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  • Insights into Interfacial Synergistic Catalysis over Ni@TiO2-x Catalyst toward Water-Gas Shift Reaction
    J. Am. Chem. Soc. (IF 14.357) Pub Date : 2018-07-17
    Ming Xu, Siyu Yao, Deming Rao, Yiming Niu, Ning Liu, Mi Peng, Peng Zhai, Yi Man, Li-Rong Zheng, BIN WANG, Bingsen Zhang, Ding Ma, Min Wei

    The mechanism on interfacial synergistic catalysis for supported metal catalysts has long been explored and investigated in several important heterogeneous catalytic processes (e.g., water-gas shift (WGS) reaction). The modulation of metal-support interactions imposes a substantial influence on activity and selectivity of catalytic reaction, as a result of the geometric/electronic structure of interfacial sites. Although great efforts have validated the key role of interfacial sites in WGS over metal catalysts supported on reducible oxides, direct evidence at the atomic level is lacking and the mechanism of interfacial synergistic catalysis is still ambiguous. Herein, Ni nanoparticles supported on TiO2-x (denoted as Ni@TiO2-x) was fabricated via a structure topotactic transformation of NiTi-layered double hydroxide (NiTi-LDHs) precursor, which showed excellent catalytic performance for WGS reaction. In situ microscopy was carried out to reveal the partial encapsulation structure of Ni@TiO2-x catalyst. A combination study including in situ and operando EXAFS, in situ DRIFTS spectra combined with TPSR measurements substantiates a new redox mechanism based on interfacial synergistic catalysis. Notably, interfacial Ni species (electron-enriched Niδ− site) participates in the dissociation of H2O molecule to generate H2, accompanied with the oxidation of Niδ−−Ov−Ti3+ (Ov: oxygen vacancy) to Niδ+−O−Ti4+ structure. DFT calculations further verify that the interfacial sites of Ni@TiO2-x catalyst serve as the optimal active site with the lowest activation energy barrier (0.35 eV) for water dissociation. This work provides a fundamental understanding on interfacial synergistic catalysis toward WGS reaction, which is constructive for the rational design and fabrication of high activity heterogeneous catalysts.

    更新日期:2018-07-18
  • Disilanylene-bridged BODIPY-based D-σ-A architectures: a novel promising series of NLO chromophores
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-18
    Xianghui Zheng, Wei Du, Lizhi Gai, Xu-Qiong Xiao, Zhifang Li, Li-Wen Xu, Yupeng Tian, Mitsuo Kira, Hua Lu

    The synthesis and optical properties of a novel series of disilanylene-bridged BODIPY-based D-σ-A chromophores are reported. Si−Si σ-electrons are useful and impressible for tunable optical properties. The electron-donating group facilitates enhancement of the CT nature of the excited state through σ(Si-Si) orbital, leading to the remarkable two-photon absorption cross-sections.

    更新日期:2018-07-18
  • Iridium complex-based probe for photoluminescence lifetime imaging of human carboxylesterase 2 in living cells
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-18
    Zihe Yan, Jinyu Wang, Yanxin Zhang, Sichun Zhang, Juan Qiao, Xinrong Zhang

    A novel photoluminescence lifetime probe (Ir-TB) has been developed for the detection and imaging of hCE2 in living cells. Large lifetime increase by around 300 ns after the enzymatic reaction makes it an ideal tool to distinguish the hCE2-hydrolyzed probes from those non-hydrolyzed ones by PLIM for the first time.

    更新日期:2018-07-18
  • Fluorinated interphases
    Nat. Nanotech. (IF 37.49) Pub Date : 2018-07-16
    Qiang Zhang

    Fluorinated interphases Fluorinated interphases, Published online: 16 July 2018; doi:10.1038/s41565-018-0187-y Fluorine-rich layers on both anode and cathode protect the electrodes and provide rechargeable lithium metal batteries with high energy density and intrinsic safety.

    更新日期:2018-07-18
  • Dissipative adaptation in driven self-assembly leading to self-dividing fibrils
    Nat. Nanotech. (IF 37.49) Pub Date : 2018-07-16
    Esra te Brinke, Joost Groen, Andreas Herrmann, Hans A. Heus, Germán Rivas, Evan Spruijt, Wilhelm T. S. Huck

    Out-of-equilibrium self-assembly of proteins such as actin and tubulin is a key regulatory process controlling cell shape, motion and division. The design of functional nanosystems based on dissipative self-assembly has proven to be remarkably difficult due to a complete lack of control over the spatial and temporal characteristics of the assembly process. Here, we show the dissipative self-assembly of FtsZ protein (a bacterial homologue of tubulin) within coacervate droplets. More specifically, we show how such barrier-free compartments govern the local availability of the energy-rich building block guanosine triphosphate, yielding highly dynamic fibrils. The increased flux of FtsZ monomers at the tips of the fibrils results in localized FtsZ assembly, elongation of the coacervate compartments, followed by division of the fibrils into two. We rationalize the directional growth and division of the fibrils using dissipative reaction–diffusion kinetics and capillary action of the filaments as main inputs. The principle presented here, in which open compartments are used to modulate the rates of dissipative self-assembly by restricting the absorption of energy from the environment, may provide a general route to dissipatively adapting nanosystems exhibiting life-like behaviour.

