Ordered Ti-doped FeVO4 nanoblock photoanode with improved charge properties for efficient solar water splitting

Qingyi Zeng; Xijun Fu; Sheng Chang; Qingsong Zhang; Zhu Xiong; Yong Liu; Guowen Peng; Mi Li

doi:10.1016/j.jcis.2021.07.037

Ordered Ti-doped FeVO₄ nanoblock photoanode with improved charge properties for efficient solar water splitting

J Colloid Interface Sci. 2021 Dec 15:604:562-567. doi: 10.1016/j.jcis.2021.07.037. Epub 2021 Jul 9.

Authors

Qingyi Zeng¹, Xijun Fu², Sheng Chang³, Qingsong Zhang², Zhu Xiong³, Yong Liu⁴, Guowen Peng², Mi Li²

Affiliations

¹ School of Resources & Environment and Safety Engineering, University of South China, Hunan 421001, China; Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China. Electronic address: qingyizeng@usc.edu.cn.
² School of Resources & Environment and Safety Engineering, University of South China, Hunan 421001, China.
³ Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China.
⁴ School of Resources & Environment and Safety Engineering, University of South China, Hunan 421001, China. Electronic address: liuyong81668@163.com.

PMID: 34274717
DOI: 10.1016/j.jcis.2021.07.037

Abstract

Highly photoactive FeVO₄ photoanodes with ordered nanoblock morphology and uniform Ti-doping were prepared by drop-casting mixed Ti and V precursors onto FeOOH nanorod films and following an annealing process. The results indicate that Ti⁴⁺ is uniformly doped into the FeVO₄ lattice by substituting V⁵⁺ and provides an increased number of O₂^- vacancies. The optimized film thickness and doping level are 620 nm and 0.3%, respectively. Compared to the undoped sample, the Ti-doped photoanode showed ~ 219% enhancement in photocurrent at 1.0 V vs Ag/AgCl under back illumination of AM 1.5, reaching a state-of-the-art value of ~ 1.47 mA cm^-2, and also achieved stable and efficient overall water splitting activity with evolution rates of 28.3 and 14.1 μmol cm^-2h^-1 for H₂ and O₂, respectively. The excellent PEC performance could be attributed to the remarkably enhanced charge carrier concentration and conductivity, and the facilitated charge transfer kinetics across the semiconductor/electrolyte interface, as a result of Ti-doping.

Keywords: Drop-casting; FeVO(4); Nanoblock; Photoelectrochemical water splitting; Ti doping.