作者机构：
[Xu, Yang; Xiao, Peng; Liao, Yanxia; Zhao, Jiong; Zhao, Yibo; Li, Zhuan; Tang, Huixian] Cent South Univ, Natl Key Lab Sci & Technol High strength Struct Ma, Changsha 410083, Peoples R China.;[Xu, Yang; Xiao, Peng; Liao, Yanxia; Zhao, Jiong; Zhao, Yibo; Li, Zhuan; Tang, Huixian] Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.;[Zou, Lingfeng] Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410114, Peoples R China.
通讯机构：
[Zhuan Li] N;National Key Laboratory of Science and Technology on High-strength Structural Materials, Central South University, Changsha, 410083, China<&wdkj&>State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, China
通讯机构：
[Chao, Zisheng; Fan, Jincheng] C;College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China. Electronic address:
摘要：
In this study, CoS/MnCo2O4-MnO2 (CMM) nanocomposites were synthesized by hydrothermal and then electrochemical deposition. Their electrochemical properties were systematically investigated for supercapacitors and energy-saving H-2 production. As an electrode material for supercapacitor, CMM demonstrates a specific capacitance of 2320F g(-1) at 1 A/g, and maintains a specific capacitance of 1216F g(-1) at 10 A/g. It also shows 72.8 % capacitance retention after 8000 cycles. The aqueous asymmetric supercapacitor exhibited high energy storage capacity (887.86F g(-1) specific capacitance at a current density of 1 A/g), good rate performance and cycling stability. Besides, CMM shows outstanding urea oxidation reaction(UOR) and glycol oxidation reaction (MOR) performances for H-2 production. Compared to oxygen evolution reaction (OER) (1.635 V) at 20 mA cm(-2), the potentials were reduced by 213 mV for UOR and 233 mV for MOR, respectively. Therefore, this study shows the promising practical applications of CMM nanocomposites for energy storage and energy-saving H-2 production. (C) 2022 Elsevier Inc. All rights reserved.
通讯机构：
[Zhaoyong Chen] C;College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha 410114, PR China<&wdkj&>Institute of New Energy and Power Battery, Changsha University of Science and Technology, Changsha 410114, PR China
摘要：
Voltage decay during cycling is the major problem for lithium-rich layered oxide cathodes. Here, we designed Sb-doped lithium-rich layered oxides prepared by a coprecipitation-solvent thermal method, aiming to alleviate the voltage decay of lithium-rich layered oxides. The midpoint discharge voltage and specific capacity of Li(1.20)Ni(0.133)Co(0.133)Mn(0.633)Sb(0.01)O(2) (LLMO-Sb1) demonstrate almost no decaying after 100 cycles at 1 C. Moreover, it exhibits a large rate capacity (215 mAh g(-1) at 5 C). The suppressed voltage decay and enhanced cycle performance of Sb-doped material are attributed to the high Sb-O bond energy, which can enhance the stability of the layered structure and suppress the layered-to-spinel phase transition. Moreover, Sb doping improves the rate capacity by reducing the energy barrier of lithium ion diffusion. This work opens a gate to prevent the oxidation of superoxo and peroxo, stabilizing the layered structure by selecting an element with a suitable radius and electronegativity.
通讯机构：
[Yong Han] S;[Xiaochun Liu] I;State Key Laboratory of Powder Metallurgy, Central South University, No. 932 South Lushan Road, Changsha, Hunan, 410083, PR China<&wdkj&>Institute of Metals, College of Material Science and Engineering, Changsha University of Science & Technology, 960, 2nd Section, Wanjiali RD, Changsha, Hunan, 410004, PR China
关键词：
Additive manufacturing;Laser metal deposition;Medium entropy alloys;Tungsten-based composites;W–CoCrNi composite
通讯机构：
[Xiong Pu; Qijun Sun] B;Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P. R. China<&wdkj&>School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China<&wdkj&>Center on Nanoenergy Research, School of Physical Science and Technology, Guangxi University, Nanning 530004, P. R. China<&wdkj&>CUSTech Institute, Wenzhou 325024, Zhejiang, P. R. China<&wdkj&>Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P. R. China<&wdkj&>School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China<&wdkj&>Center on Nanoenergy Research, School of Physical Science and Technology, Guangxi University, Nanning 530004, P. R. China
关键词：
Zn microbattery;helical electrodes;on-chip;high energy density;micro-/nanofabrication
期刊：
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,2022年144(7):3039-3049 ISSN：0002-7863
通讯作者：
Liu, M;Maier, SA
作者机构：
[Duan, Yuxia; Li, HuangJingWei; Liu, Min; Li, Hongmei; Yang, Baopeng; Cai, Chao; Liu, Kang; Fu, Junwei] Cent South Univ, Sch Phys & Elect, Hunan Joint Int Res Ctr Carbon Dioxide Resource U, State Key Lab Powder Met, Changsha 410083, Peoples R China.;[Liu, Changxu; Maier, Stefan A.; Maier, SA; Cortes, Emiliano] Ludwig Maximilians Univ Munchen, Chair Hybrid Nanosyst, Nanoinst Munich, Fac Phys, D-80539 Munich, Germany.;[Ou, Pengfei; Huang, Jianan Erick] Univ Toronto, Dept Elect & Comp Engn, Toronto, ON M5S IA4, Canada.;[Alkayyali, Tartela] Univ Toronto, Dept Mech & Ind Engn, Toronto, ON M5S, Canada.;[Liu, Hui; Chai, Liyuan] Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.
