bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Stretchable Conductive Glue for High‐Performance Silicon Anodes in Advanced Lithium‐Ion Batteries
Authors: Wang Lei , Liu Tiefeng , Peng Xiang , Zeng Wenwu , Jin Zhenzhen , Tian Weifeng , Gao Biao , Zhou Yinhua , Chu Paul K. , Huo Kaifu 
Published: November 2017

AbstractBinder plays a key role in maintaining the mechanical integrity of electrodes in lithium‐ion batteries. However, the existing binders typically exhibit poor stretchability or low conductivity at large strains, which are not suitable for high‐capacity silicon (Si)‐based anodes undergoing severe volume changes during cycling. Herein, a novel stretchable conductive glue (CG) polymer that possesses inherent high conductivity, excellent stretchablity, and ductility is designed for high‐performance Si anodes. The CG can be stretched up to 400% in volume without conductivity loss and mechanical fracture and thus can accommodate the large volume change of Si nanoparticles to maintain the electrode integrity and stabilize solid electrolyte interface growth during cycling while retaining the high conductivity, even with a high Si mass loading of 90%. The Si‐CG anode has a large reversible capacity of 1500 mA h g−1 for over 700 cycles at 840 mA g−1 with a large initial Coulombic efficiency of 80% and high rate capability of 737 mA h g−1 at 8400 mA g−1. Moreover, the Si‐CG anode demonstrates the highest achieved areal capacity of 5.13 mA h cm−2 at a high mass loading of 2 mg cm−2. The highly stretchable CG provides a new perspective for designing next‐generation high‐capacity and high‐power batteries.
Toward High Performance Thiophene‐Containing Conjugated Microporous Polymer Anodes for Lithium‐Ion Batteries through Structure Design
Authors: Zhang Chong , He Yongwu , Mu Pan , Wang Xue , He Qian , Chen Yu , Zeng Jinghui , Wang Feng , Xu Yunhua , Jiang Jia‐Xing 
Published: November 2017

AbstractPoly(thiophene) as a kind of n‐doped conjugated polymer with reversible redox behavior can be employed as anode material for lithium‐ion batteries (LIBs). However, the low redox activity and poor rate performance for the poly(thiophene)‐based anodes limit its further development. Herein, a structure‐design strategy is reported for thiophene‐containing conjugated microporous polymers (CMPs) with extraordinary electrochemical performance as anode materials in LIBs. The comparative study on the electrochemical performance of the structure‐designed thiophene‐containing CMPs reveals that high redox‐active thiophene content, highly crosslinked porous structure, and improved surface area play significant roles for enhancing electrochemical performances of the resulting CMPs. The all‐thiophene‐based polymer of poly(3,3′‐bithiophene) with crosslinked structure and a high surface area of 696 m2 g−1 exhibits a discharge capacity of as high as 1215 mAh g−1 at 45 mA g−1, excellent rate capability, and outstanding cycling stability with a capacity retention of 663 mAh g−1 at 500 mA g−1 after 1000 cycles. The structure–performance relationships revealed in this work offer a fundamental understanding in the rational design of CMPs anode materials for high performance LIBs.
Hydrogel Encapsulation Facilitates Rapid‐Cooling Cryopreservation of Stem Cell‐Laden Core–Shell Microcapsules as Cell–Biomaterial Constructs
Authors: Zhao Gang , Liu Xiaoli , Zhu Kaixuan , He Xiaoming 
Published: November 2017

