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Open Access journal
ISSN (Online) 2198-3844
Published by John Wiley and Sons [1616 journals]
- An Alternative Host Material for Long-Lifespan Blue Organic Light-Emitting
Diodes Using Thermally Activated Delayed Fluorescence
Authors: Soo-Ghang Ihn; Namheon Lee, Soon Ok Jeon, Myungsun Sim, Hosuk Kang, Yongsik Jung, Dal Ho Huh, Young Mok Son, Sae Youn Lee, Masaki Numata, Hiroshi Miyazaki, Rafael Gómez-Bombarelli, Jorge Aguilera-Iparraguirre, Timothy Hirzel, Alán Aspuru-Guzik, Sunghan Kim, Sangyoon Lee
Abstract: It has been challenging to find stable blue organic light emitting diodes (OLEDs) that rely on thermally activated delayed fluorescence (TADF). Lack of stable host materials well-fitted to the TADF emitters is one of the critical reasons. The most popular host for blue TADF, bis[2-(diphenylphosphino)phenyl] ether oxide (DPEPO), leads to unrealistically high maximum external quantum efficiency. DPEPO is however an unstable material and has a poor charge transporting ability, which in turn induces an intrinsic short OLED operating lifespan. Here, an alternative host material is introduced which educes the potential efficiency and device lifespan of given TADF emitters with the appropriateness of replacing the most popular host material, DPEPO, in developing blue TADF emitters. It simultaneously provides much longer device lifespan and higher external quantum efficiency at a practical brightness due to its high material stability and electron-transport-type character well-fitted for hole-transport-type TADF emitters.An alternative host material is introduced with the appropriateness of replacing the most popular host material, DPEPO, in developing blue thermally activated delayed fluorescent (TADF) emitters. It simultaneously provides much longer device lifespan and higher external quantum efficiency at a practical brightness due to its high material stability and electron-transport-type character well-fitted for hole-transport-type TADF emitters.
- Smart Windows: Ultrathin Fluidic Laminates for Large-Area Façade
Integration and Smart Windows (Adv. Sci. 3/2017)
Authors: Benjamin P. V. Heiz; Zhiwen Pan, Gerhard Lautenschläger, Christin Sirtl, Matthias Kraus, Lothar Wondraczek
Abstract: In article number 1600362, Lothar Wondraczek and co-workers present glass–glass fluidic devices for large-area integration with adaptive façades and smart windows, enabling harnessing and dedicated control of liquids for added functionality in the building envelope by wrapping buildings into a fluidic layer.
- Contents: (Adv. Sci. 3/2017)
- Masthead: (Adv. Sci. 3/2017)
- Energy Storage: Advanced Micro/Nanostructures for Lithium Metal Anodes
(Adv. Sci. 3/2017)
Authors: Rui Zhang; Nian-Wu Li, Xin-Bing Cheng, Ya-Xia Yin, Qiang Zhang, Yu-Guo Guo
Abstract: Yu-Guo Guo, Qiang Zhang, and co-workers review the use of micro/nanostructured lithium metal anodes to retard the formation of lithium dendrites in lithium metal batteries in article 1600445. With the unique surface, pore, and connecting structures of different nanomaterials, the lithium plating/stripping processes are significantly regulated.
- Energy Storage: Polyanion-Type Electrode Materials for Sodium-Ion
Batteries (Adv. Sci. 3/2017)
Authors: Qiao Ni; Ying Bai, Feng Wu, Chuan Wu
Abstract: Na-ion batteries, promising large-scale energy storage and conversion devices, can store wind and solar energy through smart grids efficiently, that provides power supply to thousands of households. In article number 1600275, Chuan Wu and co-workers systematically summarize the characteristics of different kinds of polyanion-type compounds for Na-ion batteries. In addition, constructive strategies to enhance the electrochemical performances of such materials are also proposed.
- Black Phosphorus Quantum Dots with Tunable Memory Properties and
Multilevel Resistive Switching Characteristics
Authors: Su-Ting Han; Liang Hu, Xiandi Wang, Ye Zhou, Yu-Jia Zeng, Shuangchen Ruan, Caofeng Pan, Zhengchun Peng
Abstract: Solution-processed black phosphorus quantum-dot-based resistive random access memory is demonstrated with tunable characteristics, multilevel data storage, and ultrahigh ON/OFF ratio. Effects of the black phosphorous quantum dots layer thickness and the compliance current setting on resistive switching behavior are systematically studied. Our devices can yield a series of SET voltages and current levels, hence having the potential for practical applications in the flexible electronics industry.
- Taking Electrons out of Bioelectronics: From Bioprotonic Transistors to
Authors: Xenofon Strakosas; John Selberg, Zahra Hemmatian, Marco Rolandi
Abstract: From cell-to-cell communication to metabolic reactions, ions and protons (H+) play a central role in many biological processes. Examples of H+ in action include oxidative phosphorylation, acid sensitive ion channels, and pH dependent enzymatic reactions. To monitor and control biological reactions in biology and medicine, it is desirable to have electronic devices with ionic and protonic currents. Here, we summarize our latest efforts on bioprotonic devices that monitor and control a current of H+ in physiological conditions, and discuss future potential applications. Specifically, we describe the integration of these devices with enzymatic logic gates, bioluminescent reactions, and ion channels.Bioprotonic devices can monitor, and control H+ currents for biological applications. Pd/PdHx couple is used as a transducer of H+ currents into electronic currents and vice versa. The use of Pd/PdHx in bioelectronics has opened the doors to new type of applications and devices including enzyme logic, control of bioluminescence, and platforms for integration of ion channels toward intracellular communication.
- Brown Adipose Tissue Bioenergetics: A New Methodological Approach
Authors: María Calderon-Dominguez; Martín Alcalá, David Sebastián, Antonio Zorzano, Marta Viana, Dolors Serra, Laura Herrero
Abstract: The rediscovery of brown adipose tissue (BAT) in humans and its capacity to oxidize fat and dissipate energy as heat has put the spotlight on its potential as a therapeutic target in the treatment of several metabolic conditions including obesity and diabetes. To date the measurement of bioenergetics parameters has required the use of cultured cells or extracted mitochondria with the corresponding loss of information in the tissue context. Herein, we present a method to quantify mitochondrial bioenergetics directly in BAT. Based on XF Seahorse Technology, we assessed the appropriate weight of the explants, the exact concentration of each inhibitor in the reaction, and the specific incubation time to optimize bioenergetics measurements. Our results show that BAT basal oxygen consumption is mostly due to proton leak. In addition, BAT presents higher basal oxygen consumption than white adipose tissue and a positive response to b-adrenergic stimulation. Considering the whole tissue and not just subcellular populations is a direct approach that provides a realistic view of physiological respiration. In addition, it can be adapted to analyze the effect of potential activators of thermogenesis, or to assess the use of fatty acids or glucose as a source of energy.The study of bioenergetics in brown adipose tissue explants is described in this novel methodological approach that utilizes Seahorse technology. This method does not require mitochondrial isolation and detects oxygen consumption in real time. The addition of respiratory inhibitors or thermogenic inducers proves its application to study brown adipose tissue functionality and for antiobesity drug testing.
- Label-Free and Regenerative Electrochemical Microfluidic Biosensors for
Continual Monitoring of Cell Secretomes
Authors: Su Ryon Shin; Tugba Kilic, Yu Shrike Zhang, Huseyin Avci, Ning Hu, Duckjin Kim, Cristina Branco, Julio Aleman, Solange Massa, Antonia Silvestri, Jian Kang, Anna Desalvo, Mohammed Abdullah Hussaini, Su-Kyoung Chae, Alessandro Polini, Nupura Bhise, Mohammad Asif Hussain, HeaYeon Lee, Mehmet R. Dokmeci, Ali Khademhosseini
Abstract: Development of an efficient sensing platform capable of continual monitoring of biomarkers is needed to assess the functionality of the in vitro organoids and to evaluate their biological responses toward pharmaceutical compounds or chemical species over extended periods of time. Here, a novel label-free microfluidic electrochemical (EC) biosensor with a unique built-in on-chip regeneration capability for continual measurement of cell-secreted soluble biomarkers from an organoid culture in a fully automated manner without attenuating the sensor sensitivity is reported. The microfluidic EC biosensors are integrated with a human liver-on-a-chip platform for continual monitoring of the metabolic activity of the organoids by measuring the levels of secreted biomarkers for up to 7 d, where the metabolic activity of the organoids is altered by a systemically applied drug. The variations in the biomarker levels are successfully measured by the microfluidic regenerative EC biosensors and agree well with cellular viability and enzyme-linked immunosorbent assay analyses, validating the accuracy of the unique sensing platform. It is believed that this versatile and robust microfluidic EC biosensor that is capable of automated and continual detection of soluble biomarkers will find widespread use for long-term monitoring of human organoids during drug toxicity studies or efficacy assessments of in vitro platforms.A reusable label-free microfluidics electrochemical biosensor is developed and integrated with a human organoids system. This biosensor with an on-chip built-in regeneration capability is successfully controlled in a fully automated manner. The samples from a human liver-on-a-chip are measured using this platform, which show similar results with those obtained from enzyme-linked immunosorbent assay tests before and after drug treatment.
