bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interface Design and Development of Coating Materials in Lithium–Sulfur Batteries
Authors: Li Xia , Sun Xueliang 
Published: May 2018

AbstractHigh‐energy Li‐S batteries have received extensive attention and are considered to be the most promising next‐generation electric energy storage devices beyond Li‐ion batteries. Interface design is an important direction to address challenges in the development of Li–S batteries. This review summarizes recently developed coatings and interlayer materials at various interfaces of Li–S batteries. In particular, advanced nanostructures and novel fabrication methods of coating and interlayer materials applied to Li–S batteries are highlighted. Furthermore, underlying mechanisms at the interfaces and electrochemical performance of the developed Li–S batteries are also discussed. Finally, existing challenges and the future development of interface design in high‐energy Li–S batteries are summarized and prospected.
Synthesis of Pt Hollow Nanodendrites with Enhanced Peroxidase‐Like Activity against Bacterial Infections: Implication for Wound Healing
Authors: Ge Cuicui , Wu Renfei , Chong Yu , Fang Ge , Jiang Xiumei , Pan Yue , Chen Chunying , Yin Jun‐Jie 
Published: May 2018

AbstractImproving the antibacterial activity of H2O2 and reducing its usage are requirements for wound disinfection. Nanomaterials with intrinsic peroxidase‐like properties are developed to enhance the antibacterial performance of H2O2 and avoid the toxicity seen with high H2O2 levels. Here, Pd–Pt core–frame nanodendrites consist of a dense array of platinum (Pt) branches on a Pd core are synthesized, and subsequently converted to Pt hollow nanodendrites by selective removal of the Pd cores by wet etching. The fabricated Pt hollow nanodendrites exert striking peroxidase‐like activity due to the maximized utilization efficiency of the Pt atoms and the presence of high‐index facets on their surfaces. By catalyzing the decomposition of H2O2 into more toxic hydroxyl radicals (•OH), Pt hollow nanodendrites exhibit excellent bactericidal activity against both Gram‐negative and Gram‐positive bacteria with the assistance of low concentrations of H2O2. Furthermore, Pt hollow nanodendrites accelerate wound healing in the presence of low doses of H2O2. In addition, no obvious adverse effects are observed at the given dose of nanodendrites. These findings can be used to guide the design of noble metal‐based nanomaterials as potential enzyme‐mimetic systems and advance the development of nanoenzymes to potentiate the antibacterial activity of H2O2.
Few Layered N, P Dual‐Doped Carbon‐Encapsulated Ultrafine MoP Nanocrystal/MoP Cluster Hybrids on Carbon Cloth: An Ultrahigh Active and Durable 3D Self‐Supported Integrated Electrode for Hydrogen Evolution Reaction in a Wide pH Range
Authors: Liu Baocang , Li Huan , Cao Bo , Jiang Jianing , Gao Rui , Zhang Jun 
Published: May 2018

AbstractDevelopment of highly active and stable electrocatalysts is a key to realize efficient hydrogen evolution through water electrolysis. Here, the development of a 3D self‐supported integrated electrode constituting few layered N, P dual‐doped carbon‐encapsulated ultrafine MoP nanocrystal/MoP cluster hybrids on carbon cloth (FLNPC@MoP‐NC/MoP‐C/CC) is demonstrated. Benefiting from novel structural features including fully open and accessible nanoporosity, ultrasmall size of MoP‐NCs on MoP‐Cs as well as strong synergistic effects of N, P dual‐doped carbon layers with MoP‐NCs, the FLNPC@MoP‐NC/MoP‐C/CC as a 3D self‐supported binder‐free integrated electrode exhibits extraordinary catalytic activity for the hydrogen evolution reaction (HER) with extremely low overpotentials at all pH values ( j = 10 mA cm−2 at η = 74, 106, and 69 mV in 0.5 m H2SO4, 1.0 m PBS, and 1.0 m KOH electrolytes, respectively). To the best of our knowledge, the ultrahigh electrocatalytic performance represents one of the best MoP‐based HER electrocatalysts reported so far. Additionally, few layered N, P dual‐doped carbon can effectively prevent MoP‐NC/MoP‐C from corrosion, making the FLNPC@MoP‐NC/MoP‐C/CC exhibit nearly unfading stability after 50 h testing in acidic, neutral, and alkaline media, which shows great promise for electrocatalytic water splitting application.
Efficient and Ambient‐Air‐Stable Solar Cell with Highly Oriented 2D@3D Perovskites
Authors: Ye Tao , Bruno Annalisa , Han Guifang , Koh Teck Ming , Li Jia , Jamaludin Nur Fadilah , Soci Cesare , Mhaisalkar Subodh G. , Leong Wei Lin 
Published: May 2018

