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Reducing the vacancies associated with ferroelectric polarization to promote photocatalytic overall water splitting

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Science China Chemistry 2024年第10期67卷 3258-3264页

作者： Haozhi Qi Yuyang Kang Jian-An Liu Lichang Yin Wenyu Zhang Shangyi Ma jianhang qiu Lingli Li Weijin Hu Lianzhou Wang Gang Liu Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Nanomaterials Centre School of Chemical Engineering and Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandSt LuciaBrisbane QLD 4072Australia

Ferroelectric materials hold great promise in photocatalytic water splitting because their built-in electric field induced by the depolarization field can fulfill the separation of photogenerated ***,a number of intrinsic charged vacancy defects are simultaneously generated to screen the depolarized field for stabilizing the crystal structure,always resulting in severe recombination of photogenerated carriers and thus poor overall water splitting ***,we proposed a strategy to promote the separation and transport of photogenerated carriers of ferroelectric photocatalysts by adjusting the ferroelectric polarization and altering the coordination environment of elements to reduce the defect ***,we prepared a series of Ta-doped PbTiO_(3)with low Pb(V_(Pb))and O(V_(O))vacancy concentrations by reducing the polarization intensity and strengthening the Pb–O *** Ta-doped PbTiO_(3)shows efficient charge separation and greatly enhanced photocatalytic overall water splitting activity with the assistance of *** work highlights the importance of regulating ferroelectric polarization and vacancy defect concentration by the doping strategy in charge separation for photocatalytic water splitting.

关键词： PbTiO_(3) ferroelectric polarization vacancy defect element doping photocatalytic overall water splitting

Extraordinary radiation tolerance of a Ni nanocrystal-decorated carbon nanotube network encapsulated in amorphous carbon

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Journal of Materials Science & Technology 2023年第24期155卷 253-261页

作者： Kan Cui Yang Zhao Zhi Yu Miaosen Yu Xiaoqi Li Xingwei Huang jianhang qiu Liangting Sun Hongwei Zhao Ning Gao Kaiping Tai Chang Liu Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Department of Materials Science and Engineering University of Science and Technology of China Shenyang 110016 China Institute of Frontier and Interdisciplinary Science and Key Laboratory of Particle Physics and Particle Irradiation (MOE) Shandong University Qingdao 266237 China Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China

Nanostructured materials with abundant defect sinks show good radiation tolerance due to their efficient absorption of irradiation-induced interstitials and ***,the poor thermal stability and limited size of such nanomaterials severely limit their practical ***,we report a novel flexible free-standing network-structured hybrid consisting of amorphous carbon encapsulated nickel nanocrystals anchored on a single-wall carbon nanotube scaffold with excellent radiation tolerance up to 5 dpa at 673 K and exceptional thermal stability up to 1073 *** nano-scale Ni-SWCNT network with abundant Ni-SWCNT interfaces and grain boundaries provides effective sinks and fast transportation channels for defects,which effectively absorb irradiation-induced defects and improved the irradiation ***,the formation of a low-energy Ni-C interface and surface thermal grooves significantly reduces the system free energy and increased thermal *** amorphous carbon layer produces an external compressive radial stress that inhibits Ni grain boundaries from migrating,which greatly improves the thermal stability of the hybrid by pinning GBs at grooves between grains and facilitates the annihilation of irradiation-induced defects at the *** work provides a new strategy to improve the thermal stability and radiation tolerance of nano-materials used in an irradiation environment.

关键词： Radiation tolerance Ni nanocrystals Carbon nanotube Thermal stability Flexible hybrid

液态金属镶嵌半导体颗粒光电极中金属/半导体3D界面电子结构调控促进光电化学分解水

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Science China Materials 2024年第6期67卷 1804-1811页

作者：陈祥涛甄超邱建航李娜贾楠刘岗 Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

光电极通常由半导体吸光层和导电集流体两部分组成,两者间的界面电子结构直接影响导电集流体从半导体光吸收层中收集光生电荷的效率,尤其对于具有3D界面结构的液态金属镶嵌半导体颗粒的光电极.为此,本工作通过改变金属组分改变液态金属... 详细信息

