystals and metallic Ti. Impressively, the amounts of oxygen vacancy on the surface of Ti@Co3O4 far surpassed the reported values of the Co3O4 modified even under highly critical conditions. The Ti@Co3O4 electrode could provide a current density of 23 mA cm-2 at an OER overpotential of 570 mV, low Tafel slope and excellent durability in neutral medium. Due to the formation of a large amount of oxygen vacancies as the active centers for OER on the surface, the TOF value of the Ti@Co3O4 electrode was optimized to be 3238 h-1 at an OER overpotential of 570 mV, which is 380 times of that of the state-of-the-art non-noble nanocatalysts in the literature.
      PubDate: 2017-06-14T02:20:34.050457-05:
      DOI: 10.1002/cssc.201700779
       
  • Recent Advances in Bismuth Based Nanomaterials for Photoelectrochemical
           Water Splitting
    • Authors: Swhetha S M Bhat; Ho Won Jang
      Abstract: In recent years bismuth based nanomaterials are drawing considerable interest as potential candidates for photoelectrochemical (PEC) water splitting due to their narrow band gap, nontoxicity and low cost. The unique electronic structure with well dispersed valance band comprising of Bi 6s and O 2p orbital in the bismuth based materials offers suitable band gap to harvest visible light. This review presents the significant advancements in exploiting bismuth based materials for solar water splitting. An overview of different strategies employed and new ideas adopted to improve the PEC performance are discussed for these materials. Morphology control, construction of heterojunctions, doping and co-catalysts loading are the several approaches implemented to improve the efficiency of the solar water splitting. The key issues are identified and guidelines are suggested to rationalize the design of efficient bismuth based materials for sunlight driven water splitting.
      PubDate: 2017-06-13T22:20:49.128141-05:
      DOI: 10.1002/cssc.201700633
       
  • Stable Organic Radicals in Lignin; A Review
    • Authors: Dimitris Argyropoulos; Shradha S Patil
      Abstract: Lignin and the quest for the origin of stable organic radicals in it have seen numerous developments. Although there have been various speculations over the years on the formation of these stable radicals, researchers have not been to arrive at a solid, unequivocal hypothesis that applies to all treatments and types of lignin. The extreme complexity of lignin and its highly aromatic, crosslinked, branched and rigid structure has made such efforts rather cumbersome. Since the early fifties, researchers in this field have dedicated their efforts to establish methods for the detection and determination of spin content, theoretical simulations, and reactions on model compounds and spin trapping studies. While a significant amount of published research is available on lignin or its model compounds and the reactive intermediates involved during various chemical treatments (pulping, bleaching, extractions, chemical modifications, etc.) the literature provides a limited view on the origin, nature, and stability of such radicals. Consequently, this review is focused on examining the origin of such species in lignin, factors affecting their presence, reactions involved in their formation, and methods for their detection.
      PubDate: 2017-06-12T07:15:20.852255-05:
      DOI: 10.1002/cssc.201700869
       
  • Influence of sulfuric acid on the performance of ruthenium-based catalysts
           in the liquid-phase hydrogenation of levulinic acid to γ-valerolactone
    • Authors: Jamal Ftouni; Homer Genuino, Ara Munoz-Murillo, Pieter Bruijnincx, Bert Weckhuysen
      Abstract: The presence of biogenic or process-derived impurities poses a major problem on the efficient catalytic hydrogenation of biomass-derived levulinic acid to γ-valerolactone, hence, studies on their influence on catalyst stability are now required. Here, we investigate the influence of sulfuric acid as feed impurity on the performance of Ru-based heterogeneous catalysts, including Ru/ZrO2 and mono- and bimetallic Ru-on-carbon catalysts in dioxane as solvent. The carbon-supported Ru catalysts proved to be very sensitive to minor amounts of this impurity. In stark contrast, Ru/ZrO2 showed a remarkable stability in the presence of the same impurity, which is attributed to the sulfate ion adsorption capacity of the support. Preferential sulfate adsorption onto the surface of ZrO2 effectively protects the Ru active phase from deactivation by sulfur poisoning. A simple catalyst regeneration strategy proved to be effective in removing adsorbed impurities, allowing for efficient catalyst recycling.
      PubDate: 2017-06-11T21:20:55.319737-05:
      DOI: 10.1002/cssc.201700768
       