Abstract3D organic–inorganic lead halide perovskites have shown great potential in efficient photovoltaic devices. However, the low stability of the 3D perovskite layer and random arrangement of the perovskite crystals hinder its commercialization road. Herein, a highly oriented 2D@3D ((AVA)2PbI4@MAPbI3) perovskite structure combining the advantages of both 2D and 3D perovskite is fabricated through an in situ route. The highest power conversion efficiency (PCE) of 18.0% is observed from a 2D@3D perovskite solar cell (PSC), and it also shows significantly enhanced device stability under both inert (90% of initial PCE for 32 d) and ambient conditions (72% of initial PCE for 20 d) without encapsulation. The high efficiency of 18.0% and nearly twofold improvement of device stability in ambient compared with pure 3D PSCs confirm that such 2D@3D perovskite structure is an effective strategy for high performance and increasing stability and thus will enable the timely commercialization of PSCs.
Ferroelectric Sr3Zr2O7: Competition between Hybrid Improper Ferroelectric and Antiferroelectric Mechanisms
Authors: Yoshida Suguru , Fujita Koji , Akamatsu Hirofumi , Hernandez Olivier , Sen Gupta Arnab , Brown Forrest G. , Padmanabhan Haricharan , Gibbs Alexandra S. , Kuge Toshihiro , Tsuji Ryosuke , Murai Shunsuke , Rondinelli James M. , Gopalan Venkatraman , Tanaka Katsuhisa 
Published: May 2018

AbstractIn contrast to polar cation displacements driving oxides into noncentrosymmetric and ferroelectric states, inversion‐preserving anion displacements, such as rotations or tilts of oxygen octahedra about cation coordination centers, are exceedingly common. More than one nonpolar rotational mode in layered perovskites can lift inversion symmetry and combine to induce an electric polarization through a hybrid improper ferroelectric (HIF) mechanism. This form of ferroelectricity expands the compositional palette to new ferroelectric oxides because its activity derives from geometric rather than electronic origins. Here, the new Ruddlesden–Popper HIF Sr3Zr2O7, which is the first ternary lead‐free zirconate ferroelectric, is reported and room‐temperature polarization switching is demonstrated. This compound undergoes a first‐order ferroelectric‐to‐paraelectric transition, involving an unusual change in the “sense” of octahedral rotation while the octahedral tilt remains unchanged. Our experimental and first‐principles study shows that the paraelectric polymorph competes with the polar phase and emerges from a trilinear coupling of rotation and tilt modes interacting with an antipolar mode. This form of hybrid improper “antiferroelectricity” is recently predicted theoretically but has remained undetected. This work establishes the importance of understanding anharmonic interactions among lattice degrees of freedom, which is important for the discovery of new ferroelectrics and likely to influence the design of next‐generation thermoelectrics.
Approaching the Downsizing Limit of Maricite NaFePO4 toward High‐Performance Cathode for Sodium‐Ion Batteries
Authors: Liu Yongchang , Zhang Ning , Wang Fanfan , Liu Xiaobin , Jiao Lifang , Fan Li‐Zhen 
Published: May 2018

