Synergistic Effect of Allium-like Ni9 S8 & Cu7 S4 Electrodeposited on Nickel Foam for Enhanced Water Splitting Activity

M Mottakin; Vidhya Selvanathan; Md Ariful Islam; Hamad Almohamadi; Nabeel H Alharthi; Satoru Yoshimura; Md Akhtaruzzaman

doi:10.1002/asia.202300532

Synergistic Effect of Allium-like Ni₉ S₈ & Cu₇ S₄ Electrodeposited on Nickel Foam for Enhanced Water Splitting Activity

Chem Asian J. 2023 Aug 6:e202300532. doi: 10.1002/asia.202300532. Online ahead of print.

Authors

M Mottakin^{1

2}, Vidhya Selvanathan³, Md Ariful Islam¹, Hamad Almohamadi⁴, Nabeel H Alharthi^{5

6}, Satoru Yoshimura⁷, Md Akhtaruzzaman^{1

7

8}

Affiliations

¹ Solar Energy Research Institute (SERI, Universiti Kebangsaan Malaysia (UKM) (@ The National University of Malaysia), Bangi, 43600, Selangor, Malaysia.
² Dept. of Applied Chemistry and Chemical Engineering, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj, 8100, Bangladesh.
³ Institute of Sustainable Energy, Universiti Tenaga Nasional (The Energy University) Jalan Ikram-Uniten, Kajang, 43000, Selangor, Malaysia.
⁴ Department of Chemical Engineering, Faculty of Engineering, Islamic University of Madinah, Madinah, 41411, Kingdom of Saudi Arabia.
⁵ Department of Mechanical Engineering, Faculty of Engineering, Islamic University of Madinah, Madinah, 41411, Kingdom of Saudi Arabia.
⁶ Mechanical Engineering Department, College of Engineering, King Saud University, Riyadh, 11421, Kingdom of Saudi Arabia.
⁷ Research Center of Advanced Materials for Breakthrough Technology, Graduate School of Engineering Science, Akita University, 1-1 Tegatagakuen-machi, Akita City, 010-8502, Japan.
⁸ Graduate School of Pure and Applied Sciences, University of Tsukuba Tsukuba, Ibaraki, 305-8573, Japan.

PMID: 37544903
DOI: 10.1002/asia.202300532

Abstract

This study explores a water-splitting activity using a biphasic electrodeposited electrode on nickel foam (NF). The *Ni₉ S₈ /Cu₇ S₄ /NF electrode with citric acid reduction exhibits superior OER (oxygen evolution reaction) and HER (hydrogen evolution reaction) performance with reduced overpotential and a steeper Tafel slope. The *Ni₉ S₈ /Cu₇ S₄ /NF electrode displays the ultra-low overpotential value of 212 mV for OER and 109 mV for HER at the current density of 10 mA cm^-2 . The Tafel slope of 25.4 mV dec^-1 for OER and 108 mV dec^-1 for HER was found from that electrode. The maximum electrochemical surface area (ECSA), lowest series resistance and lowest charge transfer resistance are found in citric acid reduced electrode, showing increased electrical conductivity and quick charge transfer kinetics. Remarkably, the *Ni₉ S₈ /Cu₇ S₄ /NF electrode demonstrated excellent stability for 80 hours in pure water splitting and 20 hours in seawater splitting. The synergistic effect of using bimetallic (Cu&Ni) sulfide and enhanced electrical conductivity of the electrode are caused by reduction of metal sulfide into metallic species resulting in improved water splitting performance.

Keywords: Biphasic design; Electrocatalyst; Electrodeposition; Water Splitting.

Grants and funding

RS-2022-004/Universiti Kebangsaan Malaysia (UKM)