Effective Improvement of Thermodynamics and Kinetics of BiVO4 Photoanode via CuI for Photoelectrochemical Water Oxidation

Yuan Guan; Zheng Shen; Xinyi Gu; Dayu Wu; Shaomang Wang; Zhongyu Li; Shicheng Yan; Zhigang Zou

doi:10.1021/acs.langmuir.4c03658

Effective Improvement of Thermodynamics and Kinetics of BiVO₄ Photoanode via CuI for Photoelectrochemical Water Oxidation

Langmuir. 2024 Nov 19. doi: 10.1021/acs.langmuir.4c03658. Online ahead of print.

Authors

Yuan Guan¹, Zheng Shen¹, Xinyi Gu¹, Dayu Wu¹, Shaomang Wang², Zhongyu Li¹, Shicheng Yan³, Zhigang Zou³

Affiliations

¹ Jiangsu Province Key Laboratory of Fine Petrochemical Engineering, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, PR China.
² School of Urban Construction, Changzhou University, Changzhou 213164, PR China.
³ Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, PR China.

PMID: 39561331
DOI: 10.1021/acs.langmuir.4c03658

Abstract

The preparation of durable and efficient photoanodes for photoelectrochemical water oxidation is of great importance in promoting the development of green hydrogen production and artificial photosynthesis. Here, n-type BiVO₄ was combined with p-type CuI to construct a CuI/BiVO₄ (CIB-1) p-n heterojunction photoanode. The composite photoanode effectively overcame the drawbacks of BiVO₄, such as low separation and injection efficiency of photogenerated electron-hole pairs. As a result, the CIB-1 had the highest photocurrent density of 1.98 mA cm^-2, which was 2.5 times higher than pure BiVO₄ with 0.79 mA cm^-2 at 1.23 V (vs RHE) under AM 1.5G light irradiation. The CIB-1 had a lower Tafel slope of 23.2 mV decade^-1 compared to 47.9 mV decade^-1 for BiVO₄, so the water oxidation kinetics was remarkably advanced over CuI/BiVO₄. Based on DFT calculations, the OER overpotential of 0.480 V for CuI/BiVO₄ was significantly lower than that of 1.546 V for BiVO₄ due to the lower free energy from OH^- to oxygen over CuI/BiVO₄ compared to BiVO₄.