Point-defect engineering of nanoporous CuBi_(2)O_(4) photocathode via rapid thermal processing for enhanced photoelectrochemical activity  

作　　者：Li Qu Runfa Tan Arumugam Sivanantham Min Je Kang Yoo Jae Jeong Dong Hyun Seo Sungkyu Kim In Sun Cho 

机构地区：[1]Department of Materials Science&Engineering,Ajou University,Suwon 16499,South Korea [2]Department of Energy Systems Research,Ajou University,Suwon 16499,South Korea [3]Department of Nanotechnology and Advanced Materials Engineering,Sejong University,Seoul 05006,South Korea

出　　处：《Journal of Energy Chemistry》2022年第8期201-209,I0007,共10页能源化学（英文版）

基　　金：supported by the Basic Science Research Program through the National Research Foundation of Korea,funded by the Ministry of Science,ICT,and Future Planning(NRF Award No.NRF-2019R1A2C2002024 and 2021R1A4A1031357);supported by the Basic Science Research Program through NRF funded by the Ministry of Education(NRF Award No.NRF2020R1A6A1A03043435)。

摘　　要：Engineering point defects such as metal and oxygen vacancies play a crucial role in manipulating the electrical,optical,and catalytic properties of oxide semiconductors for solar water splitting.Herein,we synthesized nanoporous CuBi_(2)O_(4)(np-CBO)photocathodes and engineered their surface point defects via rapid thermal processing(RTP)in controlled atmospheres(O_(2),N_(2),and vacuum).We found that the O_(2)-RTP treatment of np-CBO increased the charge carrier density effectively without hampering the nanoporous morphology,which was attributed to the formation of copper vacancies(VCu).Further analyses revealed that the amounts of oxygen vacancies(Vo)and Cu^(1+)were reduced simultaneously,and the relative electrochemical active surface area increased after the O_(2)-RTP treatment.Notably,the point defects(VC_(u),Cu^(1+),and Vo)regulated np-CBO achieved a superb water-splitting photocurrent density of-1.81 m A cm^(-2) under simulated sunlight illumination,which is attributed to the enhanced charge transport and transfer properties resulting from the regulated surface point defects.Finally,the reversibility of the formation of the point defects was checked by sequential RTP treatments(O_(2)-N_(2)-O_(2)-N_(2)),demonstrating the strong dependence of photocurrent response on the RTP cycles.Conclusively,the surface point defect engineering via RTP treatment in a controlled atmosphere is a rapid and facile strategy to promote charge transport and transfer properties of photoelectrodes for efficient solar water-splitting.

关 键 词：NANOPOROUS Copper bismuth oxide Rapid thermal processing Copper vacancy Charge transport 

分 类 号：O646.541[理学—物理化学]