AbstractMaricite NaFePO4 nanodots with minimized sizes (≈1.6 nm) uniformly embedded in porous N‐doped carbon nanofibers (designated as NaFePO4@C) are first prepared by electrospinning for maximized Na‐storage performance. The obtained flexible NaFePO4@C fiber membrane adherent on aluminum foil is directly used as binder‐free cathode for sodium‐ion batteries, revealing that the ultrasmall nanosize effect as well as a high‐potential desodiation process can transform the generally perceived electrochemically inactive maricite NaFePO4 into a highly active amorphous phase; meanwhile, remarkable electrochemical performance in terms of high reversible capacity (145 mA h g−1 at 0.2 C), high rate capability (61 mA h g−1 at 50 C), and unprecedentedly high cyclic stability (≈89% capacity retention over 6300 cycles) is achieved. Furthermore, the soft package Na‐ion full battery constructed by the NaFePO4@C nanofibers cathode and the pure carbon nanofibers anode displays a promising energy density of 168.1 Wh kg−1 and a notable capacity retention of 87% after 200 cycles. The distinctive 3D network structure of very fine NaFePO4 nanoparticles homogeneously encapsulated in interconnected porous N‐doped carbon nanofibers, can effectively improve the active materials' utilization rate, facilitate the electrons/Na+ ions transport, and strengthen the electrode stability upon prolonged cycling, leading to the fascinating Na‐storage performance.
Highly Brilliant Noniridescent Structural Colors Enabled by Graphene Nanosheets Containing Graphene Quantum Dots
Authors: Zhang Yingxue , Han Peng , Zhou Haiyan , Wu Na , Wei Yu , Yao Xi , Zhou Jinming , Song Yanlin 
Published: May 2018

AbstractThe most important properties of noniridescent structural colors of amorphous photonic structures (APS) are sufficient color brightness and saturation, which are difficult to be optimized simultaneously. Herein, highly saturated and brilliant noniridescent structural colors are achieved by introducing graphene nanosheets, which contain a fraction of graphene quantum dots (GQDs), into the short‐range ordered APS. The effective modulation of the photoluminescence (PL) of GQDs by the selective enhancement of absorption at the blue pseudo photonic bandgap edges of the APS boosts the PL with wavelength matching that of the photonic bandgap and thus enables high structural color brightness; the uniform light absorption of graphene nanosheets in the whole visible spectra contributes to the high color saturation. Furthermore, by using APS films with short‐range order as templates, a brilliant colorful humidity sensor is demonstrated. Compared with the conventional sensing platform based on photonic crystals, the humidity sensor with brilliant noniridescent structural colors is more convenient by avoiding the confusing color dependence on the viewing angles. The improvement in the structural color brightness of the APS films by facile graphene doping will facilitate their practical applications in fields of decorations, packaging, pigments, sensors, displays, or other color‐related areas.
A Nanostructuring Method to Decouple Electrical and Thermal Transport through the Formation of Electrically Triggered Conductive Nanofilaments
Authors: Durán Retamal José Ramón , Kang Chen‐Fang , Lien Der‐Hsien , Kuo Wei‐Cheng , Juang Zhen‐Yu , Tsai Meng‐Lin , Ho Chih‐Hsiang , Juang Jenh‐Yih , Hsiao Vincent K. S. , Chu Ying‐Hao , Li Lain‐Jong , Wu Yue , He Jr‐Hau 
Published: May 2018

AbstractTransforming thermal energy into electric energy and vice versa needs the decoupling of electrical transport from thermal transport. An innovative strategy is proposed by forming/disrupting electrically triggered conductive nanofilaments within semiconducting thin films to switch thermoelectric properties between two states without further material modification and manufacturing processes. It can also controllably adjust the degree of decoupling, providing a potential resolution and performance adjustability for heat/coldness control or power consumption reduction on demand.
Untethered Recyclable Tubular Actuators with Versatile Locomotion for Soft Continuum Robots
Authors: Qian Xiaojie , Chen Qiaomei , Yang Yang , Xu Yanshuang , Li Zhen , Wang Zhenhua , Wu Yahe , Wei Yen , Ji Yan 
Published: May 2018

