Surface oxidation protection strategy of CoS2 by V2O5 for electrocatalytic hydrogen evolution reaction

Jie Wu; Xuetao Qin; Yu Xia; Yuanyuan Zhang; Bin Zhang; Yunchen Du; Hsing-Lin Wang; Siwei Li; Ping Xu

doi:10.1039/d2nh00431c

Surface oxidation protection strategy of CoS₂ by V₂O₅ for electrocatalytic hydrogen evolution reaction

Nanoscale Horiz. 2023 Feb 27;8(3):338-345. doi: 10.1039/d2nh00431c.

Authors

Jie Wu^{1

2}, Xuetao Qin³, Yu Xia^{4

5}, Yuanyuan Zhang², Bin Zhang², Yunchen Du², Hsing-Lin Wang⁴, Siwei Li^{2

6}, Ping Xu²

Affiliations

¹ National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, Guangzhou 510640, China. yhwj1105914174@foxmail.com.
² MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China. pxu@hit.edu.cn.
³ Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering and College of Engineering, and BIC-ESAT, Peking University, Beijing 100871, China. xuetaoqin@pku.edu.cn.
⁴ Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China. wangxl3@sustech.edu.cn.
⁵ School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B152TT, UK. 11856005@mail.sustech.edu.cn.
⁶ Institute of Industrial Catalysis, School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China. lisiwei@xjtu.edu.cn.

PMID: 36633326
DOI: 10.1039/d2nh00431c

Abstract

Transition metal sulfides (TMSs) are promising electrocatalysts for hydrogen evolution reaction (HER), while TMSs usually suffer from inevitable surface oxidation in air, and the impact of the surface oxidation on their HER catalytic activity remains unclear. Herein, we demonstrate an effective strategy for reducing the surface oxidation degree of easily oxidized CoS₂ by introducing glued vanadium pentoxide (V₂O₅) nanoclusters, taking advantage of the preferential adsorption and strong interaction between high-valence V and O₂. Combining oxidation protection and elaborate oxidation control experiments reveal that reduced surface oxidation degree of CoS₂ is conducive to affording promising HER catalytic performance, as the oxidized surface of CoS₂ can hinder the dissociation of water and thus is harmful to the HER process. Direct evidence is provided that surface oxidation should be carefully considered for TMS-based HER catalysts. The present work not only develops a new strategy for protecting CoS₂ from surface oxidation, but also provides deep insight into the impact of surface oxidation on the HER performance of transition metal compounds.