MOF-derived S-doped NiCo2O4 hollow cubic nanocage for highly efficient electrocatalytic oxygen evolution

Jiabing Luo; Xingzhao Wang; Shutao Wang; Wenle Li; Yanpeng Li; Tingyong Wang; Fengqi Xu; Yang Liu; Yan Zhou; Jun Zhang

doi:10.1016/j.jcis.2023.11.094

MOF-derived S-doped NiCo₂O₄ hollow cubic nanocage for highly efficient electrocatalytic oxygen evolution

J Colloid Interface Sci. 2024 Feb 15:656:297-308. doi: 10.1016/j.jcis.2023.11.094. Epub 2023 Nov 17.

Authors

Jiabing Luo¹, Xingzhao Wang², Shutao Wang³, Wenle Li¹, Yanpeng Li³, Tingyong Wang², Fengqi Xu², Yang Liu⁴, Yan Zhou⁵, Jun Zhang⁶

Affiliations

¹ School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China.
² SunRui Marine Environment Engineering Co., Ltd, Qingdao 266100, China.
³ State Key Laboratory of Heavy Oil Processing, School of Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China.
⁴ Qingdao Shichuang Technology Co., Ltd, Qingdao 266499, China.
⁵ School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China. Electronic address: yanzhou@upc.edu.cn.
⁶ School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China; State Key Laboratory of Heavy Oil Processing, School of Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China.

PMID: 37995400
DOI: 10.1016/j.jcis.2023.11.094

Abstract

Inducing the surface reconstruction of spinels is critical for improving the electrocatalytic oxygen evolution reaction (OER) activity. Herein, S-doped NiCo₂O₄ hollow cubic nanocage was synthesized by anion etching Metal-Organic Frameworks (MOFs) template and air annealing strategies. The hollow structure possesses a large specific surface area and pore size, facilitating active site exposure and mass transport. S^2- doping regulates the electronic structure, reducing the oxidation potential of Ni sites during the OER process, thus promoting the surface reconstruction into γ-NiOOH active species. Meanwhile, S^2- doping enhances conductivity, accelerating interfacial charge transfer. As a result, S-NiCo₂O₄-6 exhibits superior OER activity (262 mV overpotential @ 10 mA cm^-2) and stability in 1.0 M KOH solution. Furthermore, 20 % Pt/C‖S-NiCo₂O₄-6 only needs 1.832 V to achieve 50 mA (the electrochemical active area is 4 cm²) in a homemade anion exchange membrane (AEM) electrolyzer. This work proposes a novel approach for preparing efficient anion-doped spinel-based OER electrocatalysts.

Keywords: Anion exchange; Doping; Electronic structure; Oxygen evolution reaction; Spinel oxides.