Improved Conductivity and in Situ Formed Heterojunction via Zinc Doping in CuBi2O4 for Photoelectrochemical Water Splitting

• DOI: 10.1002/cphc.202300897
• Publication Date: 2024-02-07T12:05:06Z
• Authors: Yingfei Hu; Qingyuan Hu; Xianliu Chen; Mengting Zhao; Yumeng Wang; Hangmin Guan; Xuemin Hu; Yuanyuan Wang; Jianyong Feng
• Keywords: Photoelectrochemistry

Abstract As a photocathode with band gap of about 1.8 eV, copper bismuthate (CuBi 2 O 4 ) is promising material for photoelectrochemical (PEC) water splitting. However, weak charge transfer capability and severe carrier recombination suppress the PEC performance CuBi . In this paper, conductivity carriers transport are improved via introducing Zn 2+ into synthesis precursor , driving beneficial 110 mV positive shift onset potential in photocurrent. Detailed investigations demonstrate that introduction an appropriate amount zinc leads to situ segregation ZnO which serves as electron channel on surface forming heterojunctions. The synergistic effect heterojunctions doping simultaneously promotes concentration. OCP experiment proves ZnO/Zn−CuBi possesses better separation; Mott–Schottky curve shows significantly enhances concentration; lifetime calculated from time–resolved photoluminescence confirms faster extraction carriers.