    更新日期:2018-07-18
  • A quantum-dot heat engine operating close to the thermodynamic efficiency limits
    Nat. Nanotech. (IF 37.49) Pub Date : 2018-07-16
    Martin Josefsson, Artis Svilans, Adam M. Burke, Eric A. Hoffmann, Sofia Fahlvik, Claes Thelander, Martin Leijnse, Heiner Linke

    Cyclical heat engines are a paradigm of classical thermodynamics, but are impractical for miniaturization because they rely on moving parts. A more recent concept is particle-exchange (PE) heat engines, which uses energy filtering to control a thermally driven particle flow between two heat reservoirs1,2. As they do not require moving parts and can be realized in solid-state materials, they are suitable for low-power applications and miniaturization. It was predicted that PE engines could reach the same thermodynamically ideal efficiency limits as those accessible to cyclical engines3,4,5,6, but this prediction has not been verified experimentally. Here, we demonstrate a PE heat engine based on a quantum dot (QD) embedded into a semiconductor nanowire. We directly measure the engine’s steady-state electric power output and combine it with the calculated electronic heat flow to determine the electronic efficiency η. We find that at the maximum power conditions, η is in agreement with the Curzon–Ahlborn efficiency6,7,8,9 and that the overall maximum η is in excess of 70% of the Carnot efficiency while maintaining a finite power output. Our results demonstrate that thermoelectric power conversion can, in principle, be achieved close to the thermodynamic limits, with direct relevance for future hot-carrier photovoltaics10, on-chip coolers or energy harvesters for quantum technologies.

    更新日期:2018-07-18
  • Non-flammable electrolyte enables Li-metal batteries with aggressive cathode chemistries
    Nat. Nanotech. (IF 37.49) Pub Date : 2018-07-16
    Xiulin Fan, Long Chen, Oleg Borodin, Xiao Ji, Ji Chen, Singyuk Hou, Tao Deng, Jing Zheng, Chongyin Yang, Sz-Chian Liou, Khalil Amine, Kang Xu, Chunsheng Wang

    Rechargeable Li-metal batteries using high-voltage cathodes can deliver the highest possible energy densities among all electrochemistries. However, the notorious reactivity of metallic lithium as well as the catalytic nature of high-voltage cathode materials largely prevents their practical application. Here, we report a non-flammable fluorinated electrolyte that supports the most aggressive and high-voltage cathodes in a Li-metal battery. Our battery shows high cycling stability, as evidenced by the efficiencies for Li-metal plating/stripping (99.2%) for a 5 V cathode LiCoPO4 (~99.81%) and a Ni-rich LiNi0.8Mn0.1Co0.1O2 cathode (~99.93%). At a loading of 2.0 mAh cm−2, our full cells retain ~93% of their original capacities after 1,000 cycles. Surface analyses and quantum chemistry calculations show that stabilization of these aggressive chemistries at extreme potentials is due to the formation of a several-nanometre-thick fluorinated interphase.

    更新日期:2018-07-18
  • Surface chemistry and buried interfaces in all-inorganic nanocrystalline solids
    Nat. Nanotech. (IF 37.49) Pub Date : 2018-07-16
    Emilio Scalise, Vishwas Srivastava, Eric Janke, Dmitri Talapin, Giulia Galli, Stefan Wippermann

    Semiconducting nanomaterials synthesized using wet chemical techniques play an important role in emerging optoelectronic and photonic technologies. Controlling the surface chemistry of the nano building blocks and their interfaces with ligands is one of the outstanding challenges for the rational design of these systems. We present an integrated theoretical and experimental approach to characterize, at the atomistic level, buried interfaces in solids of InAs nanoparticles capped with Sn2S64– ligands. These prototypical nanocomposites are known for their promising transport properties and unusual negative photoconductivity. We found that inorganic ligands dissociate on InAs to form a surface passivation layer. A nanocomposite with unique electronic and transport properties is formed, that exhibits type II heterojunctions favourable for exciton dissociation. We identified how the matrix density, sulfur content and specific defects may be designed to attain desirable electronic and transport properties, and we explain the origin of the measured negative photoconductivity of the nanocrystalline solids.

    更新日期:2018-07-18
  • High Purcell factor generation of indistinguishable on-chip single photons
    Nat. Nanotech. (IF 37.49) Pub Date : 2018-07-16
    Feng Liu, Alistair J. Brash, John O’Hara, Luis M. P. P. Martins, Catherine L. Phillips, Rikki J. Coles, Benjamin Royall, Edmund Clarke, Christopher Bentham, Nikola Prtljaga, Igor E. Itskevich, Luke R. Wilson, Maurice S. Skolnick, A. Mark Fox

    On-chip single-photon sources are key components for integrated photonic quantum technologies. Semiconductor quantum dots can exhibit near-ideal single-photon emission, but this can be significantly degraded in on-chip geometries owing to nearby etched surfaces. A long-proposed solution to improve the indistinguishablility is to use the Purcell effect to reduce the radiative lifetime. However, until now only modest Purcell enhancements have been observed. Here we use pulsed resonant excitation to eliminate slow relaxation paths, revealing a highly Purcell-shortened radiative lifetime (22.7 ps) in a waveguide-coupled quantum dot–photonic crystal cavity system. This leads to near-lifetime-limited single-photon emission that retains high indistinguishablility (93.9%) on a timescale in which 20 photons may be emitted. Nearly background-free pulsed resonance fluorescence is achieved under π-pulse excitation, enabling demonstration of an on-chip, on-demand single-photon source with very high potential repetition rates.

