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  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
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Transactions of Tianjin University
Journal Prestige (SJR): 0.166
Number of Followers: 0  
 
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ISSN (Print) 1006-4982 - ISSN (Online) 1995-8196
Published by Tianjin University Homepage  [1 journal]
  • High-Efficiency (Over 10%) Parallel Tandem Dye-Sensitized Solar Cells
           Based on Tri-Carbon Electrodes

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      Abstract: Abstract Ensuring high power conversion efficiency, partially or completely replacing Pt electrodes with inexpensive materials is one of the important development directions of dye-sensitized solar cells (DSSCs). In this work, we have developed a three-component (MWCNTs, carbon black and graphite) carbon (tri-carbon) electrode material for DSSC devices combined with the advantages of high electron transfer kinetics of MWCNTs, plentiful catalytic sites in crystal edges of carbon black and superior electrical conductivity and catalytic activity of graphite. Using a tri-carbon electrode, a Pt electrode, and two N719-sensitized photoanodes, a parallel tandem dye-sensitized solar cells are assembled obtaining a high PCE of 10.26% (Voc = 0.70 V, Jsc = 19.99 mA/cm2, FF = 73.33%). It opens up a new avenue for the development of low-cost and high-performance DSSCs.
      PubDate: 2022-05-13
       
  • Recent Advances in Lead Chemisorption for Perovskite Solar Cells

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      Abstract: Abstract Lead toxicity in perovskite materials, which have hazardous effects on the environment and the human body, has drawn considerable attention to emerging photovoltaic technology perovskite solar cells. Despite the capability of other strategies to prevent lead leakage, chemisorption is another efficient approach to block Pb leaching by employing Pb absorbents in/out of device structures. This review discusses lead toxicity and summarizes the recent research about chemisorption strategies by their functions: additives, the hole-transporting layers, interfacial modifiers, and encapsulation layers. Finally, the basic guidelines and challenges for designing novel Pb-adsorbing materials and encapsulation structures are presented.
      PubDate: 2022-05-13
       
  • Research Progress of Catalysts and Initiators for Promoting the Cracking
           of Endothermic Hydrocarbon Fuels

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      Abstract: Catalytic/initiated cracking of endothermic hydrocarbon fuels is an effective technology for cooling a hypersonic aircraft with a high Mach number (over 5). Catalysts and initiators can promote fuel cracking at low temperatures, increase fuel conversion and the heat sink capacity, and suppress coke deposition, thereby reducing waste heat. Catalysts mainly include metal oxide catalysts, noble metal catalysts and metal nanoparticles, zeolite catalysts, nanozeolite catalysts, and coating catalysts. Moreover, initiators roughly include nitrogenous compounds, oxygenated compounds, and hyperbranched polymer initiators. In this review, we aim to summarize the catalysts and initiators for cracking endothermic hydrocarbon fuels and their mechanisms for promoting cracking. This review will facilitate the development of the synthesis and exploration of catalysts and initiators.
      PubDate: 2022-05-03
       
  • Black Phosphorus/Nanocarbons Constructing a Dual-Carbon Conductive Network
           for High-Performance Sodium-Ion Batteries

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      Abstract: Black phosphorus has been recognized as a prospective candidate anode material for sodium-ion batteries (SIBs) due to its ultrahigh theoretical capacity of 2596 mA·h/g and high electric conductivity of ≈ 300 S/m. However, its large volume expansion and contraction during sodiation/desodiation lead to poor cycling stability. In this work, a BP/graphite nanoparticle/nitrogen-doped multiwalled carbon nanotubes (BP/G/CNTs) composite with a dual-carbon conductive network is successfully fabricated as a promising anode material for SIBs through a simple two-step mechanical milling process. The unique structure can mitigate the effect of volume changes and provide additional electron conduction pathways during cycles. Furthermore, the formation of P–O–C bonds helps maintain the intimate connection between phosphorus and carbon, thereby improving the cycling and rate performance. As a result, the BP/G/CNTs composite delivers a high initial Coulombic efficiency (89.6%) and a high specific capacity for SIBs (1791.3 mA·h/g after 100 cycles at 519.2 mA/g and 1665.2 mA·h/g after 100 cycles at 1298 mA/g). Based on these results, the integrated strategy of one- and two-dimensional carbon materials can guide other anode materials for SIBs.
      PubDate: 2022-04-01
       
  • One-Step Hydrothermal Synthesis of a CoTe@rGO Electrode Material for
           Supercapacitors