AbstractCore–shell structured stem cell microencapsulation in hydrogel has wide applications in tissue engineering, regenerative medicine, and cell‐based therapies because it offers an ideal immunoisolative microenvironment for cell delivery and 3D culture. Long‐term storage of such microcapsules as cell–biomaterial constructs by cryopreservation is an enabling technology for their wide distribution and ready availability for clinical transplantation. However, most of the existing studies focus on cryopreservation of single cells or cells in microcapsules without a core–shell structure (i.e., hydrogel beads). The goal of this study is to achieve cryopreservation of stem cells encapsulated in core–shell microcapsules as cell–biomaterial constructs or biocomposites. To this end, a capillary microfluidics‐based core–shell alginate hydrogel encapsulation technology is developed to produce porcine adipose‐derived stem cell‐laden microcapsules for vitreous cryopreservation with very low concentration (2 mol L−1) of cell membrane penetrating cryoprotective agents (CPAs) by suppressing ice formation. This may provide a low‐CPA and cost‐effective approach for vitreous cryopreservation of “ready‐to‐use” stem cell–biomaterial constructs, facilitating their off‐the‐shelf availability and widespread applications.
Polyhedral 30‐Faceted BiVO4 Microcrystals Predominantly Enclosed by High‐Index Planes Promoting Photocatalytic Water‐Splitting Activity
Authors: Li Ping , Chen Xingyu , He Huichao , Zhou Xin , Zhou Yong , Zou Zhigang 
Published: November 2017

AbstractUnprecedented 30‐faceted BiVO4 polyhedra predominantly surrounded by {132}, {321}, and {121} high‐index facets are fabricated through the engineering of high‐index surfaces by a trace amount of Au nanoparticles. The growth of high‐index facets results in a 3–5 fold enhancement of O2 evolution from photocatalytic water splitting by the BiVO4 polyhedron, relative to its low‐index counterparts. Theory calculations reveal that water dissociation is more energetically favorable on the high‐index surfaces than on the low‐index (010), (110), and (101) surfaces, which is accompanied by a notable reduction in the overpotential (0.77–1.14 V) for the oxygen evolution reaction. The apparent quantum efficiency of O2 generation without an external electron supply reaches 18.3% under 430 nm light irradiation, which is an order of magnitude higher than that of the catalysts reported hitherto.
Liquid‐Phase Transmission Electron Microscopy for Studying Colloidal Inorganic Nanoparticles
Authors: Kim Byung Hyo , Yang Jiwoong , Lee Donghoon , Choi Back Kyu , Hyeon Taeghwan , Park Jungwon 
Published: November 2017

AbstractFor the past few decades, nanoparticles of various sizes, shapes, and compositions have been synthesized and utilized in many different applications. However, due to a lack of analytical tools that can characterize structural changes at the nanoscale level, many of their growth and transformation processes are not yet well understood. The recently developed technique of liquid‐phase transmission electron microscopy (TEM) has gained much attention as a new tool to directly observe chemical reactions that occur in solution. Due to its high spatial and temporal resolution, this technique is widely employed to reveal fundamental mechanisms of nanoparticle growth and transformation. Here, the technical developments for liquid‐phase TEM together with their application to the study of solution‐phase nanoparticle chemistry are summarized. Two types of liquid cells that can be used in the high‐vacuum conditions required by TEM are discussed, followed by recent in situ TEM studies of chemical reactions of colloidal nanoparticles. New findings on the growth mechanism, transformation, and motion of nanoparticles are subsequently discussed in detail.
Metal–Organic Frameworks as Platforms for Catalytic Applications
Authors: Jiao Long , Wang Yang , Jiang Hai‐Long , Xu Qiang 
Published: November 2017

AbstractMetal–organic frameworks (MOFs), also called porous coordination polymers, represent a class of crystalline porous materials built from organic linkers and metal ions/clusters. The unique features of MOFs, including structural diversity and tailorability as well as high surface area, etc., enable them to be a highly versatile platform for potential applications in many fields. Herein, an overview of recent developments achieved in MOF catalysis, including heterogeneous catalysis, photocatalysis, and eletrocatalysis over MOFs and MOF‐based materials, is provided. The active sites involved in the catalysts are particularly emphasized. The challenges, future trends, and prospects associated with MOFs and their related materials for catalysis are also discussed.
Redox Mediators for Li–O2 Batteries: Status and Perspectives
Authors: Park Jin‐Bum , Lee Seon Hwa , Jung Hun‐Gi , Aurbach Doron , Sun Yang‐Kook 
Published: November 2017