- A General Electrode Design Strategy for Flexible Fiber
Micro-Pseudocapacitors Combining Ultrahigh Energy and Power Delivery
Authors: Ping Li; Jing Li, Zhe Zhao, Zhengsong Fang, Meijia Yang, Zhongke Yuan, You Zhang, Qiang Zhang, Wei Hong, Xudong Chen, Dingshan Yu
Abstract: Herein, a general strategy is proposed to boost the energy storage capability of pseudocapacitive materials (i.e., MnO2) to their theoretical limits in unconventional 1D fiber configuration by rationally designing bicontinuous porous Ni skeleton@metal wire “sheath–core” metallic scaffold as a versatile host. As a proof of concept, the 1D metallic scaffold supported-MnO2 fiber electrode is demonstrated. The proposed “sheath” design not only affords large electrode surface area with ordered macropores for large electrolyte-ion accessibility and high electroactive material loading, but also renders interconnected porous metallic skeleton for efficient electronic and ionic transport, while the metallic “core” functions as an extra current collector to promote long-distance electron transport and electron collection. Benefiting from all these merits, the optimized fiber electrode yields unprecedented specific areal capacitance of 1303.6 mF cm−2 (1278 F g−1 based on MnO2, approaching the theoretical value of 1370 F g−1) in liquid KOH and 847.22 mF cm−2 in polyvinyl alcohol (PVA)/KOH gel electrolyte, 2–350 times of previously reported fiber electrodes. The solid-state fiber micro-pseudocapacitors simultaneously achieve remarkable areal energy and power densities of 18.83 µWh cm−2 and 16.33 mW cm−2, greatly exceeding the existing symmetric fiber supercapacitors, together with long cycle life and high rate capability.A general strategy to boost the energy storage capability of pseudocapacitive materials (i.e., MnO2) to their theoretical limits in one-dimensional (1D) fiber format by constructing bicontinuous porous framework sheathed 1D metallic scaffold as a versatile host is proposed. As a proof of concept, the optimized fiber micro-pseudocapacitors using MnO2 concurrently achieve remarkable areal capacitance, ultrahigh areal power and energy densities.
- Strategies Based on Nitride Materials Chemistry to Stabilize Li Metal
Authors: Yizhou Zhu; Xingfeng He, Yifei Mo
Abstract: Lithium metal battery is a promising candidate for high-energy-density energy storage. Unfortunately, the strongly reducing nature of lithium metal has been an outstanding challenge causing poor stability and low coulombic efficiency in lithium batteries. For decades, there are significant research efforts to stabilize lithium metal anode. However, such efforts are greatly impeded by the lack of knowledge about lithium-stable materials chemistry. So far, only a few materials are known to be stable against Li metal. To resolve this outstanding challenge, lithium-stable materials have been uncovered out of chemistry across the periodic table using first-principles calculations based on large materials database. It is found that most oxides, sulfides, and halides, commonly studied as protection materials, are reduced by lithium metal due to the reduction of metal cations. It is discovered that nitride anion chemistry exhibits unique stability against Li metal, which is either thermodynamically intrinsic or a result of stable passivation. The results here establish essential guidelines for selecting, designing, and discovering materials for lithium metal protection, and propose multiple novel strategies of using nitride materials and high nitrogen doping to form stable solid-electrolyte-interphase for lithium metal anode, paving the way for high-energy rechargeable lithium batteries.Novel stabilization strategies for Li metal anode are proposed by uncovering lithium-stable materials chemistry across the periodic table using first-principles calculations. Nitride anion chemistry exhibits unique lithium stability, which is thermodynamically intrinsic or a result of stable passivation. Applying nitride interphase and nitrogen doping provides ultimate stability to protect lithium metal anode.
- Coordination of Surface-Induced Reaction and Intercalation: Toward a
High-Performance Carbon Anode for Sodium-Ion Batteries
Authors: Weimin Chen; Chaoji Chen, Xiaoqin Xiong, Pei Hu, Zhangxiang Hao, Yunhui Huang
Abstract: Oxygen-rich carbon material is successfully fabricated from a porous carbon and evaluated as anode for sodium-ion battery. With the strategy of optimal combination of fast surface redox reaction and reversible intercalation, the oxygen-rich carbon anode exhibits a large reversible capacity (447 mAh g−1 at 0.2 A g−1), high rate capability (172 mAh g−1 at 20 A g−1), and excellent cycling stability.
- Furan Is Superior to Thiophene: A Furan-Cored AIEgen with Remarkable
Chromism and OLED Performance
Authors: Zheng Zhao; Han Nie, Congwu Ge, Yuanjing Cai, Yu Xiong, Ji Qi, Wenting Wu, Ryan T. K. Kwok, Xike Gao, Anjun Qin, Jacky W. Y. Lam, Ben Zhong Tang
Abstract: Furan-cored AIEgen namely tetraphenylethylene-furan (TPE-F) is developed by diyne cyclization and its fluorescent and chemical properties are investigated and compared with its thiophene analogue. Results show that furan is superior to thiophene in terms of fluorescence, chromism, and charge transport. The mechanism of chromism of TPE-F is investigated and its efficient solid-state photoluminescence and good charge-transporting property enable it to serve as light-emitting material for the construction of electroluminescence devices with excellent performance. This work not only demonstrates an efficient strategy for constructing furan-cored AIEgens but also indicates that they are promising as advanced optoelectronic materials.Furan-cored AIEgen by diyne cyclization is demonstrated for the first time and its fluorescent and chemical properties are investigated and compared with its thiophene analog. Results show that furan is superior to thiophene in terms of fluorescence, chromism, and charge transport. This study affords an efficient strategy for constructing furan-cored AIEgens and demonstrates their potential as advanced optoelectronic materials.
- Plants and Light Manipulation: The Integrated Mineral System in Okra
Authors: Maria Pierantoni; Ron Tenne, Vlad Brumfeld, Vladimir Kiss, Dan Oron, Lia Addadi, Steve Weiner
Abstract: Calcium oxalate and silica minerals are common components of a variety of plant leaves. These minerals are found at different locations within the leaf, and there is little conclusive evidence about the functions they perform. Here tools are used from the fields of biology, optics, and imaging to investigate the distributions of calcium oxalate, silica minerals, and chloroplasts in okra leaves, in relation to their functions. A correlative approach is developed to simultaneously visualize calcium oxalates, silica minerals, chloroplasts, and leaf soft tissue in 3D without affecting the minerals or the organic components. This method shows that in okra leaves silica and calcium oxalates, together with chloroplasts, form a complex system with a highly regulated relative distribution. This distribution points to a significant role of oxalate and silica minerals to synergistically optimize the light regime in the leaf. The authors also show directly that the light scattered by the calcium oxalate crystals is utilized for photosynthesis, and that the ultraviolet component of light passing through silica bodies, is absorbed. This study thus demonstrates that calcium oxalates increase the illumination level into the underlying tissue by scattering the incoming light, and silica reduces the amount of UV radiation entering the tissue.Calcium oxalate and silica minerals are common components of plant leaves. Little is known about their functions. A correlative approach to visualize calcium oxalates, silica, chloroplasts, and soft tissue in 3D was developed. The authors show how calcium oxalates increase the illumination into the underlying tissue by scattering light, and silica reduces the amount of UV radiation entering the tissue.
- “Self-Peel-Off” Transfer Produces Ultrathin
Polyvinylidene-Fluoride-Based Flexible Nanodevices
Authors: Yanlong Tai; Gilles Lubineau
Abstract: Here, a new strategy, self-peel-off transfer, for the preparation of ultrathin flexible nanodevices made from polyvinylidene-fluoride (PVDF) is reported. In this process, a functional pattern of nanoparticles is transferred via peeling from a temporary substrate to the final PVDF film. This peeling process takes advantage of the differences in the work of adhesion between the various layers (the PVDF layer, the nanoparticle-pattern layer and the substrate layer) and of the high stresses generated by the differential thermal expansion of the layers. The work of adhesion is mainly guided by the basic physical/chemical properties of these layers and is highly sensitive to variations in temperature and moisture in the environment. The peeling technique is tested on a variety of PVDF-based functional films using gold/palladium nanoparticles, carbon nanotubes, graphene oxide, and lithium iron phosphate. Several PVDF-based flexible nanodevices are prepared, including a single-sided wireless flexible humidity sensor in which PVDF is used as the substrate and a double-sided flexible capacitor in which PVDF is used as the ferroelectric layer and the carrier layer. Results show that the nanodevices perform with high repeatability and stability. Self-peel-off transfer is a viable preparation strategy for the design and fabrication of flexible, ultrathin, and light-weight nanodevices.Mechanism of the “self-peel-off” transfer (SPOT) technique via the temperature- and humidity-sensitive properties of both polyvinylidene-fluoride (PVDF) and nanomaterials. SPOT is a promising strategy to fabricate flexible, ultrathin, and light-weighted PVDF-based nanodevices.