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      Abstract: CoTe@reduced graphene oxide (CoTe@rGO) electrode materials for supercapacitors were prepared by a one-step hydrothermal method in this paper. Compared with that of pure CoTe, the electrochemical performance of CoTe@rGO was significantly improved. The results showed that the optimal CoTe@rGO electrode material has a remarkably high specific capacitance of 810.6 F/g at a current density of 1 A/g. At 5 A/g, the synthesized material retained 77.2% of its initial capacitance even after 5000 charge/discharge cycles, thereby demonstrating good cycling stability. Moreover, even at a high current density of 20 A/g, the composite electrode retained 79.0% of its specific capacitance at 1 A/g, thus confirming its excellent rate performance. An asymmetric supercapacitor (ASC) with a wider potential window and higher energy density was assembled by using 3 M KOH as the electrolyte, the CoTe@rGO electrode as the positive electrode, and active carbon as the negative electrode. The operating voltage of the supercapacitor could be increased to 1.6 V, and its specific capacitance could reach 112.6 F/g at 1 A/g. The specific capacitance retention rate of the fabricated supercapacitor after 5000 charge/discharge cycles at 5 A/g was 87.1%, which confirms its excellent cycling stability. In addition, the ASC revealed a high energy density of 40.04 W·h/kg at a power density of 799.91 W/kg and a high power density of 4004.93 W/kg at an energy density of 33.43 W·h/kg. These results collectively show that CoTe@rGO materials have broad application prospects.
      PubDate: 2022-04-01
       
  • Fabrication of Ce-ReS2 by Molten Salt for Electrochemical Hydrogen
           Evolution

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      Abstract: Renewable and economical generation of hydrogen via electrochemical methods shows great potential in addressing the energy crisis. In this study, an emerging molten salt method was adopted for the synthesis of a cerium-modified rhenium disulfide nanosheet for electrical hydrogen evolution reactions. The prepared 1% Ce-doped rhenium disulfide (ReS2) sample showed promoted hydrogen evolution performance in both acid and alkaline electrolytes compared to bare ReS2. Generating of abundant defects in ReS2 exposed more reaction active sites. Moreover, adding cerium accelerated the hydrogen evolution dynamics. Hopefully, this work will offer new insight into developing ReS2-based electrocatalysts for hydrogen evolution reactions.
      PubDate: 2022-03-29
       
  • Performance Analysis of Compound Parabolic Concentration Photothermal and
           Photoelectricity Device for Soil Heating in Facility Agriculture

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      Abstract: It is difficult for solanum crops to grow continuously during winter in severe cold regions. Thus, a soil heating system for facility agriculture based on solar concentration technology was proposed, and a novel compound parabolic concentration photothermal and photoelectricity device (CTPV) equipped in the system was designed to address this problem. In accordance with the structure of the device, LightTools optical software was selected to analyze the variation trend of the light escape rate of the device with the different incident angles. On the basis of the calculation results, an experimental test system was used to investigate the relationship of the air temperature of the inlet and the outlet, total output power of the solar cells, and photothermal and photoelectricity efficiency of the device with the operation time during a sunny day. Research results reveal that the light escape rate of the device is 5.36% at an incidence angle of 12°. At a velocity of 1.5 m/s, the maximum air temperature of the outlet can reach 55.6 °C, and the total output power of the solar cells is 474.4 W. The variation of the total power of the solar cells is consistent with the simulation results. The maximum instantaneous heat collection and the maximum photothermal and photoelectricity efficiency of the device are 306 W and 60.4%, respectively, and the average efficiency is 44.9%. This study can serve as a reference for compound parabolic concentration technology applied for soil heating in facility agricultural soil heating systems.
      PubDate: 2022-03-04
       
  • Enhanced Electrochemical Performance of Poly(ethylene oxide) Composite
           Polymer Electrolyte via Incorporating Lithiated Covalent Organic Framework
           

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      Abstract: The lithiated covalent organic framework (named TpPa-SO3Li), which was prepared by a mild chemical lithiation strategy, was introduced in poly(ethylene oxide) (PEO) to produce the composite polymer electrolytes (CPEs). Li-ion can transfer along the PEO chain or across the layer of TpPa-SO3Li within the nanochannels, resulting in a high Li-ion conductivity of 3.01 × 10−4 S/cm at 60 °C. When the CPE with 0.75 wt.% TpPa-SO3Li was used in the LiFePO4 Li solid-state battery, the cell delivered a stable capacity of 125 mA·h/g after 250 cycles at 0.5 C, 60 °C. In comparison, the cell using the CPE without TpPa-SO3Li exhibited a capacity of only 118 mA·h/g.
      PubDate: 2022-02-01
       