    更新日期:2018-07-18
  • The need for levering heat
    Nat. Nanotech. (IF 37.49) Pub Date : 2018-07-16
    Christian Van den Broeck

    The need for levering heat The need for levering heat, Published online: 16 July 2018; doi:10.1038/s41565-018-0210-3 A quantum dot device reaches close to optimal thermoelectric efficiency by working with electrons that lever heat.

    更新日期:2018-07-18
  • Large anomalous Hall current induced by topological nodal lines in a ferromagnetic van der Waals semimetal
    Nat. Mater. (IF 39.235) Pub Date : 2018-07-16
    Kyoo Kim, Junho Seo, Eunwoo Lee, K.-T. Ko, B. S. Kim, Bo Gyu Jang, Jong Mok Ok, Jinwon Lee, Youn Jung Jo, Woun Kang, Ji Hoon Shim, C. Kim, Han Woong Yeom, Byung Il Min, Bohm-Jung Yang, Jun Sung Kim

    Topological semimetals host electronic structures with several band-contact points or lines and are generally expected to exhibit strong topological responses. Up to now, most work has been limited to non-magnetic materials and the interplay between topology and magnetism in this class of quantum materials has been largely unexplored. Here we utilize theoretical calculations, magnetotransport and angle-resolved photoemission spectroscopy to propose Fe3GeTe2, a van der Waals material, as a candidate ferromagnetic (FM) nodal line semimetal. We find that the spin degree of freedom is fully quenched by the large FM polarization, but the line degeneracy is protected by crystalline symmetries that connect two orbitals in adjacent layers. This orbital-driven nodal line is tunable by spin orientation due to spin–orbit coupling and produces a large Berry curvature, which leads to a large anomalous Hall current, angle and factor. These results demonstrate that FM topological semimetals hold significant potential for spin- and orbital-dependent electronic functionalities.

    更新日期:2018-07-18
  • Structural evolution of titanium dioxide during reduction in high-pressure hydrogen
    Nat. Mater. (IF 39.235) Pub Date : 2018-07-16
    Sencer Selcuk, Xunhua Zhao, Annabella Selloni

    The excellent photocatalytic properties of titanium oxide (TiO2) under ultraviolet light have long motivated the search for doping strategies capable of extending its photoactivity to the visible part of the spectrum. One approach is high-pressure and high-temperature hydrogenation, which results in reduced ‘black TiO2’ nanoparticles with a crystalline core and a disordered shell that absorbs visible light. Here we elucidate the formation mechanism and structural features of black TiO2 using first-principles-validated reactive force field molecular dynamics simulations of anatase TiO2 surfaces and nanoparticles at high temperature and under high hydrogen pressures. Simulations reveal that surface oxygen vacancies created upon reaction of H2 with surface oxygen atoms diffuse towards the bulk material but encounter a high barrier for subsurface migration on {001} facets of the nanoparticles, which initiates surface disordering. Besides confirming that the hydrogenated amorphous shell has a key role in the photoactivity of black TiO2, our results provide insight into the properties of the disordered surface layers that are observed on regular anatase nanocrystals under photocatalytic water-splitting conditions.

    更新日期:2018-07-18
  • Design rules for minimizing voltage losses in high-efficiency organic solar cells
    Nat. Mater. (IF 39.235) Pub Date : 2018-07-16
    Deping Qian, Zilong Zheng, Huifeng Yao, Wolfgang Tress, Thomas R. Hopper, Shula Chen, Sunsun Li, Jing Liu, Shangshang Chen, Jiangbin Zhang, Xiao-Ke Liu, Bowei Gao, Liangqi Ouyang, Yingzhi Jin, Galia Pozina, Irina A. Buyanova, Weimin M. Chen, Olle Inganäs, Veaceslav Coropceanu, Jean-Luc Bredas, He Yan, Jianhui Hou, Fengling Zhang, Artem A. Bakulin, Feng Gao

    The open-circuit voltage of organic solar cells is usually lower than the values achieved in inorganic or perovskite photovoltaic devices with comparable bandgaps. Energy losses during charge separation at the donor–acceptor interface and non-radiative recombination are among the main causes of such voltage losses. Here we combine spectroscopic and quantum-chemistry approaches to identify key rules for minimizing voltage losses: (1) a low energy offset between donor and acceptor molecular states and (2) high photoluminescence yield of the low-gap material in the blend. Following these rules, we present a range of existing and new donor–acceptor systems that combine efficient photocurrent generation with electroluminescence yield up to 0.03%, leading to non-radiative voltage losses as small as 0.21 V. This study provides a rationale to explain and further improve the performance of recently demonstrated high-open-circuit-voltage organic solar cells.