- Hot Hole Enhanced Synergistic Catalytic Oxidation on Pt-Cu Alloy Clusters
Authors: Lanchun Zhang; Chuancheng Jia, Shuren He, Youtao Zhu, Yana Wang, Zhenhuan Zhao, Xiaochun Gao, Xiaomei Zhang, Yuanhua Sang, Dongju Zhang, Xiaohong Xu, Hong Liu
Abstract: Hot holes in Pt-Cu alloy clusters can act as catalyst to accelerate the intrinsic aerobic oxidation reactions. It is described that under visible light irradiation the synergistic alcohol catalytic oxidation on Pt-Cu alloy clusters (≈1.1 nm)/TiO2 nanobelts could be significant promoted by interband-excitation-generated long-lifetime hot holes in the clusters.
- Battery-Supercapacitor Hybrid Devices: Recent Progress and Future
Authors: Wenhua Zuo; Ruizhi Li, Cheng Zhou, Yuanyuan Li, Jianlong Xia, Jinping Liu
Abstract: Design and fabrication of electrochemical energy storage systems with both high energy and power densities as well as long cycling life is of great importance. As one of these systems, Battery-supercapacitor hybrid device (BSH) is typically constructed with a high-capacity battery-type electrode and a high-rate capacitive electrode, which has attracted enormous attention due to its potential applications in future electric vehicles, smart electric grids, and even miniaturized electronic/optoelectronic devices, etc. With proper design, BSH will provide unique advantages such as high performance, cheapness, safety, and environmental friendliness. This review first addresses the fundamental scientific principle, structure, and possible classification of BSHs, and then reviews the recent advances on various existing and emerging BSHs such as Li-/Na-ion BSHs, acidic/alkaline BSHs, BSH with redox electrolytes, and BSH with pseudocapacitive electrode, with the focus on materials and electrochemical performances. Furthermore, recent progresses in BSH devices with specific functionalities of flexibility and transparency, etc. will be highlighted. Finally, the future developing trends and directions as well as the challenges will also be discussed; especially, two conceptual BSHs with aqueous high voltage window and integrated 3D electrode/electrolyte architecture will be proposed.The fundamental scientific principle, structure, and possible classification of battery-supercapacitor hybrid devices (BSHs), outlining the recent advances on various existing and emerging BSHs, with the focus on materials and electrochemical performances, and finally providing the future developing trends and directions as well as the challenges are addressed in this review.
- The Strong Light-Emission Materials in the Aggregated State: What Happens
from a Single Molecule to the Collective Group
Authors: Qianqian Li; Zhen Li
Abstract: The strong light emission of organic luminogens in the aggregated state is essential to their applications as optoelectronic materials with good performance. In this review, with respect to the aggregation-induced emission and room-temperature phosphorescence luminogens, the important role of molecular packing modes is highlighted. As demonstrated in the selected examples, the molecular packing status in the aggregate state is affected by many factors, including the molecular configurations, the inherent electronic properties, the special functional groups, and so on. With the consideration of all these parameters, the strong fluorescence and phosphorescence in the aggregated state could be achieved in the rationally designed organic luminogens, providing some guidance for the further development.The packing modes in aggregated state play an crucial role in the light-emission behaviors, especially for aggregation-induced emission and room-temperature phosphorescence luminogens. In this review, the possible correlation of molecular structures, packing modes, and the fluorescence and phosphorescence in solid state, has been summarized by the investigation of corresponding crystal structures in typical examples.
- Genetic Assembly of Double-Layered Fluorescent Protein Nanoparticles for
Cancer Targeting and Imaging
Authors: Seong-Eun Kim; Sung Duk Jo, Koo Chul Kwon, You-Yeon Won, Jeewon Lee
Abstract: Hepatitis B virus capsid (HBVC), a self-assembled protein nanoparticle comprised of 180 or 240 subunit proteins, is used as a cage for genetic encapsulation of fluorescent proteins (FPs). The self-quenching of FPs is controlled by varying the spacing between FPs within the capsid structure. Double-layered FP nanoparticle possessing cancer cell-targeting capabilities is also produced by additionally attaching FPs and cancer cell receptor-binding peptides (affibodies) to the outer surface of the capsid. The generically modified HBVC with double layers of mCardinal FPs and affibodies (mC-DL-HBVC) exhibit a high fluorescence intensity and a strong photostability, and is efficiently internalized by cancer cells and significantly stable against intracellular degradation. The mC-DL-HBVC effectively detects tumor in live mice with enhanced tumor targeting and imaging efficiency with far less accumulation in the liver, compared to a conventional fluorescent dye, Cy5.5. This suggests the great potential of mC-DL-HBVC as a promising contrast agent for in vivo tumor fluorescence imaging.Double-Layered Fluorescent Protein Nanoparticle (DL-FPNP) showed excellent performance in in vivo cancer targeting and imaging. Hepatitis B virus capsid was genetically engineered to synthesize DL-FPNP that also presents the multi-copies of a cancer cell receptor-binding peptide on its outer surface. NIR irradiation to DL-FPNP showed far higher fluorescence emission and photostability than a conventional fluorescent dye (Cy5.5).
- Plasmonics of 2D Nanomaterials: Properties and Applications
Authors: Yu Li; Ziwei Li, Cheng Chi, Hangyong Shan, Liheng Zheng, Zheyu Fang
Abstract: Plasmonics has developed for decades in the field of condensed matter physics and optics. Based on the classical Maxwell theory, collective excitations exhibit profound light-matter interaction properties beyond classical physics in lots of material systems. With the development of nanofabrication and characterization technology, ultra-thin two-dimensional (2D) nanomaterials attract tremendous interest and show exceptional plasmonic properties. Here, we elaborate the advanced optical properties of 2D materials especially graphene and monolayer molybdenum disulfide (MoS2), review the plasmonic properties of graphene, and discuss the coupling effect in hybrid 2D nanomaterials. Then, the plasmonic tuning methods of 2D nanomaterials are presented from theoretical models to experimental investigations. Furthermore, we reveal the potential applications in photocatalysis, photovoltaics and photodetections, based on the development of 2D nanomaterials, we make a prospect for the future theoretical physics and practical applications.Optical properties of 2D nanomaterials especially the plasmonics of hybrid 2D nanomaterials with the plasmonic integration are focused in this Review. By summarizing latest progress of 2D nanomaterials, plasmonic mechanisms, exciton/plasmon coupling effects, and tuning methods are introduced. Strategies of making use of plasmonic properties and excitonic irradiations for photoelectric reactions and applications are discussed.
- Advanced Micro/Nanostructures for Lithium Metal Anodes
Authors: Rui Zhang; Nian-Wu Li, Xin-Bing Cheng, Ya-Xia Yin, Qiang Zhang, Yu-Guo Guo
Abstract: Owning to their very high theoretical capacity, lithium metal anodes are expected to fuel the extensive practical applications in portable electronics and electric vehicles. However, unstable solid electrolyte interphase and lithium dendrite growth during lithium plating/stripping induce poor safety, low Coulombic efficiency, and short span life of lithium metal batteries. Lately, varies of micro/nanostructured lithium metal anodes are proposed to address these issues in lithium metal batteries. With the unique surface, pore, and connecting structures of different nanomaterials, lithium plating/stripping processes have been regulated. Thus the electrochemical properties and lithium morphologies have been significantly improved. These micro/nanostructured lithium metal anodes shed new light on the future applications for lithium metal batteries.Micro/nanostructured lithium metal anodes are proposed to retard the formation of lithium dendrites in lithium metal batteries. With the unique surface, pore, and connecting structures of different nanomaterials, lithium plating/stripping processes have been modulated. The electrochemical properties and lithium morphologies have been significantly regulated.
- Recent Breakthroughs in Supercapacitors Boosted by Nitrogen-Rich Porous
Authors: Mei Yang; Zhen Zhou
Abstract: Featured with unique mechanical, electronic and chemical properties, nitrogen-doped carbon materials have become the research hotspot of energy storage. As electrode materials in supercapacitors (SCs), N-doped carbons have demonstrated intriguing flexibility and superb performances in a wide electrochemical window, equipped with versatile properties as both cathodes and anodes for constructing high voltage devices. Compared with limited doping level, N-rich and porous carbon materials (NPCs) are of great desire to release the restricted properties of N species and obtain high specific capacitances (>600 F g−1), pushing the energy density towards the battery level without scarifying the capacitor-level power ability. In this Research News we firstly discuss the key factors influencing the performance of NPC electrodes to disclose related charge storage mechanisms. In addition, the trade-off among N-content, porous structure and electrical conductivity is involved as well as electrochemical behaviors in different electrolytes. Also, various progressive developments are highlighted systematically ranging from asymmetric to symmetric and hybrid configurations, covering both aqueous and non-aqueous systems. Finally, some stubborn and unsolved problems are summarized, with prospective research guidelines on NPC-based SCs.Nitrogen-rich porous carbons (NPCs) have brought new breakthroughs to supercapacitors (SCs) due to their unique physic-chemical properties, and progressively pushed the energy density towards the battery level while keeping capacitor-level power output, realizing high energy-power integration to bridge the gap among current systems. Further, charge storage fundamentals in NPCs and progressive developments of NPC-based SC configurations are highlighted systematically.