  • An Efficient and Versatile Catalyst for Carbon Dioxide Fixation into
           Cyclic Carbonates
    • Authors: Antonio Otero; Javier Martinez, Juan Fernandez-Baeza, Luis F Sanchez-Barba, Jose A Castro-Osma, Agustin Lara-Sanchez
      Abstract: A new heteroscorpionate lanthanum complex has shown exceptional catalytic activity for the synthesis of cyclic carbonates from epoxides and carbon dioxide. The new catalyst system also promotes the reaction of bio-based epoxides to give an important class of bis(cyclic carbonates) that can be further used for the production of bio-derived non-isocyanate polyurethanes. The catalytic process requires low catalyst loading and mild reaction conditions for the synthesis of a wide range of cyclic carbonates.
      PubDate: 2017-06-09T10:55:05.886397-05:
      DOI: 10.1002/cssc.201700898
       
  • Defect chemistry, electrical properties and evaluation of new ox-ides
           Sr2CoNb1-xTixO6-δ (0≤x≤1) as cathode materials for Solid Oxide Fuel
           Cells
    • Authors: M. Teresa Azcondo; Mercedes Yuste, Juan Carlos Perez Flores, Daniel Muñoz Gil, Susana García Martín, Alvaro Muñoz Noval, Inés Puente Orench, Flaviano García Alvarado, Ulises Amador
      Abstract: : The perovskite series Sr2CoNb1-xTixO6-δ (0≤x≤1) is investigated in the full compositional range to assess its potential as cathode material for solid state fuel cell (SOFC). The variation of transport properties and thus, the area specific resistances (ASR) are explained by a detailed investigation of the defect chemistry. Increasing titanium content from x=0 to x=1 produces both oxidation of Co3+ to Co4+ (from 0% up to 40%) and oxygen vacancies (from 6.0 to 5.7 oxygen atom/formula unit) though each charge compensation mechanism predominates in different compositional ranges. Neutron diffraction reveals that samples with high Ti-contents lose a significant amount of oxygen on heating above 600K. Oxygen is partially recovered on cooling since the oxygen release and uptake show noticeably different kinetics. The complex defect chemistry of these compounds, together with the compositional changes upon heating-cooling cycles and atmospheres produce, a complicated behavior of electrical conductivity. Cathodes containing Sr2CoTiO6-δ display low ASR values, 0,13 Ωcm2 at 973 K, comparable to those of the best compounds reported so far, being a very promising cathode material for SOFC.
      PubDate: 2017-06-08T05:20:25.770706-05:
      DOI: 10.1002/cssc.201700648
       
  • Isohexide Dinitriles: a versatile family of renewable platform chemicals
    • Authors: Jing Wu; Shanmugam Thiyagarajan, Célia Fonseca Guerra, Pieter Eduard, Martin Lutz, Bart A. J. Noordover, Cor E. Koning, Daan S. van Es
      Abstract: New 2/5 1-carbon extended isohexide building blocks are now synthetically accessible by a convenient, selective base-catalyzed epimerization of the corresponding dinitriles. Kinetic experiments using the strong organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) show that all three possible isohexide dinitrile isomers are in a dynamic equilibrium. An epimerization mechanism is proposed, based on DFT calculations. Structural identification of all three possible isomers is based on NMR analysis as well as single crystal x-ray crystallography. DFT calculations confirmed that the observed crystal structures are indeed the lowest energy conformers of these isohexide derivatives.
      PubDate: 2017-06-07T05:20:38.270165-05:
      DOI: 10.1002/cssc.201700617
       
