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Hierarchical palladium catalyst for highly active and stable water oxidation in acidic media

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National Science Review 2023年第2期10卷 157-164页

作者： Jing Peng Haofeng Sun Kun Ni Jiajing Wu Xinyu Sun Yueqi Su Han Cheng Yuhua Liu Yuqiao Guo Wentuan Bi yanwu zhu Changzheng Wu Yi Xie Hefei National Laboratory for Physical Science at the Microscale CAS Center for Excellence in NanoscienceiChEM (Collaborative Innovation Center of Chemistry for Energy Materials) and CAS Key Laboratory of Mechanical Behavior and Design of Materials University of Science and Technology of China Institute of Energy Hefei Comprehensive National Science Center

Acidic water electrolysis is of great importance for boosting the development of renewable energy.However,it severely suffers from the trade-off between high activity and long lifespan for oxygen evolution catalysts on the anode side.This is because the sluggish kinetics of oxygen evolution reaction necessitates the application of a high overpotential to achieve considerable current,which inevitably drives the catalysts far away from their thermodynamic equilibrium states.Here we demonstrate a new oxygen evolution model catalyst-hierarchical palladium(Pd) whose performance even surpasses the benchmark Ir-and Ru-based materials.The Pd catalyst displays an ultralow overpotential(196 mV),excellent durability and mitigated degradation(66 μV h-1) at 10 mA cm-2in 1 M HClO4.Tensile strain on Pd(111) facets weakens the binding of oxygen species on electrochemical etching-derived hierarchical Pd and thereby leads to two orders of magnitudes of enhancement of mass activity in comparison to the parent Pd bulk materials.Furthermore,the Pd catalyst displays the bifunctional catalytic properties for both oxygen and hydrogen evolutions and can deliver a current density of 2 A cm-2at a low cell voltage of 1.771 V when fabricated into polymer ele ctrolyte membrane ele ctrolyser.

关键词： palladium oxygen evolution reaction acidic condition strain electrolysis

Advances in in-situ characterizations of electrode materials for better supercapacitors

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Journal of Energy Chemistry 2021年第3期30卷 242-253页

作者： Xiaoli Su Jianglin Ye yanwu zhu Hefei National Research Center for Physical Sciences at the Microscale &Department of Materials Science and Engineering&CAS Key Laboratory of Materials for Energy ConversionIf i-ChEMUniversity of Science and Technology of ChinaHefei 230026AnhuiChina

In past decades,the performance of supercapacitors has been greatly improved by rationalizing the electrode materials at the nanoscale.However,there is still a lack of understanding on how the charges are efficiently stored in the electrodes or transported across the electrolyte/electrode interface.As it is very challenging to investigate the ion-involved physical and chemical processes with single experiment or computation,combining advanced analytic techniques with electrochemical measurements,i.e.,developing in-situ characterizations,have shown considerable prospect for the better understanding of behaviors of ions in electrodes for supercapacitors.Herein,we briefly review several typical in-situ techniques and the mechanisms these techniques reveal in charge storage mechanisms specifically in supercapacitors.Possible strategies for designing better electrode materials are also discussed.

关键词： Electric double layer capacitor Pseudocapacitor In-situ technique Charge storage mechanism

Mass production and industrial applications of graphene materials

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National Science Review 2018年第1期5卷 90-101页

作者： yanwu zhu Hengxing Ji Hui-Ming Cheng Rodney S.Ruoff Key Laboratory of Materials for Energy Conversion Chinese Academy of Sciences& Department of Materials Science and Engineering & iChEM (Collaborative Innovation Center of Chemistry for Energy Materials)University of Science and Technology of China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Tsinghua-Berkeley Shenzhen Institute (TBSI) Tsinghua University Center for Multidimensional Carbon Materials (CMCM) Institute for Basic Science (IBS) Department of Chemistry and School of Materials Science Ulsan National Institute of Science and Technology

Graphene is considered a promising material for industrial application based on the intensive laboratoryscale research in the fields of physics, chemistry, materials science and engineering, and biology over the last decade. Many companies have thus started to pursue graphene materials on a scale of tons(for the flake material) or hundreds of thousands of square meters(for the film material) for industrial applications. Though the graphene industry is still in its early stages, very significant progress in mass production and certain industrial applications has become obvious. In this report, we aim to give a brief review of the mass production of graphene materials for some industrial applications and summarize some features or challenges for graphene in the marketplace.