- Observation of Metal Nanoparticles for Acoustic Manipulation
Authors: Mian Chen; Feiyan Cai, Chen Wang, Zhiyong Wang, Long Meng, Fei Li, Pengfei Zhang, Xin Liu, Hairong Zheng
Abstract: Use of acoustic trapping for the manipulation of objects is invaluable to many applications from cellular subdivision to biological assays. Despite remarkable progress in a wide size range, the precise acoustic manipulation of 0D nanoparticles where all the structural dimensions are much smaller than the acoustic wavelength is still present challenges. This study reports on the observation of metal nanoparticles with different nanostructures for acoustic manipulation. Results for the first time exhibit that the hollow nanostructures play more important factor than size in the nanoscale acoustic manipulation. The acoustic levitation and swarm aggregations of the metal nanoparticles can be easily realized at low energy and clinically acceptable acoustic frequency by hollowing their nanostructures. In addition, the behaviors of swarm aggregations can be flexibly regulated by the applied voltage and frequency. This study anticipates that the strategy based on the unique properties of the metal hollow nanostructures and the manipulation method will be highly desirable for many applications.The hollow metal nanoparticles are better able to be acoustically manipulated than particles with solid cores at low energy and clinically acceptable acoustic frequency. In addition, the behaviors of swarm aggregations can be flexibly regulated by the applied voltage and frequency. The study provides an insight into nanostructures' effect on acoustic manipulation and opens a new avenue to further applications.
- Recent Advances of Activatable Molecular Probes Based on Semiconducting
Polymer Nanoparticles in Sensing and Imaging
Authors: Yan Lyu; Kanyi Pu
Abstract: Molecular probes that change their signals in response to the target of interest have a critical role in fundamental biology and medicine. Semiconducting polymer nanoparticles (SPNs) have recently emerged as a new generation of purely organic photonic nanoagents with desirable properties for biological applications. In particular, tunable optical properties of SPNs allow them to be developed into photoluminescence, chemiluminescence, and photoacoustic probes, wherein SPNs usually serve as the energy donor and internal reference for luminescence and photoacoustic probes, respectively. Moreover, facile surface modification and intraparticle engineering provide the versatility to make them responsive to various biologically and pathologically important substances and indexes including small-molecule mediators, proteins, pH and temperature. This article focuses on recent advances in the development of SPN-based activatable molecular probes for sensing and imaging. The designs and applications of these probes are discussed in details, and the present challenges to further advance them into life science are also analyzed.Semiconducting polymer nanoparticles (SPNs) have shown great promise in life science. Recent advances of developing SPNs into smart activatable probes for biological sensing and molecular imaging are discussed.
- Transition Metal Carbides and Nitrides in Energy Storage and Conversion
Authors: Yu Zhong; Xinhui Xia, Fan Shi, Jiye Zhan, Jiangping Tu, Hong Jin Fan
- Emerging Trends in Phosphorene Fabrication towards Next Generation Devices
Authors: Sathish Chander Dhanabalan; Joice Sophia Ponraj, Zhinan Guo, Shaojuan Li, Qiaoliang Bao, Han Zhang
Abstract: The challenge of science and technology is to design and make materials that will dominate the future of our society. In this context, black phosphorus has emerged as a new, intriguing two-dimensional (2D) material, together with its monolayer, which is referred to as phosphorene. The exploration of this new 2D material demands various fabrication methods to achieve potential applications— this demand motivated this review. This article is aimed at supplementing the concrete understanding of existing phosphorene fabrication techniques, which forms the foundation for a variety of applications. Here, the major issue of the degradation encountered in realizing devices based on few-layered black phosphorus and phosphorene is reviewed. The prospects of phosphorene in future research are also described by discussing its significance and explaining ways to advance state-of-art of phosphorene-based devices. In addition, a detailed presentation on the demand for future studies to promote well-systemized fabrication methods towards large-area, high-yield and perfectly protected phosphorene for the development of reliable devices in optoelectronic applications and other areas is offered.The degradation encountered in realizing few-layered black phosphorus and phosphorene devices is reviewed. In particular, a detailed presentation of the demand for future studies to promote well-systemized fabrication methods towards large-area, high-yield and perfectly protected phosphorene for the development of reliable devices in optoelectronic applications and other areas is offered.
- Materials Design and System Construction for Conventional and New-Concept
Authors: Zhong Wu; Lin Li, Jun-min Yan, Xin-bo Zhang
Abstract: With the development of renewable energy and electrified transportation, electrochemical energy storage will be more urgent in the future. Supercapacitors have received extensive attention due to their high power density, fast charge and discharge rates, and long-term cycling stability. During past five years, supercapacitors have been boomed benefited from the development of nanostructured materials synthesis and the promoted innovation of devices construction. In this review, we have summarized the current state-of-the-art development on the fabrication of high-performance supercapacitors. From the electrode material perspective, a variety of materials have been explored for advanced electrode materials with smart material-design strategies such as carbonaceous materials, metal compounds and conducting polymers. Proper nanostructures are engineered to provide sufficient electroactive sites and enhance the kinetics of ion and electron transport. Besides, new-concept supercapacitors have been developed for practical application. Microsupercapacitors and fiber supercapacitors have been explored for portable and compact electronic devices. Subsequently, we have introduced Li-/Na-ion supercapacitors composed of battery-type electrodes and capacitor-type electrode. Integrated energy devices are also explored by incorporating supercapacitors with energy conversion systems for sustainable energy storage. In brief, this review provides a comprehensive summary of recent progress on electrode materials design and burgeoning devices constructions for high-performance supercapacitors.Supercapacitors have received extensive attention as one of effective energy storage devices for future development. In this review, the state-of-the-art advancement on aspects of supercapacitors such as electrode materials design, system construction and so on are comprehensively summarized. The smart material-design strategies and promoted innovation of devices construction have boosted their electrochemical performances and practical applications.
- Orientation and Incorporation of Photosystem I in Bioelectronics Devices
Enabled by Phage Display
Authors: Pavlo Gordiichuk; Diego Pesce, Olga E. Castañeda Ocampo, Alessio Marcozzi, Gert-Jan A. H. Wetzelaer, Avishek Paul, Mark Loznik, Ekaterina Gloukhikh, Shachar Richter, Ryan C. Chiechi, Andreas Herrmann
Abstract: Interfacing proteins with electrode surfaces is important for the field of bioelectronics. Here, a general concept based on phage display is presented to evolve small peptide binders for immobilizing and orienting large protein complexes on semiconducting substrates. Employing this method, photosystem I is incorporated into solid-state biophotovoltaic cells.
- Transmission Electron Microscopy as a Tool for the Characterization of
Soft Materials: Application and Interpretation
Authors: Linda E. Franken; Egbert J. Boekema, Marc C. A. Stuart
Abstract: Transmission electron microscopy (TEM) provides direct structural information on nano-structured materials and is popular as a characterization tool in soft matter and supramolecular chemistry. However, technical aspects of sample preparation are overlooked and erroneous image interpretations are regularly encountered in the literature. There are three most commonly used TEM methods as we derived from literature: drying, staining and cryo-TEM, which are explained here with respect to their application, limitations and interpretation. Since soft matter chemistry relies on a lot of indirect evidence, the role of TEM for the correct evaluation of the nature of an assembly is very large. Mistakes in application and interpretation can therefore have enormous impact on the quality of present and future studies. We provide helpful background information of these three techniques, the information that can and cannot be derived from them and provide assistance in selecting the right technique for soft matter imaging. This essay warns against the use of drying and explains why. In general cryo-TEM is by far the best suited method and many mistakes and over-interpretations can be avoided by the use of this technique.The most popular electron microscopy methods for soft and supramolecular systems are reviewed with respect to their possibilities and limitations. Drying is highly discouraged, because it causes unpredictable structures and artefacts. Staining preserves the structure better, but inner details are obscured. Although one should be aware of artefacts such as ice contamination, cryo-electron microscopy is the method of choice.
- Polyanion-Type Electrode Materials for Sodium-Ion Batteries
Authors: Qiao Ni; Ying Bai, Feng Wu, Chuan Wu
Abstract: Sodium-ion batteries, representative members of the post-lithium-battery club, are very attractive and promising for large-scale energy storage applications. The increasing technological improvements in sodium-ion batteries (Na-ion batteries) are being driven by the demand for Na-based electrode materials that are resource-abundant, cost-effective, and long lasting. Polyanion-type compounds are among the most promising electrode materials for Na-ion batteries due to their stability, safety, and suitable operating voltages. The most representative polyanion-type electrode materials are Na3V2(PO4)3 and NaTi2(PO4)3 for Na-based cathode and anode materials, respectively. Both show superior electrochemical properties and attractive prospects in terms of their development and application in Na-ion batteries. Carbonophosphate Na3MnCO3PO4 and amorphous FePO4 have also recently emerged and are contributing to further developing the research scope of polyanion-type Na-ion batteries. However, the typical low conductivity and relatively low capacity performance of such materials still restrict their development. This paper presents a brief review of the research progress of polyanion-type electrode materials for Na-ion batteries, summarizing recent accomplishments, highlighting emerging strategies, and discussing the remaining challenges of such systems.Polyanion-type electrode materials, combining the advantages of stability, safety and suitable operating voltages, are promising electrode candidates for sodium-ion batteries aiming at large-scale electrochemical energy storage. This article summarizes recent research into different types of these materials. The existing challenges and prospective strategies are also proposed and discussed.