  • Greening the processes in MOFs synthesis and MOFs-involved sustainable
           catalysis
    • Authors: Junying Chen; Kui Shen, Yingwei Li
      Abstract: Given the shortage of sustainable resources and the arising serious environment impact in recent decades, the demand for clean technologies and sustainable sources is of great interest to worldwide researchers. As we look into the fields of energy saving and environment cleaning, the key point is the development of efficient catalysts, not only in the way of facile synthesis methods, but also the utilization of such catalysts in benign manners. This work reviews the dedication of metal-organic frameworks (MOFs) and MOF-based materials to these fields. The definition of MOFs and MOF-based materials will be primarily introduced followed by the brief description of the characterization and stability of MOF related materials under applied conditions. The greening processes of MOFs synthesis will be illustrated then, catalogued by benign solvents and conditions, and green precursors of MOFs. Further, the suitable application in sustainable catalysis will be summarized, focusing on several typical atom economic reactions, e.g., the direct introduction of H2 and O2, and C-C bond formation. The approaches towards reducing CO2 emitting by MOF-based catalysts will be described with special emphasis on CO2 fixation and CO2 reduction. In addition, driven by the explosive growth of energy consumption from last century, researches on biomass, which are renewable alternatives to fossil fuels and sustainable carbon feedstock for chemicals production, have been exploited. The advanced progress of biomass-related transformation will be illustrated. The fundamental insight into the nature of MOFs-based materials as constitutionally easily-recoverable heterogeneous catalysts and as supports to inducting varied active sites is thoroughly discussed. Finally, the facing challenges of the development in this field and the outlook for future research will be presented.
      PubDate: 2017-06-06T22:20:36.497952-05:
      DOI: 10.1002/cssc.201700748
       
  • Ionic Liquid-Assisted Microwave Synthesis of Solid Solutions of Perovskite
           Sr1-xBaxSnO3 for Photocatalytic Applications
    • Authors: Anja Verena Mudring; Tarek Alammar, Igor Slowing, Jim Anderegg
      Abstract: For the first time nanocrystal perovskite Sr1-xBaxSnO3 photocatalysts were prepared by means of microwave synthesis in an ionic liquid (IL) and subsequent heat-treatment. The influence of the Sr/Ba substitution on the structure, crystallization, morphology and, in the end, the photocatalytic efficiency of SrSnO3 was investigated. Based on the structure characterization using X-ray diffraction, with increasing Ba content in the lattice of SrSnO3 a symmetry increase from the orthorhombic perovskite structure for SrSnO3 to the cubic for BaSnO3 was observed. Analysis of the sample morphology using SEM reveals that the Sr1-xBaxSnO3 samples favor the formation of nanorods (500 nm - 5 μm in diameter and several micrometers in length). The band gap decreases with increasing Ba2+ content from 3.85 eV to 3.19 eV. Furthermore, the photocatalytic properties were evaluated by the hydroxylation of terephthalic acid (TA). The order of the activities of TA hydroxylation was Sr0.8Ba0.2SnO3> SrSnO3> BaSnO3> Sr0.6Ba0.4SnO3> Sr0.2Ba0.8SnO3. The highest photocatalytic activity was observed for Sr0.8Ba0.2SnO3 which can be attributed to the synergistic impacts of the modification of crystal structure and morphology, the relatively large surface area associated with the small crystallite size and suitable band gap size as well as band edge position.
      PubDate: 2017-06-06T22:20:33.920251-05:
      DOI: 10.1002/cssc.201700615
       
  • Boosting the supercapacitance of nitrogen-doped carbon by tuning surface
           functionalities
    • Authors: Jasper Biemolt; Ilse M. Denekamp, Thierry K. Slot, Gadi Rothenberg, David Eisenberg
      Abstract: We report that the specific capacitance of a highly porous, nitrogen-doped carbon is nearly tripled by orthogonal optimization of microstructure and surface chemistry. First, the carbons' hierarchical pore structure and specific surface area were tweaked by controlling the temperature and sequence of thermal treatments. The best process (pyrolysis at 900 °C, washing, and a second annealing at 1000 °C) yielded carbons with a specific capacitance of 117 F/g - nearly double that of a carbon made by a typical, single-step synthesis at 700 °C. Following the structural optimization, the surface chemistry of the carbons was enriched by applying an oxidation routine based on nitric and sulfuric acids in 1:4 ratio, at two different treatment temperatures (0 °C and 20 °C) and along different treatment times. The optimal treatment times are 4 h at 0 °C and only 1 h at 20 °C. Overall, specific capacitance nearly tripled relative to the original carbon, reaching to 168 F/g. The inherent nitrogen doping of the carbon comes into interplay with the acid-induced surface functionalization, creating a mixture of oxygen- and nitrogen-oxygen functionalities. The evolution of surface chemistry was carefully followed by X-ray photoelectron spectroscopy and by N2 sorption porometry, revealing stepwise surface functionalization and simultaneous carbon etching. Overall, these processes are responsible for the peak-shaped capacitance trends in the carbons.
      PubDate: 2017-06-06T10:15:21.602775-05:
      DOI: 10.1002/cssc.201700902
       