AbstractStimuli‐responsive materials offer a distinguished platform to build tether‐free compact soft robots, which can combine sensing and actuation without a linked power supply. In the past, tubular soft robots have to be made by multiple components with various internal channels or complex cavities assembled together. Moreover, robust processing, complex locomotion, simple structure, and easy recyclability represent major challenges in this area. Here, it is shown that those challenges can be tackled by liquid crystalline elastomers with allyl sulfide functional groups. The light‐controlled exchange reaction between allyl sulfide groups allows flexible processing of tubular soft robots/actuators, which does not need any assisting materials. Complex locomotion demonstrated here includes reversible simultaneous bending and elongation; reversible diameter expansion; and omnidirectional bending via remote infrared light control. Different modes of actuation can be programmed into the same tube without the routine assembly of multiple tubes as used in the past. In addition, the exchange reaction also makes it possible to use the same single tube repeatedly to perform different functions by erasing and reprogramming.
Alginate‐Derived Salt/Polymer Composites for Thermochemical Heat Storage
Authors: Kallenberger Paul A. , Posern Konrad , Linnow Kirsten , Brieler Felix J. , Steiger Michael , Fröba Michael 
Published: May 2018

AbstractThermochemical heat storage composites based on inorganic salt hydrates embedded in a hydrogel‐derived polymeric matrix are presented. The synthesis offers the flexibility to obtain composites with different incorporated salts such as MgSO4, MgCl2, CaCl2, and SrCl2. The incorporated salts can release and store heat through reversible hydration and dehydration while the use of an alginate‐based matrix allows macroscopic structuring of the composite as beads that provide little pressure loss in packed beds. The synthesis is simple, can be scaled up and carried out in continuous flow. Charging temperatures below 150 °C, high volumetric storage densities of up to 1.50 kJ cm−3 (417 kWh m−3) combined with a macroscopic shape that allows easy vapor diffusion through packed beds present a major advance for heat storage materials based on salt hydrates.
Star‐Shaped Boron‐Containing Asymmetric Host Materials for Solution‐Processable Phosphorescent Organic Light‐Emitting Diodes
Authors: Jin Jibiao , Tao Ye , Jiang He , Chen Runfeng , Xie Guohua , Xue Qin , Tao Chen , Jin Lu , Zheng Chao , Huang Wei 
Published: May 2018

AbstractBoron‐containing compounds have attracted considerable attention because of their electron‐accepting properties, and they are widely used in a variety of fields. However, due to the essential requirement to protect the empty pz‐orbital of the boron atom using large steric hindrance or rigid groups, borane derivatives generally show poor solubility and are rarely reported as acceptor units to construct bipolar host materials for phosphorescent organic light‐emitting diodes (PhOLEDs). Here, a combined star‐shaped and asymmetric donor–acceptor molecular design strategy to improve the solubility and fine tune the optical and electronic properties of boron‐containing materials is presented. High thermal stability, solvent solubility, solution processability, and triplet energy are achieved simultaneously. With the thus‐designed boron‐containing bipolar molecules as host materials, the solution‐processed PhOLEDs exhibit high device performances, which are comparable to the vacuum‐processed counterparts, showing high external quantum efficiencies up to 18.5% and 14.5% in blue and white PhOLEDs, respectively. These results demonstrate the great potential of the star‐shaped and symmetry‐breaking borane derivatives in solution‐processable organic optoelectronic devices.
Surface‐Plasmon‐Assisted Photoelectrochemical Reduction of CO2 and NO3− on Nanostructured Silver Electrodes
Authors: Kim Youngsang , Creel Erin B. , Corson Elizabeth R. , McCloskey Bryan D. , Urban Jeffrey J. , Kostecki Robert 
Published: May 2018