AbstractLi–O2 batteries have received much attention due to their extremely large theoretical energy density. However, the high overpotentials required for charging Li–O2 batteries lower their energy efficiency and degrade the electrolytes and carbon electrodes. This problem is one of the main obstacles in developing practical Li–O2 batteries. To solve this problem, it is important to facilitate the oxidation of Li2O2 upon charging by using effective electrocatalysis. Using solid catalysts is not too effective for oxidizing the electronically isolating Li‐peroxide layers. In turn, for soluble catalysts, red‐ox mediators (RMs) are homogeneously dissolved in the electrolyte solutions and can effectively oxidize all of the Li2O2 precipitated during discharge. RMs can decompose solid Li2O2 species no matter their size, morphology, or thickness and thus dramatically increase energy efficiency. However, some negative side effects, such as the shuttle reactions of RMs and deterioration of the Li‐metal occur. Therefore, it is necessary to study the activity and stability of RMs in Li–O2 batteries in detail. Herein, recent studies related to redox mediators are reviewed and the mechanisms of redox reactions are illustrated. The development opportunities of RMs for this important battery technology are discussed and future directions are suggested.
Ultrathin 2D Photocatalysts: Electronic‐Structure Tailoring, Hybridization, and Applications
Authors: Di Jun , Xiong Jun , Li Huaming , Liu Zheng 
Published: November 2017

AbstractAs a sustainable technology, semiconductor photocatalysis has attracted considerable interest in the past several decades owing to the potential to relieve or resolve energy and environmental‐pollution issues. By virtue of their unique structural and electronic properties, emerging ultrathin 2D materials with appropriate band structure show enormous potential to achieve efficient photocatalytic performance. Here, the state‐of‐the‐art progress on ultrathin 2D photocatalysts is reviewed and a critical appraisal of the classification, controllable synthesis, and formation mechanism of ultrathin 2D photocatalysts is presented. Then, different strategies to tailor the electronic structure of ultrathin 2D photocatalysts are summarized, including component tuning, thickness tuning, doping, and defect engineering. Hybridization with the introduction of a foreign component and maintaining the ultrathin 2D structure is presented to further boost the photocatalytic performance, such as quantum dots/2D materials, single atoms/2D materials, molecular/2D materials, and 2D–2D stacking materials. More importantly, the advancement of versatile photocatalytic applications of ultrathin 2D photocatalysts in the fields of water oxidation, hydrogen evolution, CO2 reduction, nitrogen fixation, organic syntheses, and removal pollutants is discussed. Finally, the future opportunities and challenges regarding ultrathin 2D photocatalysts to bring about new opportunities for future research in the field of photocatalysis are also presented.
Printing Semiconductor–Insulator Polymer Bilayers for High‐Performance Coplanar Field‐Effect Transistors
Authors: Bu Laju , Hu Mengxing , Lu Wanlong , Wang Ziyu , Lu Guanghao 
Published: November 2017