  • Ni@Ni(OH)2 Core-Shell Particles Partially Covering Silicon Photoanode for
           
    • Authors: Shicheng Yan; Zhe Xu, Zhan Shi, Lang Pei, Zhengbin Gu, Zhigang Zou
      Abstract: One main barrier for enhancing solar energy conversion by photoelectrochemical (PEC) water splitting devices is the charge separation and transport efficiency at the interface region of the photoanode and electrolyte. Here, we electrodeposited the core-shell structured Ni@Ni(OH)2 nanoparticles on the surface of n-type Si photoanode with island distribution. We found that the Schottky barrier between Ni and Si is sensitive to the thickness of Ni(OH)2 shell. The photovoltage output of the photoanode increases with increasing the thickness of Ni(OH)2 shell, closely associating with the interaction between Ni and Ni(OH)2 that depends on the electrolyte screening effect and p-type feature of Ni(OH)2 layer. As a result, the Ni@Ni(OH)2 core-shell nanoparticles with appropriate shell thickness coupling with n-Si photoanode can promote the separation of photogenerated carriers and improve the charge injection efficiency to nearly 100%, thus affording a onset potential of 1.03 VRHE and saturated current density of 36.4 mA·cm-2. The proposed interface manipulation method of varying the thickness of the electrocatalyst in our study may open a new route to development of high-performance PEC devices.
      PubDate: 2017-06-06T08:21:26.983505-05:
      DOI: 10.1002/cssc.201700825
       
  • Intensified biobutanol recovery using zeolites with complementary
           selectivity
    • Authors: Stijn Van der Perre; Pierre Gelin, Benjamin Claessens, Ana Martin-Calvo, Julien Cousin Saint Remi, Tim Duerinck, Gino V. Baron, Miguel Palomino, Ledys Y. Sanchez, Susana Valencia, Jin Shang, Ranjeet Singh, Paul A. Webley, Fernando Rey, Joeri Denayer
      Abstract: A vapor phase adsorptive recovery process is proposed as an alternative way to isolate biobutanol from acetone-butanol-ethanol (ABE) fermentation media, offering several advantages compared to liquid phase separation. The effect of water, which is still present in large quantities in vapor phase, on the adsorption of the organics could be minimized by using hydrophobic zeolites. Shape selective all-silica zeolites CHA and LTA were prepared and evaluated via single component isotherms and breakthrough experiments. These zeolites show an opposite selectivity; adsorption of ethanol was favorable on all-silica CHA, while the LTA topology had clear preference for butanol. The molecular sieving properties of both zeolites allowed to easily eliminate acetone from the mixture. The molecular interaction mechanisms were studied by density functional theory (DFT) simulations. Effect of mixture composition, humidity and total pressure of the vapor stream on the selectivity and separation behavior was investigated. Desorption profiles were studied to maximize butanol purity and recovery. The combination of LTA with CHA type zeolites (Si-CHA or SAPO-34) in sequential adsorption columns with alternating adsorption and desorption steps allows to obtain butanol in unpreceded purity and recovery. A butanol purity of 99.7 mole% could be obtained at nearly complete butanol recovery, demonstrating the effectiveness of this technique for biobutanol separation processes.
      PubDate: 2017-06-06T06:15:20.378238-05:
      DOI: 10.1002/cssc.201700667
       
