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 CuBi2O4(np-CBO)photocathodes and engineered their surface point defects via rapid thermal processing(RTP)in controlled atmospheres(O2,N2,and vacuum).We found that the O2-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 anal-yses revealed that the amounts of oxygen vacancies(Vo)and Cu1+were reduced simultaneously,and the relative electrochemical active surface area increased after the O2-RTP treatment.Notably,the point defects(VCu,Cu1+,and Vo)regulated np-CBO achieved a superb water-splitting photocurrent density of-1.81 mA cm-2 under simulated sunlight illumination,which is attributed to the enhanced charge trans-port 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(O2-N2-O2-N2),demonstrat-ing 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.

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

Department of Materials Science&Engineering,Ajou University,Suwon 16499,South Korea;Department of Energy Systems Research,Ajou University,Suwon 16499,South Korea;Department of Nanotechnology and Advanced Materials Engineering,Sejong University,Seoul 05006,South Korea

能源化学

[1]Li Qu;Runfa Tan;Arumugam Sivanantham;Min Je Kang;Yoo Jae Jeong;Dong Hyun Seo;Sungkyu Kim;In Sun Cho-.Point-defect engineering of nanoporous CuBi2O4 photocathode via rapid thermal processing for enhanced photoelectrochemical activity)[J].能源化学,2022(08):201-209

photocathodes,VCu,Cu1+were,Cu1+,demonstrat

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