AbstractSource–semiconductor–drain coplanar transistors with an organic semiconductor layer located within the same plane of source/drain electrodes are attractive for next‐generation electronics, because they could be used to reduce material consumption, minimize parasitic leakage current, avoid cross‐talk among different devices, and simplify the fabrication process of circuits. Here, a one‐step, drop‐casting‐like printing method to realize a coplanar transistor using a model semiconductor/insulator [poly(3‐hexylthiophene) (P3HT)/polystyrene (PS)] blend is developed. By manipulating the solution dewetting dynamics on the metal electrode and SiO2 dielectric, the solution within the channel region is selectively confined, and thus make the top surface of source/drain electrodes completely free of polymers. Subsequently, during solvent evaporation, vertical phase separation between P3HT and PS leads to a semiconductor–insulator bilayer structure, contributing to an improved transistor performance. Moreover, this coplanar transistor with semiconductor–insulator bilayer structure is an ideal system for injecting charges into the insulator via gate‐stress, and the thus‐formed PS electret layer acts as a “nonuniform floating gate” to tune the threshold voltage and effective mobility of the transistors. Effective field‐effect mobility higher than 1 cm2 V−1 s−1 with an on/off ratio > 107 is realized, and the performances are comparable to those of commercial amorphous silicon transistors. This coplanar transistor simplifies the fabrication process of corresponding circuits.
High‐Pressure‐Induced Comminution and Recrystallization of CH3NH3PbBr3 Nanocrystals as Large Thin Nanoplates
Authors: Yin Tingting , Fang Yanan , Chong Wee Kiang , Ming Koh Teck , Jiang Shaojie , Li Xianglin , Kuo Jer‐Lai , Fang Jiye , Sum Tze Chien , White Timothy J. , Yan Jiaxu , Shen Ze Xiang 
Published: November 2017

AbstractHigh pressure (HP) can drive the direct sintering of nanoparticle assemblies for Ag/Au, CdSe/PbS nanocrystals (NCs). Instead of direct sintering for the conventional nanocrystals, this study experimentally observes for the first time high‐pressure‐induced comminution and recrystallization of organic–inorganic hybrid perovskite nanocrystals into highly luminescent nanoplates with a shorter carrier lifetime. Such novel pressure response is attributed to the unique structural nature of hybrid perovskites under high pressure: during the drastic cubic–orthorhombic structural transformation at ≈2 GPa, (301) the crystal plane fully occupied by organic molecules possesses a higher surface energy, triggering the comminution of nanocrystals into nanoslices along such crystal plane. Beyond bulk perovskites, in which pressure‐induced modifications on crystal structures and functional properties will disappear after pressure release, the pressure‐formed variants, i.e., large (≈100 nm) and thin (<10 nm) perovskite nanoplates, are retained and these exhibit simultaneous photoluminescence emission enhancing (a 15‐fold enhancement in the photoluminescence) and carrier lifetime shortening (from ≈18.3 ± 0.8 to ≈7.6 ± 0.5 ns) after releasing of pressure from 11 GPa. This pressure‐induced comminution of hybrid perovskite NCs and a subsequent amorphization–recrystallization treatment offer the possibilities of engineering the advanced hybrid perovskites with specific properties.
Exploration of Chirality and Achirality of Self‐Assembled Monolayer Formed by Unsymmetrically Substituted Fluorenone Derivative at the Liquid/Solid Interface
Authors: Hu Yi , Miao Kai , Dong Meiqiu , Xu Li , Zha Bao , Miao Xinrui , Deng Wenli 
Published: November 2017

AbstractThe self‐assemblies of 2‐decyloxy‐7‐pentadecyloxy‐9‐fluorenone (DPF) are characterized by scanning tunneling microscopy at the liquid/solid interface. Achiral Dimer and chiral S‐like structures are observed in 1‐octanoic acid. The solvent molecule takes part in the self‐assembly via forming COOH⋯OC and COOH⋯COOH hydrogen bonds. When 1‐phenyloctane and n‐tetradecane are used as the solvents, DPF self‐assembles into chiral Z‐like structure, which are classified into Types I–IV according to the packing styles. For the purpose of exploring the effect of solvent and the competition between these three structures, the self‐assemblies of DPF in mixed solvents and on dry surface are investigated. The results show that S‐like structure is preferred in mixed solvents, while the Z‐like structure has priority when the function of solvent is excluded. DPF molecule shows polarity thus dipole−dipole interaction plays significant roles on forming stable adlayers by forming antiparallel dipole pairs. Furthermore, density functional theory calculation is performed to reveal the driving forces of hydrogen bonds and van der Waals interactions. In light of the popularity of studying chirality at the liquid/solid interface, it is believed that the findings will provide implications for designing chiral systems and will promote the exploration of self‐assembly in the field of surface science.
Graphene Oxide Epoxy (GO‐xy): GO as Epoxy Adhesive by Interfacial Reaction of Functionalities
Authors: Vinod Soumya , Tiwary Chandra Sekhar , Samanta Atanu , Ozden Sehmus , Narayanan Tharangattu N. , Vajtai Robert , Agarwal Vipin , Singh Abhishek K. , John George , Ajayan Pulickel M. 
Published: November 2017