  • High Performance Ruthenium Sensitizers Containing Imidazoliums as
           Counterions for the Efficient Dye-Sensitization in Water
    • Authors: Xiaoyu Li; Shiqing Li, Ge Gao, Di Wu, Jingbo Lan, Ruilin Wang, Jingsong You
      Abstract: A new type of water-soluble ruthenium sensitizers containing imidazoliums as counterions, coded [DMPI]2-Ru and [DMHI]2-Ru, has been developed, which can be efficiently adsorbed on TiO2 in aqueous solution. Owing to the good thermal stability of imidazolium, [DMPI]2-Ru adsorbed on TiO2 possesses a higher decomposition temperature than N719. When using organic solvent-based I−/I3− electrolytes, the solar cell based on [DMPI]2-Ru-sensitized TiO2 in water shows a high power conversion efficiency (PCE) up to 10.2%, which is higher than that of N719 (9.9%) under the common condition of the dye-sensitization process in organic solvent. In comparison with [DMPI]2-Ru, [DMHI]2-Ru with a relatively poorer water-solubility shows a smaller dye adsorption amount on TiO2, thus giving a lower PCE of 9.4%. From the viewpoint of safety and environmental impact, the fabrication of DSSCs by fully using water as solvent is undoubtedly a more ideal strategy. Although the [DMPI]2-Ru-based device fabricated by using water as the solvent of both the dye-sensitization process and electrolytes gives a relatively low efficiency, it provides a promising approach for the practical application of DSSCs.
      PubDate: 2017-06-04T21:20:41.193971-05:
      DOI: 10.1002/cssc.201700579
       
  • Additives Based on Green Chemistry for Recyclable Epoxy Matrice
    • Authors: Martin Lahn Henriksen; Jens Bomholdt Ravnsbæk, Morten Bjerring, Thomas Vosegaard, Kim Daasbjerg, Mogens Hinge
      Abstract: Epoxy based thermosets are one of the most popular material matrices in many industries and significant environmental benefits can be obtained by development of a recyclable epoxy variant of this widely utilized material. This paper demonstrates that addition of a biobased additive to a commercial epoxy system leads to a crosslinked material that can be fractionated under mild and environmentally benign conditions. The novel material has been analyzed by FT-IR and solid state NMR. Furthermore, modified epoxy matrices with low additive concentrations are demonstrated to have similar mechanical and thermal properties when benchmarked against the commercial available epoxy matrix. Thus, additives and fractionation based on green chemistry has been demonstrated and a recyclable epoxy matrix has been developed.
      PubDate: 2017-05-30T12:20:23.309149-05:
      DOI: 10.1002/cssc.201700712
       
  • Bottom-up construction of TEMPO built-in porous organic frameworks as a
           cathode for lithium-sulphur batteries
    • Authors: Baolong Zhou; Xiang Hu, Guang Zeng, Shiwu Li, Zhenhai Wen, long chen
      Abstract: Two redox-active radical (TEMPO) built-in porous organic frameworks (POFs), which feature hierarchical porous structures, were synthesized via a facile bottom-up strategy and were studied as cathode materials for lithium-sulphur (Li-S) batteries. The sulphur loading in these two POFs can reach up to 61% benefitting from their large pore volume. For the existence of highly densed docking sites of TEMPO, sulphur could be covalently restrained within the porous networks and efficiently inhibited the shuttle effect, therefore significantly improving the cycling performance. The TPE-TEMPO-POF-S composites deliver a capacity beyond 470 mAh g-1 after 200 cycles with a coulombic efficiency of around 100% at the current rate of 0.1 C. Furthermore, the sulphur embedded TEMPO-POFs show excellent rate capability with limited capacity loss at varied rate from 0.1 to 1C.
      PubDate: 2017-05-29T22:20:25.219543-05:
      DOI: 10.1002/cssc.201700749
       
  • Ionic Liquid/Metal Organic Framework Composites: From Synthesis to
           Applications
    • Authors: Pelin Kinik; Alper Uzun, Seda Keskin
      Abstract: Metal organic frameworks (MOFs) have been widely studied in different applications since their first synthesis due to their fascinating properties such as large surface areas, high porosities, tunable pore sizes, acceptable thermal and chemical stabilities. Ionic liquids (ILs) have been recently incorporated into the pores of MOFs as cavity occupants to change the physicochemical properties and gas affinities of MOFs. Several recent studies have shown that IL-incorporated MOF composites show superior performances compared to pristine MOFs in various fields such as gas storage, adsorption and membrane-based gas separation, catalysis and ionic conductivity. In this review, we address the recent advances in syntheses of IL-incorporated MOFs and provide a comprehensive overview on their applications. Opportunities and challenges of using IL/MOF composites in many applications were reviewed and requirements for the utilizations of these composite materials in real industrial processes were discussed to define the future directions in this field.
      PubDate: 2017-05-29T04:27:51.756365-05:
      DOI: 10.1002/cssc.201700716
       