    更新日期:2018-07-18
  • Surface distortion as a unifying concept and descriptor in oxygen reduction reaction electrocatalysis
    Nat. Mater. (IF 39.235) Pub Date : 2018-07-16
    Raphaël Chattot, Olivier Le Bacq, Vera Beermann, Stefanie Kühl, Juan Herranz, Sebastian Henning, Laura Kühn, Tristan Asset, Laure Guétaz, Gilles Renou, Jakub Drnec, Pierre Bordet, Alain Pasturel, Alexander Eychmüller, Thomas J. Schmidt, Peter Strasser, Laetitia Dubau, Frédéric Maillard

    Tuning the surface structure at the atomic level is of primary importance to simultaneously meet the electrocatalytic performance and stability criteria required for the development of low-temperature proton-exchange membrane fuel cells (PEMFCs). However, transposing the knowledge acquired on extended, model surfaces to practical nanomaterials remains highly challenging. Here, we propose ‘surface distortion’ as a novel structural descriptor, which is able to reconciliate and unify seemingly opposing notions and contradictory experimental observations in regards to the electrocatalytic oxygen reduction reaction (ORR) reactivity. Beyond its unifying character, we show that surface distortion is pivotal to rationalize the electrocatalytic properties of state-of-the-art of PtNi/C nanocatalysts with distinct atomic composition, size, shape and degree of surface defectiveness under a simulated PEMFC cathode environment. Our study brings fundamental and practical insights into the role of surface defects in electrocatalysis and highlights strategies to design more durable ORR nanocatalysts.

    更新日期:2018-07-18
  • Intermixing and periodic self-assembly of borophene line defects
    Nat. Mater. (IF 39.235) Pub Date : 2018-07-16
    Xiaolong Liu, Zhuhua Zhang, Luqing Wang, Boris I. Yakobson, Mark C. Hersam

    Two-dimensional (2D) boron (that is, borophene) was recently synthesized following theoretical predictions1,2,3,4,5. Its metallic nature and high in-plane anisotropy combine many of the desirable attributes of graphene6 and monolayer black phosphorus7. As a synthetic 2D material, its structural properties cannot be deduced from bulk boron, which implies that the intrinsic defects of borophene remain unexplored. Here we investigate borophene line defects at the atomic scale with ultrahigh vacuum (UHV) scanning tunnelling microscopy/spectroscopy (STM/STS) and density functional theory (DFT). Under suitable growth conditions, borophene phases that correspond to the v1/6 and v1/5 models are found to intermix and accommodate line defects in each other with structures that match the constituent units of the other phase. These line defects energetically favour spatially periodic self-assembly that gives rise to new borophene phases, which ultimately blurs the distinction between borophene crystals and defects. This phenomenon is unique to borophene as a result of its high in-plane anisotropy and energetically and structurally similar polymorphs. Low-temperature measurements further reveal subtle electronic features that are consistent with a charge density wave (CDW), which are modulated by line defects. This atomic-level understanding is likely to inform ongoing efforts to devise and realize applications based on borophene.

    更新日期:2018-07-18
  • Interaction of consumer preferences and climate policies in the global transition to low-carbon vehicles
    Nat. Energy (IF 46.859) Pub Date : 2018-07-16
    David L. McCollum, Charlie Wilson, Michela Bevione, Samuel Carrara, Oreane Y. Edelenbosch, Johannes Emmerling, Céline Guivarch, Panagiotis Karkatsoulis, Ilkka Keppo, Volker Krey, Zhenhong Lin, Eoin Ó Broin, Leonidas Paroussos, Hazel Pettifor, Kalai Ramea, Keywan Riahi, Fuminori Sano, Baltazar Solano Rodriguez, Detlef P. van Vuuren

    Burgeoning demands for mobility and private vehicle ownership undermine global efforts to reduce energy-related greenhouse gas emissions. Advanced vehicles powered by low-carbon sources of electricity or hydrogen offer an alternative to conventional fossil-fuelled technologies. Yet, despite ambitious pledges and investments by governments and automakers, it is by no means clear that these vehicles will ultimately reach mass-market consumers. Here, we develop state-of-the-art representations of consumer preferences in multiple global energy-economy models, specifically focusing on the non-financial preferences of individuals. We employ these enhanced model formulations to analyse the potential for a low-carbon vehicle revolution up to 2050. Our analysis shows that a diverse set of measures targeting vehicle buyers is necessary to drive widespread adoption of clean technologies. Carbon pricing alone is insufficient to bring low-carbon vehicles to the mass market, though it may have a supporting role in ensuring a decarbonized energy supply.

    更新日期:2018-07-18
  • Nucleation of dislocations and their dynamics in layered oxide cathode materials during battery charging
    Nat. Energy (IF 46.859) Pub Date : 2018-07-16
    A. Singer, M. Zhang, S. Hy, D. Cela, C. Fang, T. A. Wynn, B. Qiu, Y. Xia, Z. Liu, A. Ulvestad, N. Hua, J. Wingert, H. Liu, M. Sprung, A. V. Zozulya, E. Maxey, R. Harder, Y. S. Meng, O. G. Shpyrko

    Lithium-rich layered oxides (LRLO) are among the leading candidates for the next-generation cathode material for energy storage, delivering 50% excess capacity over commercially used compounds. Despite excellent prospects, voltage fade has prevented effective use of the excess capacity, and a major challenge has been a lack of understanding of the mechanisms underpinning the voltage fade. Here, using operando three-dimensional Bragg coherent diffractive imaging, we directly observe the nucleation of a mobile dislocation network in LRLO nanoparticles. The dislocations form more readily in LRLO as compared with a classical layered oxide, suggesting a link between the defects and voltage fade. We show microscopically how the formation of partial dislocations contributes to the voltage fade. The insights allow us to design and demonstrate an effective method to recover the original high-voltage functionality. Our findings reveal that the voltage fade in LRLO is reversible and call for new paradigms for improved design of oxygen-redox active materials.