关键词： graphene materials mass production industrial application

A Sponge-Driven Elastic Interface for Lithium Metal Anodes

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Research 2019年第1期2019卷 541-550页

作者： Han Yu Jian Xie Na Shu Fei Pan Jianglin Ye Xinyuan Wang Hong Yuan yanwu zhu Hefei National Research Center for Physical Sciences at the Microscale and Department of Materials Science and Engineering and CAS Key Laboratory of Materials for Energy Conversion University of Science and Technology of ChinaHefeiAnhui 230026China iChEM(Collaborative Innovation Center of Chemistry for Energy Materials) University of Science and Technology of ChinaHefeiAnhui 230026China

The lithium(Li)metal is one promising anode for next generation high-energy-density batteries,but the large stress fluctuation and the nonuniform Li deposition upon cycling result in a highly unstable interface of the Li anode.Herein,a simple yet facile engineering of the elastic interface on the Li metal anodes is designed by inserting a melamine sponge between Li and the separator.Driven by the good elasticity of the sponge,the modified Li anode maintains a Coulombic efficiency of 98.8%for 60 cycles and is cyclable at 10 mA cm^(-2) for 250 cycles,both with a high capacity of 10 mA h cm^(-2).We demonstrate that the sponge can be used to replace the conventional polypropylene as a porous yet elastic separator,showing superior cycling and rate performance as well.In addition to the efficiency of the elastic interface on the cycling stability,which is further confirmed by an in situ compression-electrochemistry measurement,the porous structure and polar groups of the sponge demonstrate an ability of regulating the transport of Li ions,leading to a uniform deposition of Li and the suppression of Li dendrites in cycling.

关键词： sponge cycling Elastic

Cobalt and nitrogen atoms co-doped porous carbon for advanced electrical double-layer capacitors

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Chinese Chemical Letters 2021年第2期32卷 830-833页

作者： Aiqin Xiang Shuai Xie Fei Pan Hongchang Jin Yiheng Zhai yanwu zhu Xianghua Kong Hengxing Ji School of Chemistry and Chemical Engineering Hefei University of TechnologyHefei 230009China Hefei National Laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Materials for Energy Conversion.Department of Applied ChemistryUniversity of Science and Technology of China.Hefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Materials for Energy ConversionDepartment of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China CAS Key Laboratory of Materials for Energy Conversion Hefei 230026China

Electrical double-layer capacitors are widely concerned for their high power density,long cycling life and high cycling efficiency.However,their wide application is limited by their low energy density.In this study,we propose a simple yet environmental friendly method to synthesize cobalt and nitrogen atoms co-doped porous carbon(CoAT-NC) material.Cobalt atoms connected with primarily pyridinic nitrogen atoms can be uniformly dispersed in the amorphous carbon matrix,which is benefit for improving electrical conductivity and density of states of the carbon material.Therefore,an enhanced perfo rmance is expected when CoAT-NC is served as electrode in a supercapacitor device.CoAT-NC displays a good gravimetric capacitance of 160 F/g at 0.5 A/g combing with outstanding capacitance retention of 90% at an extremely high current density of 100 A/g in acid electrolyte.Furthermore,a good energy density of 30 Wh/kg can be obtained in the organic electrolyte.

关键词： Electrical double-layer capacitors Cobalt atoms Pyridinic nitrogen Co-doped Density of states

Synthesis of Isotopically-Labeled Graphite Films by Cold-Wall Chemical Vapor Deposition and Electronic Properties of Graphene Obtained from Such Films

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Nano Research 2009年第11期2卷 851-856页

作者： Weiwei Cai Richard D.Piner yanwu zhu Xuesong Li Zhenbing Tan Herman Carlo Floresca Changli Yang Li Lu M.J.Kim Rodney S.Ruoff Department of Mechanical Engineering and the Texas Materials Institute University of Texas at AustinAustinTX 78712USA Institute of Physics Chinese Academy of SciencesBeijing 100190China Department of Materials Science and Engineering University of Texas at DallasRichardsonTX 75083USA

We report the synthesis of isotopically-labeled graphite films on nickel substrates by using cold-wall chemical vapor deposition(CVD).During the synthesis,carbon from^(12)C-and^(13)C-methane was deposited on,and dissolved in,a nickel foil at high temperature,and a uniform graphite film was segregated from the nickel surface by cooling the sample to room temperature.Scanning and transmission electron microscopy,micro-Raman spectroscopy,and X-ray diffraction prove the presence of a graphite film.Monolayer graphene films obtained from such isotopically-labeled graphite films by mechanical methods have electron mobility values greater than 5000 cm^(2)·V^(-1)·s^(-1)at low temperatures.Furthermore,such films exhibit the half-integer quantum Hall effect over a wide temperature range from 2 K to 200 K,implying that the graphite grown by this cold-wall CVD approach has a quality as high as highly oriented pyrolytic graphite(HOPG).The results from transport measurements indicate that^(13)C-labeling does not significantly affect the electrical transport properties of graphene.