- High-Density Microporous Li4Ti5O12 Microbars with Superior Rate
Performance for Lithium-Ion Batteries
Authors: Linkai Tang; Yan-Bing He, Chao Wang, Shuan Wang, Marnix Wagemaker, Baohua Li, Quan-Hong Yang, Feiyu Kang
Abstract: Nanosized Li4Ti5O12 (LTO) materials enabling high rate performance suffer from a large specific surface area and low tap density lowering the cycle life and practical energy density. Microsized LTO materials have high density which generally compromises their rate capability. Aiming at combining the favorable nano and micro size properties, a facile method to synthesize LTO microbars with micropores created by ammonium bicarbonate (NH4HCO3) as a template is presented. The compact LTO microbars are in situ grown by spinel LTO nanocrystals. The as-prepared LTO microbars have a very small specific surface area (6.11 m2 g−1) combined with a high ionic conductivity (5.53 × 10−12 cm−2 s−1) and large tap densities (1.20 g cm−3), responsible for their exceptionally stable long-term cyclic performance and superior rate properties. The specific capacity reaches 141.0 and 129.3 mAh g−1 at the current rate of 10 and 30 C, respectively. The capacity retention is as high as 94.0% and 83.3% after 500 and 1000 cycles at 10 C. This work demonstrates that, in situ creating micropores in microsized LTO using NH4HCO3 not only facilitates a high LTO tap density, to enhance the volumetric energy density, but also provides abundant Li-ion transportation channels enabling high rate performance.Compact microsized Li4Ti5O12 (LTO) microbars with rich micropores are prepared using ammonium bicarbonate (NH4HCO3) as a micropores created template. The LTO microbars are in situ grown by spinel LTO nanocrystals, which have tiny specific area, high ionic conductivity, and tap density in combination with exceptionally stable long-term cyclic performance and superior rate properties.
- Tumor Microenvironment Activable Self-Assembled DNA Hybrids for pH and
Redox Dual-Responsive Chemotherapy/PDT Treatment of Hepatocellular
Authors: Da Zhang; Aixian Zheng, Juan Li, Ming Wu, Zhixiong Cai, Lingjie Wu, Zuwu Wei, Huanghao Yang, Xiaolong Liu, Jingfeng Liu
Abstract: Smart self-assembled “Turn-ON” DNA hybrids are employed, which could respond to tumor microenvironment stimuli for cancer cell specific real-time fluorescence imaging, tumor-specific synergistic photodynamic therapy and chemotherapy in hepatocellular carcinoma.
- Porous Ionic Membrane Based Flexible Humidity Sensor and its
Authors: Tie Li; Lianhui Li, Hongwei Sun, Yan Xu, Xuewen Wang, Hui Luo, Zheng Liu, Ting Zhang
Abstract: A highly flexible porous ionic membrane (PIM) is fabricated from a polyvinyl alcohol/KOH polymer gel electrolyte, showing well-defined 3D porous structure. The conductance of the PIM changes more than 70 times as the relative humidity (RH) increases from 10.89% to 81.75% with fast and reversible response at room temperature. In addition, the PIM-based sensor is insensitive to temperature (0–95 °C) and pressure (0–6.8 kPa) change, which indicates that it can be used as highly selective flexible humidity sensor. A noncontact switch system containing PIM-based sensor is assembled, and results show that the switch responds favorably to RH change caused by an approaching finger. Moreover, an attachable smart label using PIM-based sensor is explored to measure the water contents of human skin, which shows a great linear relationship between the sensitivity of the sensor and the facial water contents measured by a commercial reference device.A novel temperature and pressure insensitive flexible humidity sensor is fabricated from the porous ionic membrane (PIM), showing fast and reversible response to relative humidity increases from 10.89% to 81.75%. A noncontact switch system responded to finger approaching and the possibility of measuring the water content of human skin are demonstrated in detail on the basis of this PIM sensor.
- Graphene-Based Polymer Bilayers with Superior Light-Driven Properties for
Remote Construction of 3D Structures
Authors: Zhenhua Tang; Ziwei Gao, Shuhai Jia, Fei Wang, Yonglin Wang
Abstract: 3D structure assembly in advanced functional materials is important for many areas of technology. Here, a new strategy exploits IR light-driven bilayer polymeric composites for autonomic origami assembly of 3D structures. The bilayer sheet comprises a passive layer of poly(dimethylsiloxane) (PDMS) and an active layer comprising reduced graphene oxides (RGOs), thermally expanding microspheres (TEMs), and PDMS. The corresponding fabrication method is versatile and simple. Owing to the large volume expansion of the TEMs, the two layers exhibit large differences in their coefficients of thermal expansion. The RGO-TEM-PDMS/PDMS bilayers can deflect toward the PDMS side upon IR irradiation via the cooperative effect of the photothermal effect of the RGOs and the expansion of the TEMs, and exhibit excellent light-driven, a large bending deformation, and rapid responsive properties. The proposed RGO-TEM-PDMS/PDMS composites with excellent light-driven bending properties are demonstrated as active hinges for building 3D geometries such as bidirectionally folded columns, boxes, pyramids, and cars. The folding angle (ranging from 0° to 180°) is well-controlled by tuning the active hinge length. Furthermore, the folded 3D architectures can permanently preserve the deformed shape without energy supply. The presented approach has potential in biomedical devices, aerospace applications, microfluidic devices, and 4D printing.Light-driven construction of 3D structures in graphene-based bilayer sheets are proposed. The bilayer (reduced graphene oxide-thermally expanding microspheres-poly(dimethylsiloxane) (PDMS)/PDMS) can be driven by IR irradiation owing to the photothermal effect of graphene and the asymmetric expansion of the bilayer structures. The bimorph sheets are used as hinges for fabricating 3D objects and exhibit potential applications in biomedical engineering and aerospace.
- Sodium-Ion Batteries: Improving the Rate Capability of 3D Interconnected
Carbon Nanofibers Thin Film by Boron, Nitrogen Dual-Doping
Authors: Min Wang; Yang Yang, Zhenzhong Yang, Lin Gu, Qianwang Chen, Yan Yu
Abstract: Boron, nitrogen dual-doping 3D hard carbon nanofibers thin film is synthesized using a facile process. The nanofibers exhibit high specific capacity and remarkable high-rate capability due to the synergistic effect of 3D porous structure, large surface area, and enlarged carbon layer spacing, and the B, N codoping-induced defects.
- Highly Active and Stable Pt–Pd Alloy Catalysts Synthesized by
Room-Temperature Electron Reduction for Oxygen Reduction Reaction
Authors: Wei Wang; Zongyuan Wang, Jiajun Wang, Chuan-Jian Zhong, Chang-Jun Liu
Abstract: Carbon-supported platinum (Pt) and palladium (Pd) alloy catalyst has become a promising alternative electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. In this work, the synthesis of highly active and stable carbon-supported Pt–Pd alloy catalysts is reported with a room-temperature electron reduction method. The alloy nanoparticles thus prepared show a particle size around 2.6 nm and a core–shell structure with Pt as the shell. With this structure, the breaking of O–O bands and desorption of OH are both promoted in electrocatalysis of ORR. In comparison with the commercial Pt/C catalyst prepared by conventional method, the mass activity of the Pt–Pd/C catalyst for ORR is shown to increase by a factor of ≈4. After 10 000-cycle durability test, the Pt–Pd/C catalyst is shown to retain 96.5% of the mass activity, which is much more stable than that of the commercial Pt/C catalyst.Highly active and stable Pt–Pd alloy catalysts have been developed for oxygen reduction reaction (ORR). The catalysts are synthesized via a novel “low-temperature conversion” method. The as-prepared catalysts exhibit a particle size around 2.6 nm and a core–shell structure with Pt as the shell. With this structure, the Pt–Pd alloy catalysts show brilliant ORR activities and stabilities.