AbstractElectrochemical reduction of carbon dioxide (CO2) typically suffers from low selectivity and poor reaction rates that necessitate high overpotentials, which impede its possible application for CO2 capture, sequestration, or carbon‐based fuel production. New strategies to address these issues include the utilization of photoexcited charge carriers to overcome activation barriers for reactions that produce desirable products. This study demonstrates surface‐plasmon‐enhanced photoelectrochemical reduction of CO2 and nitrate (NO3−) on silver nanostructured electrodes. The observed photocurrent likely originates from a resonant charge transfer between the photogenerated plasmonic hot electrons and the lowest unoccupied molecular orbital (MO) acceptor energy levels of adsorbed CO2, NO3−, or their reductive intermediates. The observed differences in the resonant effects at the Ag electrode with respect to electrode potential and photon energy for CO2 versus NO3− reduction suggest that plasmonic hot‐carriers interact selectively with specific MO acceptor energy levels of adsorbed surface species such as CO2, NO3−, or their reductive intermediates. This unique plasmon‐assisted charge generation and transfer mechanism can be used to increase yield, efficiency, and selectivity of various photoelectrochemical processes.
Ternary Organic Solar Cells With 12.8% Efficiency Using Two Nonfullerene Acceptors With Complementary Absorptions
Authors: Kan Bin , Yi Yuan‐Qiu‐Qiang , Wan Xiangjian , Feng Huanran , Ke Xin , Wang Yanbo , Li Chenxi , Chen Yongsheng 
Published: May 2018

AbstractA new small‐molecule acceptor (2,9‐bis(2‐methylene‐(3(1,1‐dicyanomethylene)benz[f]indanone))7,12‐dihydro‐(4,4,10,10‐tetrakis(4‐hexylphenyl)‐5,11‐diocthylthieno[3′,2′:4,5]cyclopenta[1,2‐b]thieno[2″,3″:3′,4′]cyclopenta[1′,2′:4,5]thieno[2,3‐f][1]benzothiophene) (NNBDT) based on naphthyl‐fused indanone ending units is reported. This molecule shows a narrow optical bandgap of 1.43 eV and effective absorption in the range of 700–870 nm. The devices based on poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithiophene))‐alt‐(5,5‐(1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethylhexyl)benzo[1′,2′‐c:4′,5′‐c′]dithiophene‐4,8‐dione))] (PBDB‐T):NNBDT yield a power conversion efficiency of 11.7% with a low energy loss of 0.55 eV and a high fill factor (FF) of 71.7%. Another acceptor (2,9‐bis(2‐methylene‐(3(1,1‐dicyanomethylene)benz[f]indanone))7,12‐dihydro‐4,4,7,7,12,12‐hexaoctyl‐4H‐cyclopenta[2″,1″:5,6;3″,4″:5′,6′]diindeno[1,2‐b:1′,2′‐b′]dithiophene (FDNCTF) is introduced as the third component to fabricate ternary devices. The two acceptors (NNBDT and FDNCTF) possess complementary absorption, same molecular orientation, and well‐miscible behavior. It is found that there exists a nonradiative energy transfer process from FDNCTF to NNBDT. The fullerene‐free ternary cells based on PBDB‐T:NNBDT:FDNCTF achieve a high efficiency of 12.8% with an improved short circuit current near 20 mA cm−2 in contrast to the binary devices. The result represents the best performance for fullerene‐free ternary solar cells reported to date and highlights the potential of ternary solar cells.
Schools as Vehicles to Assess Experiences, Improve Outcomes, and Effect Social Change
Authors: McMahon Susan Dvorak 
Published: May 2018

