Vacancy and strain engineering of Co3O4 for efficient water oxidation

Jinyu Guo; Guangjin Wang; Shasha Cui; Bingying Xia; Zhijuan Liu; Shuang-Quan Zang

doi:10.1016/j.jcis.2022.08.160

Vacancy and strain engineering of Co₃O₄ for efficient water oxidation

J Colloid Interface Sci. 2023 Jan;629(Pt A):346-354. doi: 10.1016/j.jcis.2022.08.160. Epub 2022 Aug 29.

Authors

Jinyu Guo¹, Guangjin Wang², Shasha Cui¹, Bingying Xia¹, Zhijuan Liu³, Shuang-Quan Zang¹

Affiliations

¹ Henan Key Laboratory of Crystalline Molecular Functional Materials, Henan International Joint Laboratory of Tumor Theranostical Cluster Materials, Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
² School of Materials Science and Energy Engineering, Foshan University, Foshan 528000, China.
³ Henan Key Laboratory of Crystalline Molecular Functional Materials, Henan International Joint Laboratory of Tumor Theranostical Cluster Materials, Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou 450001, China. Electronic address: zhijuanliu@zzu.edu.cn.

PMID: 36081213
DOI: 10.1016/j.jcis.2022.08.160

Abstract

Co₃O₄ has been widely explored in electrocatalysis but seriously limited by its poor intrinsic ability. Defect engineering is an effective method to improve the electrocatalytic ability of catalysts by regulating electronic structure and optimizing the binding energy with surface adsorbates. Herein, in this work we have successfully integrated metal vacancies and tensile strain into Co₃O₄. With the formation of metal vacancies, the electronic structure of Co₃O₄ has been regulated. Moreover, the d-band center of Co₃O₄ has been modulated with the presence of tensile strain. The electrochemical oxygen evolution reaction (OER) ability of the obtained electrocatalyst was improved dramatically. The overpotential to reach 10 mA cm^-2 was only 327 mV. Reaction kinetics was rapidly facilitated as indicated by smaller Tafel slope and charge transfer resistance. Density Functional Theory (DFT) calculations revealed that the relocated atoms induced the formation of tensile strain and made d-band center of electrocatalyst near to Fermi level leading to enhanced the adsorption to reaction intermediates. What's more, the free energy barrier of rate-determining step (RDS) has been decreased with the integration of metal vacancies and tensile strain. This work provides an efficient strategy to develop defective and effective electrocatalysts.

Keywords: Co(3)O(4); Metal vacancy; OER; Tensile strain; d-band center.