AbstractThe unique combination of layered structure and chemical moieties grants very interesting physiochemical properties to graphene oxide (GO). Functional groups such as epoxide, hydroxyl, and carboxyl are abundantly distributed along the hexagonal lattice of carbon atoms. The superior properties of GO and increased interfacial interaction with other compounds make them excellent filler materials in polymers such as epoxies for creating multifunctional composites. Alternatively, the presence of epoxide group on GO opens up the possibility of using it as the major epoxy matrix constituent rather than just as a filler material. In this work, the formation of GO‐xy (cross‐linked GO via the epoxide functionality) resin is reported by reaction of GO with polymercaptan‐based hardener by completely eliminating the need for conventional epoxy component. Substituting epoxy with GO marks notable advance in preparing adhesive materials with high temperature stability.
A Hybrid Piezoelectric and Triboelectric Nanogenerator with PVDF Nanoparticles and Leaf‐Shaped Microstructure PTFE Film for Scavenging Mechanical Energy
Authors: Zhu Jianxiong , Zhu Yali , Wang Xiaohu 
Published: November 2017

AbstractIn this paper, a hybrid of piezoelectric polyvinylidene fluoride (PVDF)/polytetrafluoroethylene (PTFE) compound film and triboelectric leaf‐shaped microstructure film for mechanical energy harvesting is first reported. The nanoparticles compound film is designed with PVDF particles and leaf‐shaped PTFE. The triboelectric nanogenerator (TENG) is positioned at the upper side of the prototype and the piezoelectric nanogenerator (PENG) is placed at the lower side. It is found that the designed PENG could greatly enhance the harvested power by a coupling effect of PVDF nanoparticles and the compound PVDF/PTFE film than commercial film, and the leaf‐shaped PTFE film could benefit the electric output for the TENG. The average output power density of TENG and PENG can achieve 2.75 and 0.15 mW m−2 with resistor 300 MΩ, respectively. It is found that with the increasing external accelerations on prototype, the maximum generated output voltage by this mechanic‐electric conversion could obtain around 55 and −5.6 V by the two peak values, respectively. In the end, a random test using finger tap to light eight light‐emitting diodes is demonstrated the mechanical energy conversion performance of the TENG and PENG with the generated peak voltage of TENG and PENG 25 and −5.2 V, respectively.
Effect of UV Irradiation and Heat Treatment on the Surface Potential Distribution of Monolayer WS2 on SiO2/Si and Au Substrates
Authors: Han Weipeng , Qi Junjie , Li Feng , Xu Minxuan , Bai Fan , Fang Youyin , Liu Xinxin , Zhang Yue 
Published: November 2017