光电极通常由半导体吸光层和导电集流体两部分组成,两者间的界面电子结构直接影响导电集流体从半导体光吸收层中收集光生电荷的效率,尤其对于具有3D界面结构的液态金属镶嵌半导体颗粒的光电极.为此,本工作通过改变金属组分改变液态金属的功函数,从而调节导电集流体与半导体吸光材料间3D界面的电子能带排列和接触类型,促进光生电荷的跨界面转移与收集,提升光电极的光电化学分解水活性.系统研究半导体与液态金属的功函数匹配关系发现,将ZnO颗粒嵌入铟锡(IT)低温液态金属中,会形成欧姆接触;而将其嵌入铋铟锡(BIT)低温液态金属中,则会形成肖特基接触.由于欧姆接触不存在肖特基接触的界面能垒而有利于光生电荷的跨界面转移与收集,因此,与铟锡低温液态金属镶嵌ZnO颗粒的光电极(IT/ZnO)相比铋铟锡低温液态金属镶嵌ZnO颗粒的光电极(BIT/ZnO)具有更为优异的电荷收集和分离能力,其光电化学分解水光电流密度可达0.62 mA cm^(-2),相比BIT/ZnO光电极的光电流密度(0.52 mA cm^(-2))提升了约19%,且在已报道的代表性ZnO光电极中处于前列.而与之相比,WO3、TiO_(2)或Cu2O因分别与IT和BIT形成相同的欧姆或肖特基型接触,两种低温液态金属镶嵌的WO3、TiO_(2)或Cu2O光电极具有几乎相同的光电催化活性.本工作展示了通过选择具有不同功函数的液态金属来改变金属/半导体接触类型以增强低温液态金属镶嵌半导体光电极性能的潜力,为规模化构建高效光电极提供了新的策略.

关键词： metal-embraced photoelectrodes 3D interfaces Oh-mic contact water splitting

可回收型各向同性热解石墨导电基底促进光电化学水分解

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Science China Materials 2023年第12期66卷 4663-4668页

作者：徐伟甄超邱建航杜宇飞白朔成会明刘岗 Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

导电基底发挥着收集和传输光生电荷的关键作用,是光电化学(PEC)水分解用光电极不可或缺的重要组成部分,但构建高效光电极鲜受关注.本工作中,基于各向同性热解石墨(IPG)高电导率和高功函的特性,我们开发了各向同性热解石墨(IPG)作为一种... 详细信息

导电基底发挥着收集和传输光生电荷的关键作用,是光电化学(PEC)水分解用光电极不可或缺的重要组成部分,但构建高效光电极鲜受关注.本工作中,基于各向同性热解石墨(IPG)高电导率和高功函的特性,我们开发了各向同性热解石墨(IPG)作为一种导电基底来构建高性能光电极.相比于氟掺杂的二氧化锡(FTO)和金属箔片等广泛使用的导电基底,该光电极能与Cu_(2)O形成欧姆接触,因此所得IPG/Cu_(2)O光电阴极呈现出比FTO/Cu_(2)O光阴极高60%的光电流密度.IPG基底上经过高温氮化所得的Ta_(3)N5薄膜(IPG/Ta_(3)N_(5))可以获得与Ta箔负载的Ta_(3)N_(5)光阳极相媲美的PEC性能.此外,Ta箔由于在氮化过程中会出现严重氢脆问题而不能循环使用,而IPG基底则可以循环用于光电极的制备,且能生长出具有相同PEC性能的半导体薄膜.这项工作为通过碳基导电基底构建用于PEC水分解的高效光电极提供了一种有吸引力的可替代选择.

关键词： isotropic pyrolytic graphite photoelectrochemical recycleable ohmic contact conductive substrate

六氟钽酸氨拓扑转变制备低深能级缺陷Ta_(3)N_(5)光阳极实现超低偏压光电化学分解水

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Chinese Journal of Catalysis 2024年第6期61卷 144-153页

作者：徐伟甄超朱华泽姚婷婷邱建航梁艳白朔陈春林成会明刘岗中国科学院金属研究所沈阳材料科学国家实验室辽宁沈阳110016 中国科学技术大学材料科学与工程学院辽宁沈阳110016 中国科学院金属研究所师昌绪先进材料创新中心辽宁沈阳110016 中国科学院深圳先进技术研究院碳中和技术研究所广东深圳518055

Ta_(3)N_(5)是一种具有2.1 eV直接带隙的n型半导体,其带隙跨越水的氧化还原电位.此外,Ta_(3)N_(5)的理论太阳能制氢效率(STH)高达15.9%,超过商业化应用的效率门槛(10%),是一种理想的光电化学分解水制氢光阳极材料.采用Ta2O5作为前驱体,... 详细信息

