Activating a TiO2/BiVO4 Film for Photoelectrochemical Water Splitting by Constructing a Heterojunction Interface with a Uniform Crystal Plane Orientation

Canjun Liu; Linmei Chen; Xin Su; Shu Chen; Jie Zhang; Heping Yang; Yong Pei

doi:10.1021/acsami.1c20038

Activating a TiO₂/BiVO₄ Film for Photoelectrochemical Water Splitting by Constructing a Heterojunction Interface with a Uniform Crystal Plane Orientation

ACS Appl Mater Interfaces. 2022 Jan 12;14(1):2316-2325. doi: 10.1021/acsami.1c20038. Epub 2021 Dec 29.

Authors

Canjun Liu^{1

2}, Linmei Chen¹, Xin Su¹, Shu Chen¹, Jie Zhang¹, Heping Yang³, Yong Pei²

Affiliations

¹ Key Laboratory of Theoretical Organic Chemistry and Function Molecule of Ministry of Education, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China.
² School of Chemistry, Xiangtan University, Xiangtan 411105, China.
³ Xiangtan Central Hospital, Xiangtan 411199, Hunan, China.

PMID: 34965083
DOI: 10.1021/acsami.1c20038

Abstract

The construction of a heterojunction has been considered one of the most effective strategies to improve the photoelectrochemical (PEC) performance of photoanodes; however, most researchers only focus on the design and preparation of a novel and efficient heterojunction photoelectrode, and the investigation on the effect of the heterojunction interface structure on PEC performance is ignored. In this work, a TiO₂/BiVO₄ photoanode with a uniform crystal plane orientation in the heterojunction interface (TiO₂-110/BiVO₄-202) was prepared by an in situ transformation method. We found that the PEC activity of the TiO₂/BiVO₄ photoanode can be activated by constructing such a heterojunction interface. Compared with a TiO₂/BiVO₄ photoanode with a random crystal plane orientation prepared by a simple soaking-calcining method (S-TiO₂/BiVO₄, 0.04 mA/cm² at 1.23 V_RHE), the TiO₂/BiVO₄ photoanode prepared by the in situ transformation method (I-TiO₂/BiVO₄) exhibits a significantly better PEC performance, and the photocurrent density of I-TiO₂/BiVO₄ is about 2.2 mA/cm² at 1.23 V_RHE under visible light irradiation without a cocatalyst. This is mainly attributed to the fact that I-TiO₂/BiVO₄ has a faster electron transfer rate in the heterojunction interface according to the results of PEC analysis. Furthermore, density functional theory (DFT) calculations show that the BiVO₄-202 surface has a higher Fermi energy level, thereby expediting the photogenerated carrier transport in the heterojunction interface. This work corroborates and strengthens the view that the heterojunction interface structure has a significant effect on the PEC performance.

Keywords: BiVO4; TiO2; heterojunction interface; photoelectrochemical; water splitting.