- Carbon Nanotubes in TiO2 Nanofiber Photoelectrodes for High-Performance
Perovskite Solar Cells
Authors: Munkhbayar Batmunkh; Thomas J. Macdonald, Cameron J. Shearer, Munkhjargal Bat-Erdene, Yun Wang, Mark J. Biggs, Ivan P. Parkin, Thomas Nann, Joseph G. Shapter
Abstract: 1D semiconducting oxides are unique structures that have been widely used for photovoltaic (PV) devices due to their capability to provide a direct pathway for charge transport. In addition, carbon nanotubes (CNTs) have played multifunctional roles in a range of PV cells because of their fascinating properties. Herein, the influence of CNTs on the PV performance of 1D titanium dioxide nanofiber (TiO2 NF) photoelectrode perovskite solar cells (PSCs) is systematically explored. Among the different types of CNTs, single-walled CNTs (SWCNTs) incorporated in the TiO2 NF photoelectrode PSCs show a significant enhancement (≈40%) in the power conversion efficiency (PCE) as compared to control cells. SWCNTs incorporated in TiO2 NFs provide a fast electron transfer within the photoelectrode, resulting in an increase in the short-circuit current (Jsc) value. On the basis of our theoretical calculations, the improved open-circuit voltage (Voc) of the cells can be attributed to a shift in energy level of the photoelectrodes after the introduction of SWCNTs. Furthermore, it is found that the incorporation of SWCNTs into TiO2 NFs reduces the hysteresis effect and improves the stability of the PSC devices. In this study, the best performing PSC device constructed with SWCNT structures achieves a PCE of 14.03%.Perovskite light absorber-based photovoltaic cells have gained significant attention over the past few years due to their high performance. Herein, the successful incorporation of highly conductive carbon nanotubes into 1D TiO2 nanofiber-based photoelectrodes for highly efficient and stable PSCs is demonstrated.
- Phosphate Framework Electrode Materials for Sodium Ion Batteries
Authors: Yongjin Fang; Jiexin Zhang, Lifen Xiao, Xinping Ai, Yuliang Cao, Hanxi Yang
Abstract: Sodium ion batteries (SIBs) have been considered as a promising alternative for the next generation of electric storage systems due to their similar electrochemistry to Li-ion batteries and the low cost of sodium resources. Exploring appropriate electrode materials with decent electrochemical performance is the key issue for development of sodium ion batteries. Due to the high structural stability, facile reaction mechanism and rich structural diversity, phosphate framework materials have attracted increasing attention as promising electrode materials for sodium ion batteries. Herein, we review the latest advances and progresses in the exploration of phosphate framework materials especially related to single-phosphates, pyrophosphates and mixed-phosphates. We provide the detailed and comprehensive understanding of structure–composition–performance relationship of materials and try to show the advantages and disadvantages of the materials for use in SIBs. In addition, some new perspectives about phosphate framework materials for SIBs are also discussed. Phosphate framework materials will be a competitive and attractive choice for use as electrodes in the next-generation of energy storage devices.Phosphate framework materials have attracted increasing attention as promising electrode materials for sodium ion batteries. The latest advances and progresses in the exploration of phosphate framework materials are reviewed, especially in relation to single-phosphates, pyrophosphates and mixed-phosphates. Phosphate framework materials will be a competitive and attractive choice for use as electrodes in the next-generation of energy storage devices.
- Recent Progress in Metal-Organic Frameworks for Applications in
Electrocatalytic and Photocatalytic Water Splitting
Authors: Wei Wang; Xiaomin Xu, Wei Zhou, Zongping Shao
Abstract: The development of clean and renewable energy materials as alternatives to fossil fuels is foreseen as a potential solution to the crucial problems of environmental pollution and energy shortages. Hydrogen is an ideal energy material for the future, and water splitting using solar/electrical energy is one way to generate hydrogen. Metal-organic frameworks (MOFs) are a class of porous materials with unique properties that have received rapidly growing attention in recent years for applications in water splitting due to their remarkable design flexibility, ultra-large surface-to-volume ratios and tunable pore channels. This review focuses on recent progress in the application of MOFs in electrocatalytic and photocatalytic water splitting for hydrogen generation, including both oxygen and hydrogen evolution. It starts with the fundamentals of electrocatalytic and photocatalytic water splitting and the related factors to determine the catalytic activity. The recent progress in the exploitation of MOFs for water splitting is then summarized, and strategies for designing MOF-based catalysts for electrocatalytic and photocatalytic water splitting are presented. Finally, major challenges in the field of water splitting are highlighted, and some perspectives of MOF-based catalysts for water splitting are proposed.Metal-organic frameworks (MOFs) as a class of porous materials have received growing attention these years for their applications in catalyzing the electrocatalytic and photocatalytic water splitting reactions. Recent progress in the exploitation of MOFs toward water splitting reactions is reviewed with highlights in the rational design of highly efficient MOF-based catalysts. The perspectives for future research are also outlined.
- Recent Progress in Energy-Driven Water Splitting
Authors: Si Yin Tee; Khin Yin Win, Wee Siang Teo, Leng-Duei Koh, Shuhua Liu, Choon Peng Teng, Ming-Yong Han
Abstract: Hydrogen is readily obtained from renewable and non-renewable resources via water splitting by using thermal, electrical, photonic and biochemical energy. The major hydrogen production is generated from thermal energy through steam reforming/gasification of fossil fuel. As the commonly used non-renewable resources will be depleted in the long run, there is great demand to utilize renewable energy resources for hydrogen production. Most of the renewable resources may be used to produce electricity for driving water splitting while challenges remain to improve cost-effectiveness. As the most abundant energy resource, the direct conversion of solar energy to hydrogen is considered the most sustainable energy production method without causing pollutions to the environment. In overall, this review briefly summarizes thermolytic, electrolytic, photolytic and biolytic water splitting. It highlights photonic and electrical driven water splitting together with photovoltaic-integrated solar-driven water electrolysis.Energy-driven hydrogen production via water splitting with thermal, electrical, photonic and biochemical energy and their combined forms such as thermoelectrolysis, biophotolysis, and photoelectrolysis are summarized in this review. There are focuses on recent advances in water splitting with the use of renewable energy for photocatalytic and electrocatalytic hydrogen production such as photovoltaic-integrated solar driven water electrolysis.
- Self-Assembled Bifunctional Peptide as Effective Drug Delivery Vector with
Powerful Antitumor Activity
Authors: Rangrang Fan; Lan Mei, Xiang Gao, Yuelong Wang, Mingli Xiang, Yu Zheng, Aiping Tong, Xiaoning Zhang, Bo Han, Liangxue Zhou, Peng Mi, Chao You, Zhiyong Qian, Yuquan Wei, Gang Guo
Abstract: E-cadherin/catenin complex is crucial for cancer cell migration and invasion. The histidine-alanine-valine (HAV) sequence has been shown to inhibit a variety of cadherin-based functions. In this study, by fusing HAV and the classical tumor-targeting Arg-Gly-Asp (RGD) motif and Asn-Gly-Arg (NGR) motif to the apoptosis-inducing peptide sequence-AVPIAQK, a bifunctional peptide has been constructed with enhanced tumor targeting and apoptosis effects. This peptide is further processed as a nanoscale vector to encapsulate the hydrophobic drug docetaxel (DOC). Bioimaging analysis shows that peptide nanoparticles can penetrate into xenograft tumor cells with a significantly long retention in tumors and high tumor targeting specificity. In vivo, DOC/peptide NPs are substantially more effective at inhibiting tumor growth and prolonging survival compared with DOC control. Together, the findings of this study suggest that DOC/peptide NPs may have promising applications in pulmonary carcinoma therapy.A self-assembled bifunctional peptide (HRK-19)-based docetaxel loaded nanoparticle is developed. HRK-19 peptide, is conjugated with bifunctional tumor targeting peptide sequences—NGRRGD and histidine-alanine-valine—and apoptosis-inducing peptide sequence—AVPIAQK. These docetaxel/peptide nanoparticles can target to the tumor cells, induce apoptosis of tumor cells by apoptosis-inducing peptide AVPIAQK and docetaxel, and successfully inhibit tumor growth of mice.
- The Mechanical Properties of Nanowires
Authors: Shiliang Wang; Zhiwei Shan, Han Huang
Abstract: Applications of nanowires into future generation nanodevices require a complete understanding of the mechanical properties of the nanowires. A great research effort has been made in the past two decades to understand the deformation physics and mechanical behaviors of nanowires, and to interpret the discrepancies between experimental measurements and theoretical predictions. This review focused on the characterization and understanding of the mechanical properties of nanowires, including elasticity, plasticity, anelasticity and strength. As the results from the previous literature in this area appear inconsistent, a critical evaluation of the characterization techniques and methodologies were presented. In particular, the size effects of nanowires on the mechanical properties and their deformation mechanisms were discussed.Mechanical properties of nanowires play an important role on their applications in future generation nanodevices. This critical review assesses the recent development on characterizing and understanding the mechanical properties of nanowires, including elasticity, plasticity, anelasticity and strength. The size effects on the mechanical properties of nanowires are summarized and discussed, and the prospects for future investigations are also outlined.