  • Visible Light-Responsive N-Doped TiO2 Photocatalysis: Synthesis,
           Characterizations, and Applications

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      Abstract: Photocatalysis based on semiconductors has recently been receiving considerable research interest because of its extensive applications in environmental remediation and renewable energy generation. Various semiconductor-based materials that are vital to solar energy utilization have been extensively investigated, among which titanium oxide (TiO2) has attracted considerable attention because of its exceptional physicochemical characteristics. However, the sluggish responsiveness to visible light in the solar spectrum and the inefficient separation of photoinduced electron–hole pairs hamper the practical application of TiO2 materials. To overcome the aforementioned serious drawbacks of TiO2, numerous strategies, such as doping with foreign atoms, particularly nitrogen (N), have been improved in the past few decades. This review aims to provide a comprehensive update and description of the recent developments of N-doped TiO2 materials for visible light-responsive photocatalysis, such as (1) the preparation of N-doped/co-doped TiO2 photocatalysts and (2) mechanistic studies on the reasons for visible light response. Furthermore, the most recent and significant advances in the field of solar energy applications of modified N-doped TiO2 are summarized. The analysis indicated the critical need for further development of these types of materials for the solar-to-energy conversion, particularly for water splitting purposes.
      PubDate: 2022-02-01
       
  • Recent Developments of Antimony-Based Anodes for Sodium- and Potassium-Ion
           Batteries

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      Abstract: The development of sodium-ion (SIBs) and potassium-ion batteries (PIBs) has increased rapidly because of the abundant resources and cost-effectiveness of Na and K. Antimony (Sb) plays an important role in SIBs and PIBs because of its high theoretical capacity, proper working voltage, and low cost. However, Sb-based anodes have the drawbacks of large volume changes and weak charge transfer during the charge and discharge processes, thus leading to poor cycling and rapid capacity decay. To address such drawbacks, many strategies and a variety of Sb-based materials have been developed in recent years. This review systematically introduces the recent research progress of a variety of Sb-based anodes for SIBs and PIBs from the perspective of composition selection, preparation technologies, structural characteristics, and energy storage behaviors. Moreover, corresponding examples are presented to illustrate the advantages or disadvantages of these anodes. Finally, we summarize the challenges of the development of Sb-based materials for Na/K-ion batteries and propose potential research directions for their further development.
      PubDate: 2022-02-01
       
  • Development of High-Energy-Density Liquid Aerospace Fuel: A Perspective

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      Abstract: Aerospace aircraft has significantly improved the life quality of human beings and extended the capability of space explosion since its appearance in 1903, in which liquid propellants or fuels provide the key power source. For jet fuels, its property of energy density plays an important role in determining the flight range, load, and performance of the aircraft. Therefore, the design and fabrication of high-energy-density (HED) fuels attract more and more attention from researchers all over the world. Herein, we briefly introduce the development of liquid jet fuels and HED fuels and demonstrate the future development of HED fuels. To further improve the energy density of fuel, the approaches of design and construction of multi-cyclic and stained molecule structures are proposed. To break through the density limit of hydrocarbon fuels, the addition of energetic nanoparticles in HED fuels to produce nanofluid or gelled fuels may provide a facile and effective method to significantly increase the energy density. This work provides the perspective for the development of HED fuels for advanced aircrafts.
      PubDate: 2022-02-01
       
  • Fluorine-Doped Hard Carbon as the Advanced Performance Anode Material of
           Sodium-Ion Batteries

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      Abstract: F-doping hard carbon (F–HC) was synthesized through a mild fluorination at temperature at relative low temperature as the potential anode for sodium-ion batteries (SIBs). The F-doping treatment to HC expands interlayer distance and creates some defects in the graphitic framework, which has the ability to improve Na+ storage capability through the intercalation and pore-filling process a simultaneously. In addition, the electrically conductive semi-ionic C–F bond in F–HC that can be adjusted by the fluorination temperature facilitates electron transport throughout the electrode. Therefore, F–HC exhibits higher specific capability and better cycling stability than pristine HC. Particularly, F–HC fluorinated at 100 °C (F–HC100) delivers the reversible capability of 343 mAh/g at 50 mAh/g, with the Coulombic efficiency of 78.13%, and the capacity retention remains as 95.81% after 100 cycles. Moreover, the specific capacity of F–HC100 returns to 340 mAh/g after the rate capability test demonstrates its stability even at high current density. The enhanced specific capacity of F–HC, especially at low-voltage region, has the great potential as the anode of SIBs with high energy density.
      PubDate: 2022-01-29
       