    更新日期:2018-07-18
  • Suppression of atomic vacancies via incorporation of isovalent small ions to increase the stability of halide perovskite solar cells in ambient air
    Nat. Energy (IF 46.859) Pub Date : 2018-07-16
    Makhsud I. Saidaminov, Junghwan Kim, Ankit Jain, Rafael Quintero-Bermudez, Hairen Tan, Guankui Long, Furui Tan, Andrew Johnston, Yicheng Zhao, Oleksandr Voznyy, Edward H. Sargent

    The degradation of perovskite solar cells in the presence of trace water and oxygen poses a challenge for their commercial impact given the appreciable permeability of cost-effective encapsulants. Point defects were recently shown to be a major source of decomposition due to their high affinity for water and oxygen molecules. Here, we report that, in single-cation/halide perovskites, local lattice strain facilitates the formation of vacancies and that cation/halide mixing suppresses their formation via strain relaxation. We then show that judiciously selected dopants can maximize the formation energy of defects responsible for degradation. Cd-containing cells show an order of magnitude enhanced unencapsulated stability compared to state-of-art mixed perovskite solar cells, for both shelf storage and maximum power point operation in ambient air at a relative humidity of 50%. We conclude by testing the generalizability of the defect engineering concept, demonstrating both vacancy-formation suppressors (such as Zn) and promoters (such as Hg).

    更新日期:2018-07-18
  • More stable when relaxed
    Nat. Energy (IF 46.859) Pub Date : 2018-07-16
    Aaron T. Fafarman

    More stable when relaxed More stable when relaxed, Published online: 16 July 2018; doi:10.1038/s41560-018-0217-x Perovskite solar cells are noted for their high performance and ease of synthesis, but are still plagued by concerns over their stability. Researchers are now demonstrating why higher performance and increased stability go hand-in-hand — and how to continue improving both.

    更新日期:2018-07-18
  • Concerted nucleophilic aromatic substitutions
    Nat. Chem. (IF 26.201) Pub Date : 2018-07-16
    Eugene E. Kwan, Yuwen Zeng, Harrison A. Besser, Eric N. Jacobsen

    Nucleophilic aromatic substitution (SNAr) is one of the most widely applied reaction classes in pharmaceutical and chemical research, providing a broadly useful platform for the modification of aromatic ring scaffolds. The generally accepted mechanism for SNAr reactions involves a two-step addition–elimination sequence via a discrete, non-aromatic Meisenheimer complex. Here we use 12C/13C kinetic isotope effect (KIE) studies and computational analyses to provide evidence that prototypical SNAr reactions in fact proceed through concerted mechanisms. The KIE measurements were made possible by a new technique that leverages the high sensitivity of 19F as an NMR nucleus to quantitate the degree of isotopic fractionation. This sensitive technique permits the measurement of KIEs on 10 mg of natural abundance material in one overnight acquisition. As a result, it provides a practical tool for performing detailed mechanistic analyses of reactions that form or break C–F bonds.

    更新日期:2018-07-18
  • Dopant-induced electron localization drives CO2 reduction to C2 hydrocarbons
    Nat. Chem. (IF 26.201) Pub Date : 2018-07-16
    Yansong Zhou, Fanglin Che, Min Liu, Chengqin Zou, Zhiqin Liang, Phil De Luna, Haifeng Yuan, Jun Li, Zhiqiang Wang, Haipeng Xie, Hongmei Li, Peining Chen, Eva Bladt, Rafael Quintero-Bermudez, Tsun-Kong Sham, Sara Bals, Johan Hofkens, David Sinton, Gang Chen, Edward H. Sargent

    The electrochemical reduction of CO2 to multi-carbon products has attracted much attention because it provides an avenue to the synthesis of value-added carbon-based fuels and feedstocks using renewable electricity. Unfortunately, the efficiency of CO2 conversion to C2 products remains below that necessary for its implementation at scale. Modifying the local electronic structure of copper with positive valence sites has been predicted to boost conversion to C2 products. Here, we use boron to tune the ratio of Cuδ+ to Cu0 active sites and improve both stability and C2-product generation. Simulations show that the ability to tune the average oxidation state of copper enables control over CO adsorption and dimerization, and makes it possible to implement a preference for the electrosynthesis of C2 products. We report experimentally a C2 Faradaic efficiency of 79 ± 2% on boron-doped copper catalysts and further show that boron doping leads to catalysts that are stable for in excess of ~40 hours while electrochemically reducing CO2 to multi-carbon hydrocarbons.

    更新日期:2018-07-18
  • Accelerating proton-coupled electron transfer of metal hydrides in catalyst model reactions
    Nat. Chem. (IF 26.201) Pub Date : 2018-07-16
    Tianfei Liu, Meiyuan Guo, Andreas Orthaber, Reiner Lomoth, Marcus Lundberg, Sascha Ott, Leif Hammarström

    Metal hydrides are key intermediates in catalytic proton reduction and dihydrogen oxidation. There is currently much interest in appending proton relays near the metal centre to accelerate catalysis by proton-coupled electron transfer (PCET). However, the elementary PCET steps and the role of the proton relays are still poorly understood, and direct kinetic studies of these processes are scarce. Here, we report a series of tungsten hydride complexes as proxy catalysts, with covalently attached pyridyl groups as proton acceptors. The rate of their PCET reaction with external oxidants is increased by several orders of magnitude compared to that of the analogous systems with external pyridine on account of facilitated proton transfer. Moreover, the mechanism of the PCET reaction is altered by the appended bases. A unique feature is that the reaction can be tuned to follow three distinct PCET mechanisms—electron-first, proton-first or a concerted reaction—with very different sensitivities to oxidant and base strength. Such knowledge is crucial for rational improvements of solar fuel catalysts.