Ta_(3)N_(5)是一种具有2.1 eV直接带隙的n型半导体,其带隙跨越水的氧化还原电位.此外,Ta_(3)N_(5)的理论太阳能制氢效率(STH)高达15.9%,超过商业化应用的效率门槛(10%),是一种理想的光电化学分解水制氢光阳极材料.采用Ta2O5作为前驱体,在氨气气氛下高温氮化制备Ta_(3)N_(5)是一个由表及里的非均相氮化过程,该过程会产生大量的低价钽和氮空位等本征深能级缺陷,导致费米能级钉扎效应的产生,从而使得光生电压显著降低和光电流起始电位较高.因此,开发能够进行体相均相氮化的前驱体,以抑制Ta_(3)N_(5)深能级缺陷的产生,具有重要意义.本文采用气相溶剂热法,在钽箔上制备了一种六氟钽酸氨((NH_(4))_(2)Ta_(2)O_(3)F_(6))化合物,并以其多面体锥阵列薄膜作为前驱体,通过可控的氮化过程将前驱体结构拓扑转变为低深能级缺陷含量的Ta_(3)N_(5)多孔阵列薄膜.在高温氮化过程中,(NH_(4))_(2)Ta_(2)O_(3)F_(6)会释放含氮、氢和氟的气体小分子并形成贯穿体相的多孔通道,有利于氨气及氮化过程中产生的其他小分子物质的渗透,促进体相均匀氮化过程,避免生成大量的本征深能级缺陷.同时,(NH_(4))_(2)Ta_(2)O_(3)F_(6)中的高电负性氟离子可以减弱Ta–O键,进一步促进氮化反应.扫描电镜和透射电镜(TEM)结果表明,制备的(NH_(4))_(2)Ta_(2)O_(3)F_(6)是具有实心结构的多面体锥阵列薄膜,而拓扑转变所得的Ta_(3)N_(5)多面体锥薄膜具有多孔结构.X射线光电子能谱(XPS)、紫外-可见漫反射光谱和稳态/瞬态光电压谱表征结果表明,通过(NH_(4))_(2)Ta_(2)O_(3)F_(6)拓扑转变制备Ta_(3)N_(5)可有效抑制Ta_(3)N_(5)薄膜中深能级缺陷的形成.采用两种产氧反应助催化剂依次修饰后,XPS和TEM结果显示出助催化剂的双壳层结构与化学组成.光电化学分解水测试结果表明,所制得的Ta_(3)N_(5)光阳极在AM1.5G模拟太阳光的照射下,可展现出0.2 V_(RHE)(***)的极低光电流起始电位,且在1.23 V_(RHE)时的光电流密度可达3.28 mA cm^(–2),经过连续5 h的稳定性测试,仍能保持初始值的85%.此外,稳定性测试前后助催化剂的XPS和TEM结果表明,Ta_(3)N_(5)光阳极光电流下降的原因可能是产氧助催化剂中硼物种的消耗.而通过减小(NH_(4))_(2)Ta_(2)O_(3)F_(6)多面体锥前驱体的尺寸,可以进一步减少Ta_(3)N_(5)薄膜中的本征深能级缺陷的含量,修饰助催化剂后可在0 V_(RHE)下展现出光电催化水氧化活性.综上所述,通过(NH_(4))_(2)Ta_(2)O_(3)F_(6)新型前驱体拓扑转变制备了低深能级缺陷含量的Ta_(3)N_(5)光阳极,表现出极低的光电流起始电位,为构建无偏压下自发全分解水的低深能级缺陷浓度的Ta_(3)N_(5)光电极提供了一种新途径,该方法也可拓展至其他过渡金属氮化物的可控制备与缺陷调控.

关键词： (NH_(4))_(2)Ta_(2)O_(3)F_(6) 拓扑转变低缺陷Ta3N5 起始电位光电化学分解水

Molecular verification of the integration of Tripsacum dactyloides DNA into wheat genome through wide hvbridization

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Chinese Science Bulletin 2000年第6期45卷 528-532页

作者： qiu Jiwen JIN Demin LI Chuanyou JIA jianhang OUYANG Ping William TAI WANG Bin LI Dawei State Key Laboratory of Plant Cell and Chromosome Engineering Institute of GeneticsChinese Academy of SciencesBeijing100101.China Plant Biotechnology Laboratory Institute of GeneticsChinese Academy of SciencesBeijing 100101China Institute for Global Chinese Affairs University of MarylandUSA

RAPD and RFLP analyses of double haploid lines which derived from hybridization between hexaploid wheat (Triticum aestivum L. 2n=42) and eastern gamagrass (Tripsacum dactyloides L. 2n=4x=72) are reported. Two of the 340 Operon primers have been screened, which stably amplified Tripsacum dactyloides (male parent) specific bands in the double haploid lines. These results confirm the fact that Tripsacum dactyloides DNA has been integrated into wheat genome by sexual hybridization at molecular level. This idea has been further testified by RFLP analysis. Application and potentials of transferring Tripsacum dactyloides DNA into wheat genome by sexual hybridization in wheat breeding are discussed.