  • Recent Advances in the Catalytic Upgrading of Biomass Platform Chemicals
           Via Hydrotalcite-Derived Metal Catalysts

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      Abstract: With the world’s fossil fuels being finite in nature, an increasing interest focuses on the application of alternative renewable resources such as biomass. Biomass-derived platform chemicals with abundant functional groups have the potential to replace bulk chemicals for the production of value-added chemicals, fuels, and materials. The upgrading of these platform chemicals relies on the development of efficient catalytic systems. Hydrotalcite, with its wide compositional variety, tuneable anion-exchange capacity, and controlled acidity/basicity sites demonstrates great potential in the catalytic upgrading of biomass and the derived platform chemicals. The past decade has witnessed the emergence of research achievements on the development of efficient and robust hydrotalcite-derived metal catalysts and their applications in the upgrading of biomass or the derived platform chemicals. In this review, we aim to summarize the recent advances on the catalytic upgrading of biomass-derived platform chemicals (e.g., furfural, 5-hydroxymethylfurfural, levulinic acid, and glycerol) via hydrotalcite-derived metal catalysts. We also observed that the crucial role of using hydrotalcite-derived catalysts relies on their strong metal–support interactions. As a result, a section focusing on the discussion of the metal–support interactions of hydrotalcite-derived catalysts was provided.
      PubDate: 2022-01-24
       
  • Construction of Desirable NiCoTe2 Nanosheet Arrays on a Carbon Cloth
           Substrate as a Positive Electrode Material for a High-Performance
           Asymmetric Supercapacitor

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      Abstract: Nickel–cobalt tellurides are deemed as promising electrode materials for energy storage devices due to their superior conductivity and theoretical specific capacitance. Here, NiCoTe2 was successfully fabricated on carbon cloth by facile electrodeposition and hydrothermal synthesis, which can directly serve as a binderless electrode. The NiCoTe2 with interconnected nanosheet arrays on a conductive carbon substrate showed a high specific capacitance (924 F/g at 1 A/g) and robust long-term cycling stability (89.6% retention after 5000 cycles). In addition, the assembled NiCoTe2//activiated carbon hybrid supercapacitor achieved a high energy and power density with a short charging time (42.26 Wh/kg at a power density of 760.96 W/kg). This work provides a novel idea to produce bimetallic nickel–cobalt telluride nanosheet array electrodes for high-performance hybrid supercapacitors.
      PubDate: 2022-01-21
       
  • Pore-Scale Investigation of Coupled Two-Phase and Reactive Transport in
           the Cathode Electrode of Proton Exchange Membrane Fuel Cells

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      Abstract: A three-dimensional multicomponent multiphase lattice Boltzmann model (LBM) is established to model the coupled two-phase and reactive transport phenomena in the cathode electrode of proton exchange membrane fuel cells. The gas diffusion layer (GDL) and microporous layer (MPL) are stochastically reconstructed with the inside dynamic distribution of oxygen and liquid water resolved, and the catalyst layer is simplified as a superthin layer to address the electrochemical reaction, which provides a clear description of the flooding effect on mass transport and performance. Different kinds of electrodes are reconstructed to determine the optimum porosity and structure design of the GDL and MPL by comparing the transport resistance and performance under the flooding condition. The simulation results show that gradient porosity GDL helps to increase the reactive area and average concentration under flooding. The presence of the MPL ensures the oxygen transport space and reaction area because liquid water cannot transport through micropores. Moreover, the MPL helps in the uniform distribution of oxygen for an efficient in-plane transport capacity. Crack and perforation structures can accelerate the water transport in the assembly. The systematic perforation design yields the best performance under flooding by separating the transport of liquid water and oxygen.
      PubDate: 2022-01-03
       
  • Manganese-Based Catalysts for Indoor Volatile Organic Compounds
           Degradation with Low Energy Consumption and High Efficiency