  • High Efficiency Perovskite Solar Cell Based on Poly (3-hexylthiophene)
           (P3HT): The Influence of P3HT Molecular Weight and Mesoscopic Scaffold
           Layer
    • Authors: Narges Yaghoobi Nia; Fabio Matteocci, Lucio Cina, Aldo Di Carlo
      Abstract: In this work, we investigated the effect of the Molecular Weight (MW) of Poly 3-hexylthiophene (P3HT) hole transporting material on the performance of perovskite solar cells (PSCs). We found that, by increasing the MW, the photovoltaic performances of the cells are enhanced leading to an improvement of the overall efficiency. P3HT-based PSCs with a MW of 124 kDa can achieve an overall average efficiency of 16.2%, double with respect to the ones with a MW of 44 kDa. Opposite to the Spiro-OMeTAD-based PSCs, photovoltaic parameters of the P3HT-based devices are enhanced by increasing the mesoporous TiO2 layer thickness from 250 nm to 500 nm. Moreover, for a Titania scaffold layer thickness of 500 nm the efficiency of P3HT-based PSCs with high MW is larger than the Spiro-OMeTAD based PSCs with the same scaffold layerthickness. Recombination reactions of the devices are also investigated by voltage decay and electrochemical impedance spectroscopy. We found that the relation between P3HT MW and cell performance is related to the reduction of charge recombination and to the increase of the P3HT light absorption by increasing the MW.
      PubDate: 2017-05-28T21:20:31.210613-05:
      DOI: 10.1002/cssc.201700635
       
  • Mapping the free energy of lithium solvation in the protic ionic liquid
           Ethylammonuim Nitrate: A metadynamics study
    • Authors: Ali Kachmar; Marcelo Carignano, Teodoro Laino, Marcella Iannuzzi, Jürg Hutter
      Abstract: The understanding of lithium solvation and transport in ionic liquids is important due to the possible applications in electrochemical devices. Using first principles simulations aided with the metadynamics approach we study the free energy landscape for lithium at infinite dilution conditions in ethylammonium nitrate, a protic ionic liquid. We analyze the local structure of the liquid around the lithium cation and find a quantitative picture in agreement with experimental findings. Our simulations show that the lowest two free energy minima correspond to conformations with the lithium solvated either by 3 or 4 nitrates ions with a transition barrier between them of 0.2 eV. Other less probable conformations having a different solvation pattern are also investigated.
      PubDate: 2017-05-26T00:25:29.763862-05:
      DOI: 10.1002/cssc.201700510
       
  • Metal-organic Compound Branched MoS2 for Achieving High Performance
           Perovskite Solar cells
    • Authors: Ruina Dai; Yangyang Wang, Jie Wang, Xianyu Deng
      Abstract: MoS2 as a graphene-like 2D material shows a large potential to replace even overcome graphene in various important applications due to its perfect properties of electrical, optical, frictional, and tunable band gap. However, low solubility in the most of common solvents makes it difficult to prepare via a simple solution process. Here we introduce a metalorganic compound to modify MoS2. Phenyl acetylene silver (PAS) functionalized MoS2 compound is easily dispersed in the solvent of DMF and water. A conductive polymer PEDOT: PSS blend with the MoS2 leads to a significant enhancement of the performance of planar heterojunction perovskite solar cells. The solar cells have a high power conversion efficiency of 16.47% as well as largely increased stability. This provides a feasible method on large-scale yield of the MoS2 for wide applications in various electric devices.
      PubDate: 2017-05-25T21:20:28.148643-05:
      DOI: 10.1002/cssc.201700603
       