- Thermally Activated Delayed Fluorescence Organic Dots (TADF Odots) for
Time-Resolved and Confocal Fluorescence Imaging in Living Cells and In
Authors: Tingting Li; Dongliang Yang, Liuqing Zhai, Suiliang Wang, Baomin Zhao, Nina Fu, Lianhui Wang, Youtian Tao, Wei Huang
Abstract: The fluorophores with long-lived fluorescent emission are highly desirable for time-resolved fluorescence imaging (TRFI) in monitoring target fluorescence. By embedding the aggregates of a thermally activated delayed fluorescence (TADF) dye, 2,3,5,6-tetracarbazole-4-cyano-pyridine (CPy), in distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol) (DSPE-PEG2000) matrix, CPy-based organic dots (CPy-Odots) with a long fluorescence lifetime of 9.3 μs (in water at ambient condition) and high brightness (with an absolute fluorescence quantum efficiency of 38.3%) are fabricated. CPy-Odots are employed in time-resolved and confocal fluorescence imaging in living Hela cells and in vivo. The green emission from the CPy-Odots is readily differentiated from the cellular autofluorescence background because of their stronger emission intensities and longer lifetimes. Unlike other widely studied DSPE-PEG2000 encapsulated Odots which are always distributed in cytoplasm, CPy-Odots are located mainly in plasma membrane. In addition, the application of CPy-Odots as a bright microangiography agent for TRFI in zebrafish is also demonstrated. Much broader application of CPy-Odots is also prospected after further surface functionalization. Given its simplicity, high fluorescence intensity, and wide availability of TADF materials, the method can be extended to develop more excellent TADF Odots for accomplishing the challenges in future bioimaging applications.The nanotechnology toward thermally activated delayed fluorescence 2,3,5,6-tetracarbazole-4-cyano-pyridine-organic dots with excellent photostability, low cytotoxicity, and ultrabright luminescence and fluorescent lifetime of 9.3 μs was developed. Utilizing this nanoprobe, its application is successfully realized in time-resolved and confocal fluorescence imaging in vitro and in vivo.
- An Enhanced UV–Vis–NIR an d Flexible Photodetector Based on
Electrospun ZnO Nanowire Array/PbS Quantum Dots Film Heterostructure
Authors: Zhi Zheng; Lin Gan, Jianbing Zhang, Fuwei Zhuge, Tianyou Zhai
Abstract: ZnO nanostructure-based photodetectors have a wide applications in many aspects, however, the response range of which are mainly restricted in the UV region dictated by its bandgap. Herein, UV–vis–NIR sensitive ZnO photodetectors consisting of ZnO nanowires (NW) array/PbS quantum dots (QDs) heterostructures are fabricated through modified electrospining method and an exchanging process. Besides wider response region compared to pure ZnO NWs based photodetectors, the heterostructures based photodetectors have faster response and recovery speed in UV range. Moreover, such photodetectors demonstrate good flexibility as well, which maintain almost constant performances under extreme (up to 180°) and repeat (up to 200 cycles) bending conditions in UV–vis–NIR range. Finally, this strategy is further verified on other kinds of 1D nanowires and 0D QDs, and similar enhancement on the performance of corresponding photodetecetors can be acquired, evidencing the universality of this strategy.UV–vis–NIR photodetector based on electrospun ZnO nanowire array and PbS quantum dots (QDs) thin film heterostructure is fabricated. This heterostructure photodetector exhibits an enhanced response speed and maintains its photoresponse performance via 200 cycles bending. This electrospinning and ligand exchange strategies open up possibilities for UV-Vis-NIR and flexible photodetector in optoelectronic circuitry.
- One-Dimensional Earth-Abundant Nanomaterials for Water-Splitting
Authors: Jun Li; Gengfeng Zheng
Abstract: Hydrogen fuel acquisition based on electrochemical or photoelectrochemical water splitting represents one of the most promising means for the fast increase of global energy need, capable of offering a clean and sustainable energy resource with zero carbon footprints in the environment. The key to the success of this goal is the realization of robust earth-abundant materials and cost-effective reaction processes that can catalyze both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with high efficiency and stability. In the past decade, one-dimensional (1D) nanomaterials and nanostructures have been substantially investigated for their potential in serving as these electrocatalysts for reducing overpotentials and increasing catalytic activity, due to their high electrochemically active surface area, fast charge transport, efficient mass transport of reactant species, and effective release of gas produced. In this review, we summarize the recent progress in developing new 1D nanomaterials as catalysts for HER, OER, as well as bifunctional electrocatalysts for both half reactions. Different categories of earth-abundant materials including metal-based and metal-free catalysts are introduced, with their representative results presented. The challenges and perspectives in this field are also discussed.Exploring new electrocatalysts for water splitting is one main focus of clean hydrogen fuel conversion and utilization. This review summarizes the recent development of one-dimensional earth-abundant nanomaterials, including metal-based or metal-free materials, as catalysts for hydrogen evolution reaction, oxygen evolution reaction, and both. The rational design and preparation of novel electrocatalysts with structure and performance optimization will certainly suggest new opportunities of utilizing hydrogen fuel for global energy requirement.
- Single Crystalline Ultrathin Nickel–Cobalt Alloy Nanosheets Array for
Direct Hydrazine Fuel Cells
Authors: Guang Feng; Yun Kuang, Pengsong Li, Nana Han, Ming Sun, Guoxin Zhang, Xiaoming Sun
Abstract: Ultrathin 2D metal alloy nanomaterials have great potential applications but their controlled syntheses are limited to few noble metal based systems. Herein NixCo1−x alloy nanosheets with ultrathin (sub-3 nm) single-crystalline 2D structure are synthesized through a topochemical reduction method. Moreover, the optimized composition Ni0.6Co0.4 alloy nanosheets array exhibits excellent performances for hydrazine oxidation reaction and direct hydrazine fuel cells.
- Enhancing Oxygen Evolution Reaction at High Current Densities on
Amorphous-Like Ni–Fe–S Ultrathin Nanosheets via Oxygen Incorporation
and Electrochemical Tuning
Authors: Jingfang Zhang; Yuchen Hu, Dali Liu, Yu Yu, Bin Zhang
Abstract: Amorphous-like Ni–Fe–S ultrathin nanosheets by oxygen incorporation and electrochemical tuning show excellent OER activity at high current densities. Such excellent performance could be attributed to the unique 3D porous configuration composed of amorphous-like ultrathin nanosheets with much more active sites and improved conductivity, as well as the proper electronic structure benefiting from the oxygen incorporation and electrochemical tuning.
- A 3D Chemically Modified Graphene Hydrogel for Fast, Highly Sensitive, and
Selective Gas Sensor
Authors: Jin Wu; Kai Tao, Yuanyuan Guo, Zhong Li, Xiaotian Wang, Zhongzhen Luo, Shuanglong Feng, Chunlei Du, Di Chen, Jianmin Miao, Leslie K. Norford
Abstract: Reduced graphene oxide (RGO) has proved to be a promising candidate in high-performance gas sensing in ambient conditions. However, trace detection of different kinds of gases with simultaneously high sensitivity and selectivity is challenging. Here, a chemiresistor-type sensor based on 3D sulfonated RGO hydrogel (S-RGOH) is reported, which can detect a variety of important gases with high sensitivity, boosted selectivity, fast response, and good reversibility. The NaHSO3 functionalized RGOH displays remarkable 118.6 and 58.9 times higher responses to NO2 and NH3, respectively, compared with its unmodified RGOH counterpart. In addition, the S-RGOH sensor is highly responsive to volatile organic compounds. More importantly, the characteristic patterns on the linearly fitted response–temperature curves are employed to distinguish various gases for the first time. The temperature of the sensor is elevated rapidly by an imbedded microheater with little power consumption. The 3D S-RGOH is characterized and the sensing mechanisms are proposed. This work gains new insights into boosting the sensitivity of detecting various gases by combining chemical modification and 3D structural engineering of RGO, and improving the selectivity of gas sensing by employing temperature dependent response characteristics of RGO for different gases.A one-step self-assembled 3D sulfonated reduced graphene oxide hydrogel (S-RGOH) is developed to detect various important gaseous chemicals with high performance. The S-RGOH sensor displays remarkable 118.6 and 58.9 times higher responses to NO2 and NH3, respectively, compared with the unmodified counterpart. An imbedded microheater is employed to differentiate various gases by identifying the characteristic patterns on the fitted response–temperature curves.
- Nanoparticle Functionalization and Its Potentials for Molecular Imaging
Authors: Rukmani Thiruppathi; Sachin Mishra, Mathangi Ganapathy, Parasuraman Padmanabhan, Balázs Gulyás
Abstract: Functionalization enhances the properties and characteristics of nanoparticles through surface modification, and enables them to play a major role in the field of medicine. In molecular imaging, quality functional images are required with proper differentiation which can be seen with high contrast to obtain viable information. This review article discusses how functionalization enhances molecular imaging and enables multimodal imaging by which images with combination of functions particular to each modality can be obtained. This also explains how nanoparticles interacting at molecular level, when functionalized with molecules can target the cells of interest or substances with high specificity, reducing background signal and allowing simultaneous therapies to be carried out while imaging. Functionalization allows imaging for a prolonged period and enables to track the cells over a period of time. Recent researches and progress in functionalizing the nanoparticles to specifically enhance bioimaging with different modalities and their applications are reviewed in this article.Recent approaches and methods of specifically functionalizing nanoparticles to better equip the molecular imaging techniques like confocal and fluorescence microscopy, magnetic resonance imaging, positron emission tomography, and computed tomography are reviewed while providing an overview of chemistry behind functionalization and development of various advanced probe models including theranostics, multimodal imaging, and intraoperative therapies through functionalization.