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      Abstract: With the development of industrialization, the emission of volatile organic compounds (VOCs) to atmosphere causes serious environmental problems and the treatment of VOCs needs to consume a lot of energy. Moreover, indoor VOCs are seriously harmful to human health. Thus, there is an urgent requirement for the development of indoor VOCs treatment technologies. Catalytic degradation of VOCs, as a low energy consumption, high efficiency, and easy to achieve manner, has been widely studied in related fields. As a kind of transition metal catalyst, manganese-based catalysts have attracted a lot of attention in the catalytic degradation of VOCs because of their unique advantages including high efficiency, low cost, and excellent stability. This paper reviews the state-of-the-art progress of manganese-based catalysts for VOCs catalytic degradation. We introduce the thermocatalytic, photocatalytic and photo-thermocatalytic degradation of VOCs on manganese-based catalysts in this paper. The optimization of manganese-based catalysts by means of structural design, decorating modification and defect engineering is discussed. Graphical
      PubDate: 2021-12-13
       
  • Comparative Electrocatalytic Oxygen Evolution Reaction Studies of Spinel
           NiFe2O4 and Its Nanocarbon Hybrids

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      Abstract: Electrocatalytic oxygen evolution reaction (OER) is one of the crucial reactions for converting renewable electricity into chemical fuel in the form of hydrogen. To date, there is still a challenge in designing ideal cost-effective OER catalysts with excellent activity and robust durability. The hybridization of transition metal oxides and carbonaceous materials is one of the most effective and promising strategies to develop high-performance electrocatalysts. Herein, this work synthesized hybrids of NiFe2O4 spinel materials with two-dimensional (2D) graphene oxide and one-dimensional (1D) carbon nanotubes using a facile solvothermal approach. Electrocatalytic activities of NiFe2O4 with 2D graphene oxide toward OER were realized to be superior even to the 1D carbon nanotube-based electrocatalyst in terms of overpotential to reach a current density of 10 mA/cm2 as well as Tafel slopes. The NiFe2O4 with 2D graphene oxide hybrid exhibits good stability with an overpotential of 327 mV at a current density of 10 mA/cm2 and a Tafel slope of 103 mV/dec. The high performance of NiFe2O4 with 2D graphene oxide is mainly attributed to its unique morphology, more exposed active sites, and a porous structure with a high surface area. Thus, an approach of hybridizing a metal oxide with a carbonaceous material offers an attractive platform for developing an efficient electrocatalyst for water electrochemistry applications.
      PubDate: 2021-12-10
       
  • Correction to: Influence of Orifice Position Deviations on Distribution
           Performance of Gravity-Type Liquid Distributor Analyzed Through
           Mathematical Pathway

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      Abstract: A correction to this paper has been published: https://doi.org/10.1007/s12209-021-00297-5
      PubDate: 2021-12-01
       
  • Solubility and Thermodynamic Properties of Sulfamethazine–Saccharin
           Cocrystal in Pure and Binary (Acetonitrile + 2-Propanol) Solvents

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      Abstract: In this work, a new crystallization method was used to prepare two polymorphs of sulfamethazine–saccharin (SMT–SAC) cocrystal in bulk. The purity and crystal form of both polymorphs were confirmed by optical microscopy, scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. Moreover, the solubility of the stable form (form II) was determined by gravimetric analysis in nine pure solvents and one binary (acetonitrile + 2-propanol) solvent at temperatures ranging from 278.15 to 348.15 K at atmospheric pressure. Experimental data were correlated using the modified Apelblat model, the λh equation, the nonrandom two-liquid (NRTL) model, the Jouyban–Acree model, and the CNIBS/Redlich–Kister model. Finally, the apparent thermodynamic properties, such as \(\Delta_{\text{dis}} G\) , ΔdisH, and ΔdisS, were calculated on the basis of the activity coefficient obtained by the NRTL model. All the models correlate well, and all the experimental and calculated results indicate that the dissolution behavior of SMT–SAC cocrystal form II is a spontaneous, endothermic, and entropy-driven process.
      PubDate: 2021-12-01
       
  • Electroreduction of Carbon Dioxide by Heterogenized Cofacial Porphyrins

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      Abstract: Great attention has been paid to cofacial porphyrins due to their many unique advantages over their monomeric analogs. However, their synthesis is usually complicated. In this work, a facile impregnation method for preparing heterogenized, cofacially stacked porphyrins is proposed. An anionic porphyrin is introduced as an underlayer for immobilization of cationic cobalt porphyrin via electrostatic force. The metal center of the underlying molecule contributes to the electronic structure of the upper cationic cobalt porphyrin. Screening reveals the anionic iron porphyrin to be the most efficient underlayer molecule, lowering the activation energy barrier of CO2 electroreduction, with an improved turnover frequency by 74% to 8.0 s−1 at − 0.6 V versus RHE.
      PubDate: 2021-08-03
       
 
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