AbstractSchools are important settings that can be utilized to yield a positive impact on youth and the many issues our society faces. In this Presidential Address, I identify key issues and directions for the field, advocating that we need to expand our ecological focus, improve school climate, and collaborate with schools to effect change. To illustrate these key themes, findings from four projects with k‐12 youth and educators in the United States are described, and these projects have the following foci: protective factors for youth exposed to violence, teacher‐directed violence as part of an APA Task Force, school climate and neighborhood factors in relation to academic outcomes, and school transitions for students with disabilities. Challenges and future directions to build upon community psychology theory, research, practice, and policy are discussed.
Palladium(II)‐Catalyzed Enantioselective Arylation of Unbiased Methylene C(sp3)−H Bonds Enabled by a 2‐Pyridinylisopropyl Auxiliary and Chiral Phosphoric Acids
Authors: Yan Sheng‐Yi , Han Ye‐Qiang , Yao Qi‐Jun , Nie Xing‐Liang , Liu Lei , Shi Bing‐Feng 
Published: May 2018

AbstractEnantioselective functionalizations of unbiased methylene C(sp3)−H bonds of linear systems by metal insertion are intrinsically challenging and remain a largely unsolved problem. Herein, we report a palladium(II)‐catalyzed enantioselective arylation of unbiased methylene β‐C(sp3)−H bonds enabled by the combination of a strongly coordinating bidentate PIP auxiliary with a monodentate chiral phosphoric acid (CPA). The synergistic effect between the PIP auxiliary and the non‐C2‐symmetric CPA is crucial for effective stereocontrol. A broad range of aliphatic carboxylic acids and aryl bromides can be used, providing β‐arylated aliphatic carboxylic acid derivatives in high yields (up to 96 %) with good enantioselectivities (up to 95:5 e.r.). Notably, this reaction also represents the first palladium(II)‐catalyzed enantioselective C−H activation with less reactive and cost‐effective aryl bromides as the arylating reagents. Mechanistic studies suggest that a single CPA is involved in the stereodetermining C−H palladation step.
Formation of a Macrocycles‐in‐a‐Macrocycle Superstructure with All‐gauche Conformation by Reversible Radical Association
Authors: Yuan Liu , Han Yi , Tao Tao , Phan Hoa , Chi Chunyan 
Published: May 2018

AbstractThe formation of an unprecedented macrocycles‐in‐a‐macrocycle (MIM) superstructure by reversible radical–radical association of a triphenylamine based monomer terminated with three dicyanomethyl radicals is presented. The reaction yield is nearly quantitative and the obtained macrocycle contains three small dimeric macrocycles according to X‐ray crystallographic analysis. The six monomer molecules are linked by nine long dynamic covalent C(sp3)−C(sp3) bonds that all adopt a gauche conformation. Such a conformation favors the formation of a MIM structure rather than a 2D network with an all‐anti conformation. Two enantiomers with left‐/ right‐handed chirality exist in the single crystals of the superstructure.
Chromophore Activation of α,β‐Unsaturated Carbonyl Compounds and Its Application to Enantioselective Photochemical Reactions
Authors: Brenninger Christoph , Jolliffe John D. , Bach Thorsten 
Published: May 2018

AbstractThe first law of photochemistry, as described by Theodor von Grotthuß and John W. Draper, states that only the light absorbed by the irradiated matter can effect photochemical change. Consequently, the photochemical behavior of a molecule can be controlled by bringing its absorbance properties in line with the emission of the light source. A compound with a chromophore that only absorbs light at short wavelengths will not be excited by light of longer wavelengths. If one can reversibly modify the photophysical properties of a compound with a chemical activator, then it is possible to photoexcite only the activated species. For α,β‐unsaturated carbonyl compounds, the use of Lewis acids, Brønsted acids, or the formation of the respective iminium ions can bring about the desired chromophore activation to catalyze a photochemical reaction at a given wavelength. In this Minireview, the concept of chromophore activation will be illustrated, and examples of its implementation in enantioselective catalysis will be discussed.