    更新日期:2018-07-18
  • Spontaneous power source in ambient air of a well-directionally reduced graphene oxide bulk
    Energy Environ. Sci. (IF 30.067) Pub Date : 2018-07-17
    Liangti Qu, Huhu Cheng, Yaxin Huang, Fei Zhao, Ce Yang, Panpan Zhang, Lan Jiang, Gaoquan Shi

    Spontaneous electric potential is essential and wildly exists in living cell membranes of organism, which would provide a novel power-supply system without external stimuli. However, the highly complex and delicate biological structures have restricted the huge electric energy in practical applications. Herein, we report the spontaneous electric generation of a functional groups-reconfigured graphene oxide membrane in the ambient atmosphere, which was prepared by a directionally-induced thermal reduction strategy. The as-prepared asymmetric porous graphene oxide membrane (a-GOM) with a size of only 4 mm2 can proactively generate a sustained electrical voltage of up to 450 mV in the air without need of external stimuli such as mechanical movement, light, heat, liquid water and so on. Of practical importance, it is easy to reach a high voltage of more than 10 V by the simple series stacking of a-GOM units, powering many commercial electronic components such as liquid crystal display (LCD) and light-emitting diodes (LED). In addition, flexible and foldable power generation devices of soft package is achievable on the basis of the assembly of a-GOM units.

    更新日期:2018-07-18
  • Carbon dioxide splitting using an electro-thermochemical hybrid looping strategy
    Energy Environ. Sci. (IF 30.067) Pub Date : 2018-07-09
    Wesley Luc, Matthew Jouny, Jonathan Rosen, Feng Jiao
    更新日期:2018-07-18
  • Concentrated Mixed Cation Acetate “Water-in-Salt” Solutions as Green and Low Cost High Voltage Electrolytes for Aqueous Batteries
    Energy Environ. Sci. (IF 30.067) Pub Date : 2018-07-16
    Maria R. R Lukatskaya, Jeremy Feldblyum, David G. Mackanic, Franziska Lissel, Dominik L. Michels, Yi Cui, Zhenan Bao

    Electrolyte solutions are a key component of energy storage devices that significantly impact capacity, safety, and cost. Recent developments in “water-in-salt” (WIS) aqueous electrolyte research have enabled the demonstration of aqueous Li-ion batteries that operate with capacities and cyclabilities comparable with those of commercial non-aqueous Li-ion batteries. Critically, the use of aqueous electrolyte mitigates safety risks associated with non-aqueous electrolytes. However, the high cost and potential toxicity of imide-based WIS electrolytes limit their practical deployment. In this report, we disclose the efficacy of inexpensive, non-toxic mixed cation electrolyte systems for Li-ion batteries that otherwise provide the same benefits as current WIS electrolytes: extended electrochemical stability window and compatibility with traditional intercalation Li-ion battery electrode materials. We take advantage of the high solubility of potassium acetate to achieve the WIS condition in a eutectic mixture of lithium and potassium acetate; with water-to-cation ratio as low as 1.3. Our work suggests an important direction for the practical realization of safe, low-cost, and high-performance Li-ion batteries.

    更新日期:2018-07-18
  • Combined solid-state NMR, FT-IR and computational studies on layered and porous materials
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-07-17
    Geo Paul, Chiara Bisio, Ilaria Braschi, Maurizio Cossi, Giorgio Gatti, Enrica Gianotti, Leonardo Marchese
    更新日期:2018-07-18
  • Black phosphorus quantum dots: synthesis, properties, functionalized modification and applications
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-07-17
    Rijun Gui, Hui Jin, Zonghua Wang, Jinghong Li
    更新日期:2018-07-18
  • Structure and reactivity/selectivity control by oriented-external electric fields
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-07-06
    Sason Shaik, Rajeev Ramanan, David Danovich, Debasish Mandal
    更新日期:2018-07-18
  • Harnessing electrostatic catalysis in single molecule, electrochemical and chemical systems: a rapidly growing experimental tool box
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-06-27
    Simone Ciampi, Nadim Darwish, Heather M. Aitken, Ismael Díez-Pérez, Michelle L. Coote
    更新日期:2018-07-18
  • Correction: Covalent layer-by-layer films: chemistry, design, and multidisciplinary applications
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-06-27
    Qi An, Tao Huang, Feng Shi

    Correction for ‘Covalent layer-by-layer films: chemistry, design, and multidisciplinary applications’ by Qi An et al., Chem. Soc. Rev., 2018, DOI: 10.1039/c7cs00406k.

    更新日期:2018-07-18
  • Correction: Achieving biopolymer synergy in systems chemistry
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-06-27
    Yushi Bai, Agata Chotera, Olga Taran, Chen Liang, Gonen Ashkenasy, David G. Lynn

    Correction for ‘Achieving biopolymer synergy in systems chemistry’ by Yushi Bai et al., Chem. Soc. Rev., 2018, DOI: 10.1039/c8cs00174j.