  • Brownmillerite-type Ca2FeCoO5 as a Practicable Oxygen Evolution Reaction
           Catalyst
    • Authors: Etsushi Tsuji; Teruki Motohashi, Hiroyuki Noda, Damian Kowalski, Yoshitaka Aoki, Hajime Tanida, Junji Niikura, Yukinori Koyama, Masahiro Mori, Hajime Arai, Tsutomu Ioroi, Naoko Fujiwara, Yoshiharu Uchimoto, Zempachi Ogumi, Hiroki Habazaki
      Abstract: Here, we report remarkable oxygen evolution reaction (OER) catalytic activity of brownmillerite (BM)-type Ca2FeCoO5. The OER activity of this oxide is comparable to or beyond those of the state-of-the-art perovskite (PV)-catalyst Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) and a precious-metal catalyst RuO2, emphasizing the importance of the characteristic BM structure with multiple coordination environments of transition metal (TM) species. Also, Ca2FeCoO5 is obviously advantageous in terms of expense/laboriousness of the material synthesis. These facts make this oxide a promising OER catalyst used in many energy conversion technologies such as metal-air secondary batteries and hydrogen production from electrochemical/photocatalytic water splitting.
      PubDate: 2017-05-25T00:20:22.793569-05:
      DOI: 10.1002/cssc.201700499
       
  • Understanding the limiting factors of solvent annealed Small molecule bulk
           heterojunction organic solar cells from a chemical perspective
    • Authors: Aurelien Viterisi; Daniel Fernandez, Vijay Kumar Challuri, James william Ryan, Eugenia Martinez-Ferrero, Francesc Guispert-Guirado, Marta Martinez, Eduardo Escudero, Caterina Stenta, Lluis Francisco Marsal, Emilio Palomares
      Abstract: A detailed account on the limiting factors of solvent annealed bulk-heterojunction small molecule organic solars cell is given. This account is based on the extensive characterization of solar cell devices made from a library of five diketopyrolopyrole (DPP) donor dyes. Their chemical structure is designed in such a way as to provide insights on the energetics of solar cell active layer microstructure formation. Numerous chemical and physical properties of the active layers are assessed and interrelated such as light absorption, molecular packing in the solid state, crystal-forming properties in thin films, charge carrier mobility and charge carrier recombination kinetics. A myriad of characterization techniques are used such as UV-Vis absorption, photoluminescence, X-ray diffraction (XRD), AFM, photo-induced transient measurements which provide information on optical properties of the active layers, morphology and recombination kinetics. Consequently, a mechanism for the solvent vapour annealing-assisted formation of crystalline domains of donor molecules in the active layer is proposed, and the microstructure features are related to the J-V characteristics of the devices. According to this model, the crystalline phase in which the donor crystallize in the active layer is the key determinant in directing the formation of the microstructure.
      PubDate: 2017-05-24T10:20:27.604284-05:
      DOI: 10.1002/cssc.201700440
       
  • A strategy to enhance the efficiency of quantum dot sensitized solar cells
           by decreasing the electron recombinations with polyoxometalate/TiO2 as the
           electronic interface layer
    • Authors: Li Chen; Wei-Lin Chen, Jian-Ping Li, Jia-Bo Wang, En-Bo Wang
      Abstract: The serious electron recombination occurring in TiO2/quantum dot sensitizer/electrolyte interface is the key reason for hindering the further efficiency improvement of QDSCs. Polyoxometalate(POM) can be as electron transfer media to decreasing electron recombination of photoelectric device, which is due to the excellent oxidation reduction properties and thermostability. So in this paper, POM/TiO2 electronic interface layer prepared by a simple layer-by-layer self-assembly method is added between FTO and mesoporous TiO2 in the photoanode of the QDSCs, and their effects on the photovoltaic performance are systematically investigated. The photovoltaic experimental results and electron transmission mechanism explanation show that POM/TiO2 electronic interface layer in the QDSCs can obviously suppress the electron recombinations, increase the electron lifetime and result in smoother electron transmission. In summary, the best conversion efficiency of QDSCs with POM/TiO2 electronic interface layers are increased to 8.02%, which are improved by 25.1% compared to the QDSCs without POM/TiO2. This work firstly builds an electron transfer bridge between FTO and quantum dot sensitizer and paves the way for the further efficiency improvement of QDSCs.
      PubDate: 2017-05-23T06:21:17.858876-05:
      DOI: 10.1002/cssc.201700764
       
