Nickel sulfide-oxide heterostructured electrocatalysts: Bi-functionality for overall water splitting and in-situ reconstruction

Zinan Huang; Liuqing He; Wenbiao Zhang; Wenjie Huang; Qijie Mo; Lichun Yang; Qiang Fu; Qingsheng Gao

doi:10.1016/j.jcis.2022.04.150

Nickel sulfide-oxide heterostructured electrocatalysts: Bi-functionality for overall water splitting and in-situ reconstruction

J Colloid Interface Sci. 2022 Sep 15:622:728-737. doi: 10.1016/j.jcis.2022.04.150. Epub 2022 Apr 30.

Authors

Zinan Huang¹, Liuqing He¹, Wenbiao Zhang¹, Wenjie Huang², Qijie Mo¹, Lichun Yang³, Qiang Fu⁴, Qingsheng Gao⁵

Affiliations

¹ College of Chemistry and Materials Science, and Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University Guangzhou 510632, PR China.
² School of Materials Science and Engineering, and Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou 510640, PR China.
³ School of Materials Science and Engineering, and Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou 510640, PR China; Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, PR China. Electronic address: mslcyang@scut.edu.cn.
⁴ Department of Mathematics, Physics, and Chemistry, Jiangxi College of Traditional Chinese Medicine, Fuzhou, Jiangxi 344000, PR China.
⁵ College of Chemistry and Materials Science, and Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University Guangzhou 510632, PR China. Electronic address: tqsgao@jnu.edu.cn.

PMID: 35537224
DOI: 10.1016/j.jcis.2022.04.150

Abstract

Bi-functional electrocatalysts are desired for both hydrogen and oxygen evolution reactions (HER and OER). Herein, facile O₂-plasma activation is introduced to improve the bi-functionality via constructing nickel sulfide-oxide heterostructures. Ni₃S₂-NiO_x supported by nickel foam delivers obviously elevated HER and OER activity in comparison with pristine Ni₃S₂ and recently reported NiS_x-based electrocatalysts, featured by the low overpotentials for HER (104 mV) and OER (241 mV) at ±10 mA cm^-2 in 1.0 M KOH, as well as a voltage of 1.52 V for overall water splitting. As revealed by in-situ Raman spectroscopy, on the one hand, Ni(OH)₂ generated from Ni₃S₂ during alkaline HER accelerates water dissociation toward the gradually improved performance; on the other hand, this heterostructure undergoes extensive oxidation during OER, leading to excessive NiOOH covering on Ni₃S₂ and thereby declining activity. These changes are interpreted by the distinct thermodynamic relationship under specific electrochemical conditions via density functional theory calculations.

Keywords: Bi-functional electrocatalysts; Heterostructures; In-situ reconstruction; Nickel sulfides; Overall water splitting.