    更新日期:2018-07-18
  • Misconceptions in electronic energy transfer: bridging the gap between chemistry and physics
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-06-25
    Peter A. Tanner, Lei Zhou, Changkui Duan, Ka-Leung Wong
    更新日期:2018-07-18
  • The polyol process: a unique method for easy access to metal nanoparticles with tailored sizes, shapes and compositions
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-06-14
    F. Fiévet, S. Ammar-Merah, R. Brayner, F. Chau, M. Giraud, F. Mammeri, J. Peron, J.-Y. Piquemal, L. Sicard, G. Viau
    更新日期:2018-07-18
  • Pillararene-based self-assembled amphiphiles
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-06-05
    Huacheng Zhang, Zhaona Liu, Yanli Zhao
    更新日期:2018-07-18
  • Externally controlled atom transfer radical polymerization
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-06-05
    Xiangcheng Pan, Marco Fantin, Fang Yuan, Krzysztof Matyjaszewski
    更新日期:2018-07-18
  • Achieving biopolymer synergy in systems chemistry
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-05-31
    Yushi Bai, Agata Chotera, Olga Taran, Chen Liang, Gonen Ashkenasy, David G. Lynn
    更新日期:2018-07-18
  • 更新日期:2018-07-18
  • Nano-designed semiconductors for electro- and photoelectro-catalytic conversion of carbon dioxide
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-05-25
    Lei Zhang, Zhi-Jian Zhao, Tuo Wang, Jinlong Gong
    更新日期:2018-07-18
  • Toward Automated Enzymatic Synthesis of Oligosaccharides
    Chem. Rev. (IF 52.613) Pub Date : 2018-07-16
    Liuqing Wen, Garrett Edmunds, Christopher Gibbons, Jiabin Zhang, Madhusudhan Reddy Gadi, Hailiang Zhu, Junqiang Fang, Xianwei Liu, Yun Kong, Peng George Wang
    更新日期:2018-07-18
  • Solar light harvesting with multinary metal chalcogenide nanocrystals
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-05-25
    Oleksandr Stroyuk, Alexandra Raevskaya, Nikolai Gaponik
    更新日期:2018-07-18
  • Photoredox Catalysis for Building C–C Bonds from C(sp2)–H Bonds
    Chem. Rev. (IF 52.613) Pub Date : 2018-07-16
    Chang-Sheng Wang, Pierre H. Dixneuf, Jean-François Soulé
    更新日期:2018-07-18
  • Engineering enzyme microenvironments for enhanced biocatalysis
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-05-25
    Louis Lancaster, Walaa Abdallah, Scott Banta, Ian Wheeldon
    更新日期:2018-07-18
  • High-Oxidation-State 3d Metal (Ti–Cu) Complexes with N-Heterocyclic Carbene Ligation
    Chem. Rev. (IF 52.613) Pub Date : 2018-07-16
    Jun Cheng, Lijun Wang, Peng Wang, Liang Deng
    更新日期:2018-07-18
  • Chirality in rotaxanes and catenanes
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-05-24
    E. M. G. Jamieson, F. Modicom, S. M. Goldup
    更新日期:2018-07-18
  • 更新日期:2018-07-18
  • Field studies reveal functions of chemical mediators in plant interactions
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-05-17
    Meredith C. Schuman, Ian T. Baldwin
    更新日期:2018-07-18
  • Nanomaterial–microbe cross-talk: physicochemical principles and (patho)biological consequences
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-05-17
    D. Westmeier, A. Hahlbrock, C. Reinhardt, J. Fröhlich-Nowoisky, S. Wessler, C. Vallet, U. Pöschl, S. K. Knauer, R. H. Stauber
    更新日期:2018-07-18
  • Two-dimensional transition metal carbides and nitrides (MXenes) for biomedical applications
    Chem. Soc. Rev. (IF 40.182) Pub Date : 2018-04-18
    Kai Huang, Zhongjun Li, Jing Lin, Gang Han, Peng Huang
    更新日期:2018-07-18
  • Living with Oxygen
    Acc. Chem. Res. (IF 20.955) Pub Date : 2018-07-17
    Harry B. Gray, Jay R. Winkler
    更新日期:2018-07-18
  • The Fate of the Peroxyl Radical in Autoxidation: How Does Polymer Degradation Really Occur?
    Acc. Chem. Res. (IF 20.955) Pub Date : 2018-07-17
    Leesa M. Smith, Heather M. Aitken, Michelle L. Coote
    更新日期:2018-07-18
  • Mass Spectrometry-Based Chemical and Enzymatic Methods for Global Analysis of Protein Glycosylation
    Acc. Chem. Res. (IF 20.955) Pub Date : 2018-07-16
    Haopeng Xiao, Suttipong Suttapitugsakul, Fangxu Sun, Ronghu Wu
    更新日期:2018-07-18
  • Nonporous Adaptive Crystals of Pillararenes
    Acc. Chem. Res. (IF 20.955) Pub Date : 2018-07-16
    Kecheng Jie, Yujuan Zhou, Errui Li, Feihe Huang
    更新日期:2018-07-18
  • Bimetallic sulfide nanoparticles confined by dual-carbon nanostructures as anodes for lithium-/sodium-ion batteries
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-17
    Jinmeng Lv, Daxun Bai, Lan Yang, Ying Guo, Hong Yan, Sailong Xu

    Bimetallic sulfide ((Ni0.3Co0.7)9S8) nanoparticles confined by dual-carbon nanostructures are prepared by pyrolyzing a mixture of surfactant-intercalated layered double hydroxide and melamine, and deliver a highly reversible capacity and decent rate capability as anode nanomaterials for lithium- and sodium-ion batteries.

