Nitriding-reduction fabrication of coralloid CoN/Ni/NiO for efficient electrocatalytic overall water splitting

Deling Wang; Chao Zhang; Jinguang Hu; Tao Zhuang; Zhiguo Lv

doi:10.1016/j.jcis.2023.11.018

Nitriding-reduction fabrication of coralloid CoN/Ni/NiO for efficient electrocatalytic overall water splitting

J Colloid Interface Sci. 2024 Feb:655:217-225. doi: 10.1016/j.jcis.2023.11.018. Epub 2023 Nov 4.

Authors

Deling Wang¹, Chao Zhang², Jinguang Hu³, Tao Zhuang⁴, Zhiguo Lv⁵

Affiliations

¹ State Key Laboratory Base for Eco-chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
² State Key Laboratory Base for Eco-chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China; Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, Guangxi University, Nanning 530004, China. Electronic address: chaozhangchem@qust.edu.cn.
³ Department of Chemical & Petroleum Engineering, Schulich School of Engineering, Calgary, Alberta T2N 1N4, Canada.
⁴ Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, Shandong, China. Electronic address: zhuangtao@qust.edu.cn.
⁵ State Key Laboratory Base for Eco-chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China. Electronic address: lvzhiguo@qust.edu.cn.

PMID: 37939405
DOI: 10.1016/j.jcis.2023.11.018

Abstract

The introduction of nitride in Ni/NiO-based catalytic system for electrocatalystic water splitting via a skillful strategy remains a great challenge. Herein, we proposed a one-step urea nitriding-reduction strategy for the fabrication of novel CoN/Ni/NiO electrocatalyst on carbon cloth (CC). The combination of CoN and Ni/NiO could construct CoN/Ni interface and expose more active sites, thus exhibiting excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in alkaline media. Consequently, CoN/Ni/NiO catalyst exhibited remarkable HER/OER performance with an overpotential of 92 mV/114 mV at 10 mA cm^-2 in 1.0 M KOH, along with a low cell voltage of 1.56 V to enhance overall water splitting. In addition, when CoN was introduced in Ni/NiO system, CoN/Ni/NiO displayed high conductivity, large active surface areas, high Faradic efficiency (FE) and remarkable stability. Density functional theory (DFT) calculations demonstrated that CoN/Ni/NiO possessed a decreased d-band center beneficial for optimizing the energy barrier of intermediates. Specifically, the ΔG_H2O (0.088 eV) and ΔG_H* (0.18 eV) in HER and the ΔG_OOH* (1.4 eV) of rate determining step (O*→OOH*) in OER of CoN/Ni/NiO catalyst were optimized to achieve high water splitting activity. Simultaneously, for adsorbed H₂O on CoN/Ni/NiO, the OH bond length extended from 0.975 to 1.110 Å, and the bond angle enlarged from 104.271 to 109.471°, thereby directly demonstrating the excellent HER/OER performance of CoN/Ni/NiO.

Keywords: CoN; Electrocatalyst; HER/OER; Ni/NiO; Overall water splitting.