Carbon hollow matrix anchored by isolated transition metal atoms serving as a single atom cocatalyst to facilitate the water oxidation kinetics of bismuth vanadate

Wenjie Zhang; Yujia Zhang; Hao Yuan; Jiaxin Li; Lei Ding; Shuai Chu; Lin Wang; Wei Zhai; Zhengbo Jiao

doi:10.1016/j.jcis.2022.02.096

Carbon hollow matrix anchored by isolated transition metal atoms serving as a single atom cocatalyst to facilitate the water oxidation kinetics of bismuth vanadate

J Colloid Interface Sci. 2022 Jun 15:616:631-640. doi: 10.1016/j.jcis.2022.02.096. Epub 2022 Feb 24.

Authors

Wenjie Zhang¹, Yujia Zhang², Hao Yuan¹, Jiaxin Li¹, Lei Ding¹, Shuai Chu¹, Lin Wang¹, Wei Zhai¹, Zhengbo Jiao³

Affiliations

¹ Institute of Materials for Energy and Environment, and College of Material Science and Engineering, Qingdao University, Qingdao 266071, China.
² State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, China.
³ Institute of Materials for Energy and Environment, and College of Material Science and Engineering, Qingdao University, Qingdao 266071, China. Electronic address: jiaozhb@qdu.edu.cn.

PMID: 35240441
DOI: 10.1016/j.jcis.2022.02.096

Abstract

Here, nitrogen doped carbon hollow matrix anchored by isolated transition metal atoms (M@NC, M = Fe, Co or Ni) are firstly utilized as new single atom cocatalysts (SACCs) to enhance the PEC performance of Mo, W ions co-doped BiVO₄ (Mo, W: BVO) through a simple spin-coating method. It is found that Mo, W: BVO modified with Fe@NC exhibits higher photocurrent density than the one decorated with Co@NC or Ni@NC due to the relatively low redox potential of Fe³⁺/Fe²⁺ (0.77 V vs SHE). During the photoelectrochemical (PEC) process, the Fe²⁺ ions are easier to accept the photogenerated holes of BVO and be oxidized to Fe³⁺ ions. Then, Fe³⁺ ions are reduced to Fe²⁺ again by accepting the electrons of water, and evolve oxygen simultaneously. Hence, Fe@NC could facilitate the water oxidation kinetics through the redox cycle of Fe ions and promote the charge separation efficiency by capturing the photogenerated holes. Theoretical calculations demonstrate that the deposition of Fe atoms make NC negatively charged, which is conducive to receiving the photogenerated holes. As a result, Mo, W: BVO/Fe@NC exhibits higher photocurrent density (3.2 mA/cm² vs RHE) than other BVO-based samples. This work opens up a new application field of SACCs serving as OER cocatalysts, and may provide a universal strategy to construct the efficient PEC photoelectrodes.

Keywords: BiVO(4); Cocatalyst; Photoelectrochemical; Single atom; Water splitting.