Hu Yingfei, Hu Qingyuan, Chen Xianliu, Zhao Mengting, Wang Yumeng, Guan Hangmin, Hu Xuemin, Wang Yuanyuan, Feng Jianyong
School of Materials Engineering, Jinling Institute of Technology, Nanjing, 211169, P. R. China.
Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, P. R. China.
Chemphyschem. 2024 Apr 16;25(8):e202300897. doi: 10.1002/cphc.202300897. Epub 2024 Feb 22.
As a photocathode with a band gap of about 1.8 eV, copper bismuthate (CuBiO) is a promising material for photoelectrochemical (PEC) water splitting. However, weak charge transfer capability and severe carrier recombination suppress the PEC performance of CuBiO. In this paper, the conductivity and carriers transport of CuBiO are improved via introducing Zn into the synthesis precursor of CuBiO, driving a beneficial 110 mV positive shift of onset potential in photocurrent. Detailed investigations demonstrate that the introduction of an appropriate amount of zinc leads to in situ segregation of ZnO which serves as an electron transport channel on the surface of CuBiO, forming heterojunctions. The synergistic effect of heterojunctions and doping simultaneously promotes the charge transfer and the carrier concentration. OCP experiment proves that ZnO/Zn-CuBiO possesses better charge separation; the Mott-Schottky curve shows that the doping of Zn significantly enhances the carrier concentration; carrier lifetime calculated from time-resolved photoluminescence confirms faster extraction of carriers.
作为一种带隙约为1.8电子伏特的光阴极，铋酸铜（CuBiO）是一种很有前景的光电化学（PEC）水分解材料。然而，其电荷转移能力较弱且载流子复合严重，抑制了CuBiO的PEC性能。本文通过在CuBiO的合成前驱体中引入锌来提高CuBiO的导电性和载流子传输能力，使光电流起始电位正向偏移110毫伏。详细研究表明，引入适量的锌会导致ZnO原位析出，其作为CuBiO表面的电子传输通道，形成异质结。异质结和掺杂的协同效应同时促进了电荷转移和载流子浓度。开路电位（OCP）实验证明ZnO/Zn-CuBiO具有更好的电荷分离效果；莫特-肖特基曲线表明锌的掺杂显著提高了载流子浓度；由时间分辨光致发光计算得到的载流子寿命证实了载流子的更快提取。