- Photo-Cross-Linked Dual-Responsive Hollow Capsules Mimicking Cell Membrane
for Controllable Cargo Post-Encapsulation and Release
Authors: Xiaoling Liu; Dietmar Appelhans, Qiang Wei, Brigitte Voit
Abstract: Multifunctional and responsive hollow capsules are ideal candidates to establish highly sophisticated compartments mimicking cell membranes for controllable bio-inspired functions. For this purpose pH and temperature dual-responsive and photo-cross-linked hollow capsules, based on silica-templated layer-by-layer approach by using poly(N-isopropyl acrylamide)-block-polymethacrylate) and polyallylamine, have been prepared to use them for the subsequent and easily available post-encapsulation process of protein-like macromolecules at room temperature and pH 7.4 and their controllable release triggered by stimuli. The uptake and release properties of the hollow capsules for cargos are highly affected by changes in the external stimuli temperature (25, 37, or 45 °C) and internal stimuli pH of the phosphate-containing buffer solution (5.5 or 7.4), by the degree of photo-cross-linking, and the size of cargo. The photo-cross-linked and dual stimuli-responsive hollow capsules with different membrane permeability can be considered as attractive material for mimicking cell functions triggered by controllable uptake and release of different up to 11 nm sized biomolecules.For mimicking cell-like functions membrane permeability of hollow capsules is generally tunable by pH and temperature stimuli in phosphate-containing environment. This allows the controlled post-uptake and release of nanometer-sized cargo (≤11 nm) by/from hollow capsules under mild conditions, combining pH 7.4 or 5.5 with temperature of 25, 37, or 45 °C, usable for purposes in synthetic biology.
- Giant Faraday Rotation through Ultrasmall Fe0n Clusters in
Superparamagnetic FeO-SiO2 Vitreous Films
Authors: Yuko Nakatsuka; Kilian Pollok, Torsten Wieduwilt, Falko Langenhorst, Markus A. Schmidt, Koji Fujita, Shunsuke Murai, Katsuhisa Tanaka, Lothar Wondraczek
Abstract: Magnetooptical (MO) glasses and, in particular, Faraday rotators are becoming key components in lasers and optical information processing, light switching, coding, filtering, and sensing. The common design of such Faraday rotator materials follows a simple path: high Faraday rotation is achieved by maximizing the concentration of paramagnetic ion species in a given matrix material. However, this approach has reached its limits in terms of MO performance; hence, glass-based materials can presently not be used efficiently in thin film MO applications. Here, a novel strategy which overcomes this limitation is demonstrated. Using vitreous films of xFeO·(100 − x)SiO2, unusually large Faraday rotation has been obtained, beating the performance of any other glassy material by up to two orders of magnitude. It is shown that this is due to the incorporation of small, ferromagnetic clusters of atomic iron which are generated in line during laser deposition and rapid condensation of the thin film, generating superparamagnetism. The size of these clusters underbids the present record of metallic Fe incorporation and experimental verification in glass matrices.Giant Faraday rotation is obtained in vitreous films of xFeO·(100 − x)SiO2, beating the performance of any other glassy material by up to two orders of magnitude. The effect is related to the incorporation of ferromagnetic clusters of atomic iron. The size of these clusters underbids the present record of metallic Fe incorporation and experimental verification in glass matrices.
- Revelation of Interfacial Energetics in Organic Multiheterojunctions
Authors: Christian Kästner; Koen Vandewal, Daniel Ayuk Mbi Egbe, Harald Hoppe
Abstract: Efficient charge generation via exciton dissociation in organic bulk heterojunctions necessitates donor–acceptor interfaces, e.g., between a conjugated polymer and a fullerene derivative. Furthermore, aggregation and corresponding structural order of polymer and fullerene domains result in energetic relaxations of molecular energy levels toward smaller energy gaps as compared to the situation for amorphous phases existing in homogeneously intermixed polymer:fullerene blends. Here it is shown that these molecular energy level shifts are reflected in interfacial charge transfer (CT) transitions and depending on the existence of disordered or ordered interfacial domains. It can be done so by systematically controlling the order at the donor–acceptor interface via ternary blending of semicrystalline and amorphous model polymers with a fullerene acceptor. These variations in interfacial domain order are probed with luminescence spectroscopy, yielding various transition energies due to activation of different recombination channels at the interface. Finally, it is shown that via this analysis the energy landscape at the organic heterojunction interface can be obtained.Efficient charge generation via exciton dissociation in organic bulk heterojunctions necessitates donor–acceptor interfaces. It is shown that their energy landscape is reflected in interfacial charge transfer transitions, probed via luminescence spectroscopy, and depended on the existence of disordered/ordered interfacial domains, which are experimentally applied by ternary blending of amorphous and semicrystalline polymer, in various ratios, with fullerenes.
- Light Like a Feather: A Fibrous Natural Composite with a Shape Changing
from Round to Square
Authors: Bin Wang; Marc André Meyers
Abstract: Only seldom are square/rectangular shapes found in nature. One notable exception is the bird feather rachis, which raises the question: why is the proximal base round but the distal end square' Herein, it is uncovered that, given the same area, square cross sections show higher bending rigidity and are superior in maintaining the original shape, whereas circular sections ovalize upon flexing. This circular-to-square shape change increases the ability of the flight feathers to resist flexure while minimizes the weight along the shaft length. The walls are themselves a heterogeneous composite with the fiber arrangements adjusted to the local stress requirements: the dorsal and ventral regions are composed of longitudinal and circumferential fibers, while lateral walls consist of crossed fibers. This natural avian design is ready to be reproduced, and it is anticipated that the knowledge gained from this work will inspire new materials and structures for, e.g., manned/unmanned aerial vehicles.Why is the proximal base of flight feather shaft round but the distal end square' Nature seldom produces square shapes, but the feather rachis is one exception. Here fundamental reasons are provided explaining the unique structural design: the gradient in shape and the varying fiber orientations work synergistically, tailoring the flexural stiffness along the shaft length while minimizing weight.
- Ultrathin Fluidic Laminates for Large-Area Façade Integration and
Authors: Benjamin P. V. Heiz; Zhiwen Pan, Gerhard Lautenschläger, Christin Sirtl, Matthias Kraus, Lothar Wondraczek
Abstract: Buildings represent more than 40% of Europe's energy demands and about one third of its CO2 emissions. Energy efficient buildings and, in particular, building skins have therefore been among the key priorities of international research agendas. Here, glass–glass fluidic devices are presented for large-area integration with adaptive façades and smart windows. These devices enable harnessing and dedicated control of various liquids for added functionality in the building envelope. Combining a microstructured glass pane, a thin cover sheet with tailored mechanical performance, and a liquid for heat storage and transport, a flat-panel laminate is generated with thickness adapted to a single glass sheet in conventional windows. Such multimaterial devices can be integrated with state-of-the-art window glazings or façades to harvest and distribute thermal as well as solar energy by wrapping buildings into a fluidic layer. High visual transparency is achieved through adjusting the optical properties of the employed liquid. Also secondary functionality, such as chromatic windows, polychromatism, or adaptive energy uptake can be generated on part of the liquid.Glass–glass fluidic devices are presented for large-area integration with adaptive façades and smart windows, enabling harnessing and dedicated control of liquids for added functionality in the building envelope by wrapping buildings into a fluidic layer.
- Periodic Mesoporous Organosilica Coated Prussian Blue for MR/PA Dual-Modal
Authors: Wei Tian; Yunyan Su, Ying Tian, Shouju Wang, Xiaodan Su, Ying Liu, Yunlei Zhang, Yuxia Tang, Qianqian Ni, Wenfei Liu, Meng Dang, Chunyan Wang, Junjie Zhang, Zhaogang Teng, Guangming Lu
Abstract: Complete eradication of highly aggressive triple negative breast cancer (TNBC) remains a notable challenge today. In this work, an imaging-guided photothermal-chemotherapy strategy for TNBC is developed for the first time based on a periodic mesoporous organosilica (PMO) coated Prussian blue (PB@PMO) nanoplatform. The PB@PMOs have organic-inorganic hybrid frameworks, uniform diameter (125 nm), high surface area (866 m2 g−1), large pore size (3.2 nm), excellent photothermal conversion capability, high drug loading capacity (260 µg mg−1), and magnetic resonance (MR) and photoacoustic (PA) imaging abilities. The MR and PA properties of the PB@PMOs are helpful for imaging the tumor and showing the accumulation of the nanoplatform in the tumor region. The bioluminescence intensity and tumor volume of the MDA-MB-231-Luc tumor-bearing mouse model demonstrate that TNBC can be effectively inhibited by the combined photothermal-chemotherapy than monotherapy strategy. Histopathological analysis further reveals that the combination therapy results in most extensive apoptotic and necrotic cells in the tumor without inducing obvious side effect to major organs.Periodic mesoporous organosilica (PMO) coated Prussian blue (PB) is successfully synthesized for the first time. The PB@PMO nanoparticles have organic–inorganic hybrid framework, uniform size, high surface area, uniform pore size, excellent photothermal conversion capacity, good biocompatibility, and high drug loading capability with a pH-responsive drug release. Utilizing the nanoplatforms, dual-modal magnetic resonance and photoacoustic imaging-guided photothermal-chemotherapy has achieved encouraging therapeutic outcomes for triple negative breast cancer.