Surface Reconstruction and Passivation of BiVO4 Photoanodes Depending on the "Structure Breaker" Cs

Chen Tao; Yi Jiang; Yunxuan Ding; Bingquan Jia; Ruitong Liu; Peifeng Li; Wenxing Yang; Lixin Xia; Licheng Sun; Biaobiao Zhang

doi:10.1021/jacsau.3c00100

Surface Reconstruction and Passivation of BiVO₄ Photoanodes Depending on the "Structure Breaker" Cs

JACS Au. 2023 Jul 13;3(7):1851-1863. doi: 10.1021/jacsau.3c00100. eCollection 2023 Jul 24.

Authors

Chen Tao¹, Yi Jiang¹, Yunxuan Ding^{2

3}, Bingquan Jia^{2

3}, Ruitong Liu², Peifeng Li², Wenxing Yang^{2

3}, Lixin Xia¹, Licheng Sun^{2

3}, Biaobiao Zhang^{2

3}

Affiliations

¹ College of Chemistry, Liaoning University, Shenyang 110036, Liaoning, China.
² Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310024, Zhejiang, China.
³ Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, Zhejiang, China.

Abstract

Monoclinic BiVO₄ is one of the most promising photoanode materials for solar water splitting. The photoelectrochemical performance of a BiVO₄ photoanode could be significantly influenced by the noncovalent interactions of redox-inert metal cations at the photoanode-electrolyte interfaces, but this point has not been well investigated. In this work, we studied the Cs⁺-dependent surface reconstruction and passivation of BiVO₄ photoanodes. Owing to the "structure breaker" nature of Cs⁺, the Cs⁺ at the BiVO₄ photoanode-electrolyte interfaces participated in BiVO₄ surface photocorrosion to form a Cs⁺-doped bismuth vanadium oxide amorphous thin layer, which inhibited the continuous photocorrosion of BiVO₄ and promoted surface charge transfer and water oxidation. The resulting cocatalyst-free BiVO₄ photoanodes achieved 3.3 mA cm^-2 photocurrent for water oxidation. With the modification of FeOOH catalysts, the photocurrent at 1.23 V_RHE reached 5.1 mA cm^-2, and a steady photocurrent of 3.0 mA cm^-2 at 0.8 V_RHE was maintained for 30 h. This work provides new insights into the understanding of Cs⁺ chemistry and the effects of redox-inert cations at the electrode-electrolyte interfaces.