  • Environmentally friendly recycling of fuel cell's membrane electrode
           assembly using ionic liquids
    • Authors: Sophie Legeai; Maxime Balva, Nathalie Leclerc, Emmanuel Billy, Eric Meux
      Abstract: The platinum nanoparticles used as catalyst in Proton Exchange Membrane Fuel Cells (PEMFCs) could represent around 46 % of the total price of the cells1 for a large scale production which is one of the limitation of their commercialization. The recycling of this platinum catalyst can then be the best alternative to limit the production cost of PEMFCs. Usual recovery routes for spent catalysts containing platinum are pyro-hydrometallurgical processes in which a calcination step is followed by aqua regia treatment, generating fumes and NOx emission, respectively. An electrochemical recovery route is proposed here, more environmentally friendly, performed in "soft" temperature conditions and without any gases emission. It consists in the coupling of electrochemical leaching of platinum in chloride-based ionic liquids (ILs), followed by its electrodeposition. The leaching of platinum was studied in pure ionic liquids and in ionic liquids melts, at different temperatures and chloride contents. By modulating the composition of the ionic liquid melts, it is further possible to leach and electrodeposit the platinum from fuel cell electrodes in a single cell process, under inert or ambient atmosphere.
      PubDate: 2017-05-18T08:45:24.63433-05:0
      DOI: 10.1002/cssc.201700456
       
  • Reactive Precipitation of Anhydrous Alkali Sulfide Nanocrystals with
           Concomitant Abatement of Hydrogen Sulfide and co-Generation of Hydrogen
    • Authors: Yongan Yang; Xuemin Li, Yangzhi Zhao, Alice Brennan, Miranda McCeig, Colin A. Wolden
      Abstract: Anhydrous alkali sulfide (M2S, M = Li and Na) nanocrystals (NCs) are important materials central to the development of next generation cathodes and solid state electrolytes for advanced batteries, but not commercially available at present. This work reports an innovative method to directly synthesize M2S-NCs through alcohol-mediated reactions between alkali metals and hydrogen sulfide (H2S). In the first step, the alkali metal is complexed with alcohol in solution, forming metal alkoxide (ROM) and releasing hydrogen (H2). Next, H2S is bubbled through the ROM solution, where both chemicals are completely consumed to produce phase-pure M2S-NC precipitates and regenerate alcohol that can be recycled. The M2S-NC morphology may be tuned through choice of the alcohol and the solvent. Both synthetic steps are thermodynamically favorable (∆Gmo < -100 kJ/mol), proceeding rapidly to completion at ambient temperature with ~100% atom efficiency. The net result, H2S + 2M -> M2S + H2, makes good use of a hazardous chemical H2S and delivers two value-added products that naturally phase separate for easy recovery. This scalable approach provides an energy-efficient and environmentally-benign solution to the production of nanostructured materials required in emerging battery technologies.
      PubDate: 2017-05-16T10:45:29.314435-05:
      DOI: 10.1002/cssc.201700532
       
  • Electrochemically-driven fermentation of organic substrates with undefined
           mixed microbial cultures
    • Authors: Marianna Villano; Paola Paiano, Enza Palma, Alfredo Miccheli, Mauro Majone
      Abstract: Growing scientific interest in mixed microbial culture-based anaerobic biotechnologies for the production of value-added chemicals and fuels from waste organic residues requires a parallel focus on the development and implementation of strategies to control products distribution. This study examined the feasibility of an electro-fermentation approach, based on the introduction of a polarized (-700 mV vs. the standard hydrogen electrode) graphite electrode in the fermentation medium, to steer products distribution during the conversion of organic substrates (glucose, ethanol, and acetate supplied as single compounds or in mixtures) by undefined mixed microbial cultures. As a main result, in batch experiments the polarized electrode triggered a nearly 20-fold increase (relative to open circuit controls) in the yield of i-butyrate production (0.43±0.01 vs. 0.02±0.02 mol/ mol glucose) during the anaerobic fermentation of the ternary mixture of substrates, without adversely affecting the rate of substrate bioconversion. The observed change in the fermentative metabolism was most likely triggered by the (potentiostatic) regulation of the oxidation-reduction potential of the reaction medium rather than by the electrode serving as an electron donor.
      PubDate: 2017-05-04T07:15:37.59715-05:0
      DOI: 10.1002/cssc.201700360
       
 
 
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