关键词： bread wheat Tripsacum dactyloides wide hybridization RAPD RFLP.

Large-Area Monolayer n-Type Molecular Semiconductors with Improved Thermal Stability and Charge Injection

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Chinese Physics Letters 2023年第3期40卷 68-73页

作者： Sai Jiang Lichao Peng Xiaosong Du Qinyong Dai jianhang Guo Jianhui Gu Jian Su Ding Gu Qijing Wang Huafei Guo Jianhua qiu Yun Li School of Microelectronics and Control Engineering Changzhou UniversityChangzhou 213164China National Laboratory of Solid-State Microstructures School of Electronic Science and EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

We fabricated monolayer n-type two-dimensional crystalline semiconducting films with millimeter-sized areas and remarkable morphological uniformity using an antisolvent-confined spin-coating *** antisolvent can cause a downstream Marangoni flow,which improves the film *** deposited crystalline monolayer films exhibit excellent thermal stabilities after annealing,which reveals the annealing-induced enhancement of *** transistors based on the n-type monolayer crystalline films show linear output characteristics and superior electron *** improved charge injection between monolayer films and Au electrodes results from the energy level shift as the films decrease to the monolayer,which leads to a lower injection *** work demonstrates a promising method for fabricating air-stable,low-cost,high-performance,and large-area organic electronics.

关键词： monolayer crystalline annealing

The Design and Service Life's Research of Formula Student Racecar Wheel System Structure Based on Spline Connection

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The Design and Service Life's Research of Formula Student Ra...

淬硬超高强度钢45CrNiMoVA硬车削加工性研究

2023中国汽车工程学会年会暨展览会

作者： qiu Yifan Yang Fan Wang Da Jiang Leixin Wang jianhang Wu Jiayu College of Automotive Engineering of Jilin University

The wheel system is an important part of the chassis structure,involving suspension,transmission,braking,*** wheel system is the bridge between the racecar and the ground through the tires,and it is the unsprung mass of the whole racecar,which is prone to failure under extreme working conditions with severe ***,it is of great importance to do research on its lightweight,stability and service life,which can improve the chassis dynamics,transmission stability and safety level of the *** paper mainly focuses on the design of the racecar wheel system based on spline connection and research on the service life of the spline,including how to determine the spline parameters,surface treatment process,and the influence of the rim center nut preload on the ***,combine with lightweight consideration,to determine the suitable structure design parameters of the *** safety factor is more than 1.8,the service life of the spline connection is more than 8600 km,and the weight is reduced by nearly1.5 kg compared to conventional friction *** analyzing the service life of the spline connection,the lightweight of the wheel system structure is improved while ensuring the service life,and the convenience of disassembly and installation is enhanced.

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兵工学报 2023年第3期44卷 773-782页

作者：杜凯焦黎颜培余建杭王玉彬仇天阳王西彬北京理工大学机械与车辆学院北京100081

为避免淬硬钢磨削工艺易引入残余拉应力以及大量使用切削液对环境造成严重污染的问题,采用硬车削代替磨削的加工方法。针对淬硬-回火45CrNiMoVA钢进行以车代磨工艺的研究,分析硬车削过程中的切削力、加工表面形貌、残余主应力及显微硬... 详细信息

为避免淬硬钢磨削工艺易引入残余拉应力以及大量使用切削液对环境造成严重污染的问题,采用硬车削代替磨削的加工方法。针对淬硬-回火45CrNiMoVA钢进行以车代磨工艺的研究,分析硬车削过程中的切削力、加工表面形貌、残余主应力及显微硬度。结果表明,切削力随切削深度和进给量的增大而增大,切削速度的改变对切削力的影响不大;硬车削后工件表面形貌一致性良好,表面粗糙度Ra值可达0.64μm;残余主应力随进给量和切削深度的增大而减小,随切削速度的增大先减小后增大;最大残余主应力的方向角随切削速度与切削深度的增大在37°~45°范围内保持稳定,随进给量的增大在22°~45°范围内先增大后保持稳定;表面显微硬度随切削速度的增大而减小,硬车削后表面显微硬度提高了13%,硬化层深度约200μm。

关键词： 45CrNiMoVA钢硬车削切削力表面形貌残余主应力显微硬度

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