通讯机构：
[Liu, M ] C;[Maier, SA ] L;Cent South Univ, Sch Phys & Elect, Hunan Joint Int Res Ctr Carbon Dioxide Resource U, State Key Lab Powder Met, Changsha 410083, Peoples R China.;Ludwig Maximilians Univ Munchen, Chair Hybrid Nanosyst, Nanoinst Munich, Fac Phys, D-80539 Munich, Germany.
摘要：
Electrochemical CO2 reduction is a promising way to mitigate CO2 emissions and close the anthropogenic carbon cycle. Among products from CO2RR, multicarbon chemicals, such as ethylene and ethanol with high energy density, are more valuable. However, the selectivity and reaction rate of C-2 production are unsatisfactory due to the sluggish thermodynamics and kinetics of C-C coupling. The electric field and thermal field have been studied and utilized to promote catalytic reactions, as they can regulate the thermodynamic and kinetic barriers of reactions. Either raising the potential or heating the electrolyte can enhance C-C coupling, but these come at the cost of increasing side reactions, such as the hydrogen evolution reaction. Here, we present a generic strategy to enhance the local electric field and temperature simultaneously and dramatically improve the electric-thermal synergy desired in electrocatalysis. A conformal coating of similar to 5 nm of polytetrafluoroethylene significantly improves the catalytic ability of copper nanoneedles (similar to 7-fold electric field and similar to 40 K temperature enhancement at the tips compared with bare copper nanoneedles experimentally), resulting in an improved C-2 Faradaic efficiency of over 86% at a partial current density of more than 250 mA cm(-2) and a record-high C-2 turnover frequency of 11.5 +/- 0.3 s(-1) Cu site(-1). Combined with its low cost and scalability, the electric-thermal strategy for a state-of-the-art catalyst not only offers new insight into improving activity and selectivity of value-added C-2 products as we demonstrated but also inspires advances in efficiency and/or selectivity of other valuable electro-/photocatalysis such as hydrogen evolution, nitrogen reduction, and hydrogen peroxide electrosynthesis.
摘要：
The isotropic pyrocarbon bulk materials were prepared by the fixed-bed chemical vapor deposition method, and the internal structure was composed of ribbon-like structure and spherical structure together. The friction behaviors of isotropic pyrocarbon at room temperature were studied by characterizing the microstructure and friction morphology. The frictional properties of isotropic pyrocarbon are greatly influenced by internal ribbon-like pyrocarbon. With a higher content of ribbon-like pyrocarbon, the material produces a moderately rough friction film, which improves the stability of the friction coefficient. Meanwhile, ribbon-like pyrocarbon increases the hardness of the material and reduces its wear rate. In addition, external stress can impact the friction behavior of the material. Increasing the external load causes the friction film to become more continuous and uniform, reducing the overall friction coefficient of the material. When the load is low (50 N and 100 N), the friction coefficient tends to stabilizemore quickly. Nevertheless, an excessive load (200 N) will result in the creation of grooves, making it difficult to stabilize the friction coefficient of the material. (c) 2022 The Authors. Published by Elsevier B.V.
通讯机构：
[Chang Liu; Hai Yang] S;[Guoqiang Zou] C;School of Chemistry and Chemical Engineering, Hunan Institute of Engineering, Xiangtan, China<&wdkj&>College of Chemistry and Chemical Engineering, Central South University, Changsha, China<&wdkj&>School of Chemistry and Chemical Engineering, Hunan Institute of Engineering, Xiangtan, China
作者机构：
[Bao, Chenguang; Yang, Li] College of Materials Science and Engineering, Hunan University, Changsha 410082, China;[Zeng, Qing] Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410114, China;Authors to whom correspondence should be addressed.;[Li, Fujin] College of Materials Science and Engineering, Changsha University of Science & Technology, Changsha 410114, China;[Wu, Wei; Shi, Lei] Hunan Zhongke Shinzoom Co., Ltd., Changsha 410118, China
通讯机构：
[Hongbo Liu; Yuxi Chen] C;College of Materials Science and Engineering, Hunan University, Changsha 410082, China<&wdkj&>Authors to whom correspondence should be addressed.
通讯机构：
[Qingsong Ma; Weiguo Mao] S;School of Materials Science and Engineering, Xiangtan University, Xiangtan, 411105, PR China<&wdkj&>College of Materials Science and Engineering, Changsha University of Science & Technology, Changsha, 410114, PR China<&wdkj&>Science and Technology on Advanced Ceramic Fibers &Composites Laboratory, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, 410073, PR China
关键词：
Precursor-derived ceramics;SiHfOC ceramics;Pyrolysis behavior;High temperature structural evolution
摘要：
Gradient nano-grained (GNG) structure has been developed to solve the notable dilemma of the strength-ductility. However, the surface plastic strain-induced grain refinement often results in cracking or peeling of materials when overloaded. This study proposed a bending compensated surface mechanical grinding treatment (BC-SMGT) for thin metallic sheets, where the elastic bending dynamically compensates the perpendicular indentation-induced penetration. This unique deformation feature results in gradient nanostructured layers, with a grain size ranging from similar to 80 nm to a few microns in a pure Cu sheet processed at both room temperature (RT) and cryogenic temperature (CT). A relatively thicker deformation layer and smaller top surface grain size in the CT Cu sample yields better strength-ductility synergy than that in the RT Cu sample, which benefits from the preserved nanograins. Our results advance the fundamental understanding of this newly developed deformation technique and enlighten the future application of GNG structures in metallic sheets at industrial scale.