    更新日期:2018-07-18
  • Enantioselective Aliphatic C-H Bond Oxidation Catalyzed by Bioinspired Complexes
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-17
    Michela Milan, Massimo Bietti, Miquel Costas

    Enantioselective oxidation of aliphatic C-H bonds simultaneoulsy installs functionality and chirality into hydrocarbon units, converting in a single step readily available, rather inert and unexpensive hydrocarbons into precious building blocks for organic synthesis. The reaction remains an open problem eager for catalyst development. Metal complexes reproducing structural and reactivity aspects of oxygenases are emerging as unique homogeneous catalysts for this class of reactions. The current work reviews the current status of field, analyzing the difficulties of the reaction, discussing principles of catalyst design, and critically highlighting the limitations of the current state-of-the-art methodologies.

    更新日期:2018-07-18
  • Electronic modulation of carbon encapsulated NiSe composite through Fe doping for synergistic oxygen evolution
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-17
    Bo Xu, Zhiming Chen, Xiaodong Yang, Xiaomei Wang, Yucheng Huang, Cuncheng Li

    Fe-doped NiSe encapsulated in carbon is synthesized through a simple method using filter paper as sacrificial support and carbon source, exhibiting remarkable OER performance. The doping of Fe modulates the electron property of NiSe and shifts the d-band of surface Ni atom toward the Fermi level, together with the good conductivity and porous structure of the filter paper derived carbon greatly enhance the catalytic activity and stability.

    更新日期:2018-07-18
  • Stronger Host-guest Binding Does Not Necessarily Give Brighter Particles: A Case Study on a Polymeric AIEE-tunable and Size-tunable Suprasphere
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-17
    Linxian Xu, Rongrong Wang, Wei Cui, Lingyun Wang, Herbert Meier, Hao Tang, Derong Cao

    The supraspheres were prepared from a pillar[5]arene-based linear polymer (the host) and several multitopic guests. According to host-guest binding studies in the nanosystems, the optical and structural properties (fluorescence capability, density, and particle size) of the nanoparticles were correlated not with the host-guest binding affinities, but with the relative fluorescence quantum yield.

    更新日期:2018-07-18
  • Dynamic kinetic asymmetric transformations of β-halo-α-keto esters by N,N′-dioxide/Ni(II)-catalyzed carbonyl-ene reaction
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-17
    Wen Liu, Weidi Cao, Haipeng Hu, Lili Lin, Xiaoming Feng

    Dynamic kinetic asymmetric transformations of racemic β-halo-α-keto esters through carbonyl-ene reaction were realized by using a chiral N,N′-dioxide-nickel(II) complex, giving the corresponding β-halo-α-hydroxy esters containing two vicinal chiral tri- and tetrasubstituted carbon centers in good yields and dr with excellent ee values without the use of extra bases. Meanwhile, a proposed reaction mechanism was presented according to the configuration of the product.

    更新日期:2018-07-18
  • Blue Light-promoted Cross-Coupling of Aryldiazoacetates and Diazocarbonyl Compounds
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-17
    Tiebo Xiao, Mingjing Mei, Yuwei He, Lei Zhou

    A blue light-promoted cross-coupling of two distinct diazo compounds was described. The reaction produces E-configured trisubstituted alkenes in good yields in the absence of catalysts and additives. The reactive free carbene intermediates were generated by selective photolysis of one of two diazo compounds upon the irradiation of blue light.

    更新日期:2018-07-18
  • Single-molecule magnet behaviour in a dysprosium-triradical complex
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-17
    Zhao-Xin Xiao, Hao Miao, Dong Shao, Haiyan Wei, Yi-Quan Zhang, Xin-Yi Wang

    The first triradical bridged binuclear penta-spin single-molecule magnet, [Dy2(hfac)6(BTR)], based on a nitronyl nitroxide triradical was synthesized and characterized. Theoretical calculations revealed the Dy-radical antiferromagnetic coupling and radical-radical ferromagnetic coupling. The SMM behavior is found to originate from the exchange states, rather than the isolated Dy3+ center.

    更新日期:2018-07-18
  • Diastereoselective self-assembly of bisheptahelicene on Cu(111)
    Chem. Commun. (IF 6.29) Pub Date : 2018-07-17
    Anaïs Mairena, Manfred Parschau, Johannes Seibel, Martin Wienke, Daniel Rentsch, Andreas Terfort, Karl-Heinz Ernst

    Stereochemical effects during two-dimensional crystallization of bisheptahelicene diastereomers on a Cu(111) surface have been studied with scanning tunnelling microscopy. The (M,M)- and (P,P)-enantiomers crystallize into a monolayer racemate lattice, whereas the (M,P)-diasteromers aggregate into their own monolayer phase.

    更新日期:2018-07-18
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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