关键词： Chemical vapor deposition(CVD) isotopically-labeled graphite graphene

基于TC4/Ni杜瓦冷指焊缝微观组织及接头结构的研究

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红外技术 2024年第2期46卷 208-215页

作者：沈练李冉魏超群赵维艳朱鹏飞徐世春戚雁武昆明物理研究所云南昆明650223

针对微型节流制冷型红外焦平面探测器杜瓦冷指,选取TC4/Ni的钎焊形式,从钎焊方法和钎料类型的焊缝微观组织以及接头结构设计的可靠性等方面对TC4/Ni的钎焊工艺进行了研究。结果表明,结合应力、形变和降温时间仿真以及防锈蚀分析结果,研... 详细信息

针对微型节流制冷型红外焦平面探测器杜瓦冷指,选取TC4/Ni的钎焊形式,从钎焊方法和钎料类型的焊缝微观组织以及接头结构设计的可靠性等方面对TC4/Ni的钎焊工艺进行了研究。结果表明,结合应力、形变和降温时间仿真以及防锈蚀分析结果,研究TC4/Ni冷指端面结构钎焊工艺具有一定工程实用意义;并通过正交试验确定了高温真空钎焊+AgCu28钎料组合的较佳工艺方案,满足对控制元素偏析和减少焊接脆性相生成的目的;同时综合考虑钎透率、充耐压试验及剪切强度测试的结果,确定锥形焊缝为较佳焊接结构。

关键词：杜瓦冷指真空钎焊 TC4钛合金

猪源和犬源ELF4蛋白的亚细胞定位比较研究

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畜牧与兽医 2024年第3期56卷 45-53页

作者：高翠翠喻娇唐青海侯鑫军刘婷全飞杨刘建行赵婷芳赵铖朱钰英危艳武衡阳师范学院生命科学学院/南岳山区生物资源保护与利用湖南省重点实验室湖南衡阳421008 中国农业科学院哈尔滨兽医研究所/兽医生物技术国家重点实验室黑龙江哈尔滨150069

本研究旨在对比分析猪E74样因子4(sELF4)和犬E74样因子4(cELF4)的亚细胞定位,为深入开展二者功能研究提供依据。利用PCR截短扩增sELF4和cELF4,分别克隆至真核表达载体pEGFP-C1中,构建17个sELF4重组真核表达载体和13个cELF4重组真核表达... 详细信息

本研究旨在对比分析猪E74样因子4(sELF4)和犬E74样因子4(cELF4)的亚细胞定位,为深入开展二者功能研究提供依据。利用PCR截短扩增sELF4和cELF4,分别克隆至真核表达载体pEGFP-C1中,构建17个sELF4重组真核表达载体和13个cELF4重组真核表达质粒,转染HeLa细胞、Hoechst33342染色,荧光倒置显微镜观察亚细胞定位,运用生物信息学软件分析其编码氨基酸序列特征。结果表明,sELF4和cELF4蛋白全长均定位在细胞核中,sELF4 196~291 aa(586~873 bp)之间有可能存在两个细胞质核定位信号肽,cELF4的核定位信号肽分布在203~291 aa(607~873 bp),cELF4 292~663 aa(874~1 992 bp)、sELF4 292~662 aa(874~1 989 bp)在细胞中发生聚集现象。cELF4与sELF4氨基酸序列在第169~303位氨基酸之间均高度保守,其他区段均存在不同程度的差异。综上,sELF4蛋白全长和cELF4蛋白全长均定位在细胞核中,截短表达的羧基端功能区有聚集现象,二者的核定位信号肽分布有一定差异。

关键词：猪ELF4蛋白犬ELF4蛋白真核表达亚细胞定位

Effect of spectral resolution on the measurement of monoaromatic hydrocarbons by DOAS

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Journal of Environmental Sciences 2008年第5期20卷 632-640页

作者： PENG Fumin XIE Pinhua ZHANG Yinghua zhu yanwu SI Fuqi LIU Wenqing WANG Junde Key Laboratory of Environmental Optical and Technology Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 China College of Chemistry and Chemical Engineering Anhui University Hefei 230039 China Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

The excellent response characteristics and detection sensitivity with much lower operational cost and the capability to discriminate between the isomer of some monoaromatic hydrocarbons （MAHCs） make differential optical absorption spectroscopy （DOAS） a powerful tool to trace concentration variation of MAHCs. But due to the similarity in chemical structure, those MAHCs have the similar overlapped characteristic absorption structures, which make the selection of instrumental parameter critical to the accurate detection of MAHCs. Firstly, the spectral resolution used in DOAS system determines the nonlinear absorption of O2 and the mass dependence of characteristic absorption structure; thereby it determines the effect of elimination error of O2 absorption in the atmospheric spectra for the detection of MAHCs. Secondly, spectral resolution determines the differential absorption characteristics of twelve MAHCs representing major constituents in technical solvents used in the automobile industry and the interference of spectral overlapping. Thirdly, the spectral resolution determines the sensitivity, time resolution and linear range. So the spectral resolution range with the best ratio of signal to noise is used to determine the most suitable spectral resolution range, as well as the spectral resolution range that ensure the characteristic absorption structure of MAHCs and the minimization of O2 absorption interference. Finally, 0.15-0.16 nm （FWHM： full width at half maximum） is assumed to be closest to the optimum spectral resolution and it is confirmed by the results of practical measurement of MAHCs by DOAS.

关键词： differential optical absorption spectroscopy （DOAS） monoaromatic hydrocarbons （MAHCs） spectral resolution characteristic absorption structure