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  

Modulating band alignment at the 3D metal/semiconductor interface of liquid metal-embraced semiconductor photoelectrodes for water splitting

作　　者：陈祥涛 甄超 邱建航 李娜 贾楠 刘岗 Xiangtao Chen;Chao Zhen;Jianhang Qiu;Na Li;Nan Jia;Gang Liu(Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education),School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China)

机构地区：[1]Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education),School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China [2]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [3]School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China

出　　处：《Science China Materials》2024年第6期1804-1811,共8页中国科学（材料科学）（英文版）

基　　金：financially supported by the National Key R&D Program of China (2021YFA1500800);the National Natural Science Foundation of China (52072377,and 51825204);the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2020192);the CAS Projects for Young Scientists in Basic Research (YSBR-004);the financial support from the New Cornerstone Science Foundation through the XPLORER PRIZE。

摘　　要：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.The transfer of photogenerated charges from semiconductors as photoabsorbers to conductive substrates as current collectors is closely correlated with the interface band alignment,particularly for an emerging class of photoelec-trodes possessing the three dimensional(3D)interface that semiconductors are embraced by low-melting-point(LMP)metals(i.e.,Field’s metals).Herein,the interface band align-ment is modulated to promote the transfer of photogenerated charges by taking advantage of the composition-dependent work function(WF)of liquid metal as the current collector.It is found that embracing ZnO particles by indium tin(IT)alloy leads to the Ohmic contact,while embracing ZnO particles by bismuth indium tin(BIT)alloy leads to the Schottky contact.Consequently,the photocurrent density of the resulting IT-embraced ZnO(IT/ZnO)photoelectrode with superior charge collection and separation ability for photoelectrochemical water splitting is increased by 19%from 0.52 mA cm^(-2) of BIT-embraced ZnO(BIT/ZnO)to 0.62 mA cm^(-2),ranging on the top of the representative ZnO photoelectrodes.In contrast,the photoelectrodes of WO3,TiO_(2),and Cu2O embraced with IT or BIT have the same contact type and nearly identical perfor-mance.This work demonstrates the potential of changing the metal/semiconductor contact type to enhance the performance of LMP metal-embraced semiconductor photoelectrodes by choosing liquid metals with different WFs,paving a way to build efficient photoelectrodes.

关 键 词：metal-embraced photoelectrodes 3D interfaces Oh-mic contact water splitting 

分 类 号：O644.1[理学—物理化学] TQ116.2[理学—化学]