AbstractThe surface potential is relevant to work function and Fermi level of materials, which is of great significance to the research of charge transport, carrier concentration, and nanodevices design. Here the effect of UV illumination and heat treatment on the surface potential distribution of chemical vapor deposition grown monolayer WS2 on SiO2/Si and Au substrates is studied statistically. The experimental observation indicates that with the increase in light intensity, the surface potential of WS2 decreases on SiO2/Si substrate, while increases on Au substrate. Heat treatment is introduced to tuning the surface potential of monolayer WS2, resulting in the surface potential of WS2 on SiO2/Si substrate decrease and increase on Au substrate after annealing, respectively. The mechanism of the observed phenomenon is discussed in terms of the surface modification of the adsorption/desorption of charges on surface, photoinduced carriers, and charge transfer. This study provides a significant insight into the surface properties and can help optimize the performance of electronic and photonic devices.
Hydrogenation of Carbonyl Derivatives Catalysed by Manganese Complexes Bearing Bidentate Pyridinyl‐Phosphine Ligands
Authors: Wei Duo , Bruneau‐Voisine Antoine , Chauvin Téo , Dorcet Vincent , Roisnel Thierry , Valyaev Dmitry A. , Lugan Noël , Sortais Jean‐Baptiste 
Published: November 2017

AbstractManganese(I) catalysts incorporating readily available bidentate 2‐aminopyridinyl‐phosphine ligands achieve a high efficiency in the hydrogenation of carbonyl compounds, significantly better than parent ones based on more elaborated and expensive tridentate 2,6‐(diaminopyridinyl)‐diphosphine ligands. The reaction proceeds with low catalyst loading (0.5 mol%) under mild conditions (50 °C) with yields up to 96%.magnified image
Ruthenium(II)‐Catalyzed C−H Chalcogenation of Anilides
Authors: Ma Wenbo , Weng Zhengyun , Rogge Torben , Gu Linghui , Lin Jiafu , Peng Ai , Luo Xiang , Gou Xiaojun , Ackermann Lutz 
Published: November 2017

AbstractRuthenium‐catalyzed C−H chalcogenations of anilides with readily available diselenides and disulfides have been achieved. Our strategy features ample substrate scope, affording the mono‐ortho selenylated and thiolated anilides with complete site selectivity control and high catalytic efficacy. Detailed mechanistic studies provide strong support for a facile base‐assisted internal electrophilic substitution (BIES) metalation event.magnified image
Ligand‐free Iron(II)‐Catalyzed N‐Alkylation of Hindered Secondary Arylamines with Non‐activated Secondary and Primary Alcohols via a Carbocationic Pathway
Authors: Nayal Onkar S. , Thakur Maheshwar S. , Kumar Manoranjan , Kumar Neeraj , Maurya Sushil K. 
Published: November 2017

AbstractSecondary benzylic alcohols represent a challenging class of substrates for N‐alkylation of amines. Herein, we describe an iron(II)‐catalyzed eco‐friendly protocol for N‐alkylation of secondary arylamines with secondary benzyl alcohols through a carbocationic pathway instead of the known borrowing hydrogen transfer (BHT) approach. Transiently generated carbocations, produced from alcohols via self‐condensation, were coupled with arylamines to provide highly functionalized amine products. The scope of this methodology involves N‐alkylation of primary, secondary and heterocyclic amines with primary/secondary benzylic, allylic and heterocyclic alcohols, which are common key structures in numerous pharmaceuticals drugs. The method can also be easily adopted for the amination of various natural products.magnified image
Chiral Phosphoric Acid Catalyzed Enantioselective Friedel‐Crafts Reaction of N‐Protected 4‐Aminoindoles with β,γ‐Unsaturated α‐Ketimino Esters
Authors: Ding Yu‐Yang , Xu Deng‐Feng , Meng Shan‐Shui , Li Yang , Zhao Jun‐Ling 
Published: November 2017

AbstractThrough a hydrogen bonding guided substrate modification strategy, we have developed a chiral phosphoric acid catalyzed highly enantioselective Friedel‐Crafts reaction of N‐protected 4‐aminoindoles with β,γ‐unsaturated α‐ketimino esters. The mechanism and origins of the enantioselectivity of this process are indentified using DFT calculations. Both the experimental and calculation results indicated that the NH moiety at the indole C4 position is essential for the stereocontrol of this reaction. To further examine the potential usefulness of this method, gram scale synthesis and derivatizations of one of the products were also carried out.magnified image