Boosting Electrocatalytic Oxygen Evolution: Superhydrophilic/Superaerophobic Hierarchical Nanoneedle/Microflower Arrays of Ce x Co3- xO4 with Oxygen Vacancies

Yi Du; Haifang Tang; Danyu Zhang; Huiling Liu; Yuqing Chen; Zuoyan Zhu; Weijian Yang; Ziru Li; Yanhong Tang; Chengbin Liu

doi:10.1021/acsami.1c11662

Boosting Electrocatalytic Oxygen Evolution: Superhydrophilic/Superaerophobic Hierarchical Nanoneedle/Microflower Arrays of Ce _x Co_{3- x}O₄ with Oxygen Vacancies

ACS Appl Mater Interfaces. 2021 Sep 15;13(36):42843-42851. doi: 10.1021/acsami.1c11662. Epub 2021 Sep 6.

Authors

Yi Du^{1

2}, Haifang Tang³, Danyu Zhang¹, Huiling Liu¹, Yuqing Chen¹, Zuoyan Zhu¹, Weijian Yang¹, Ziru Li³, Yanhong Tang³, Chengbin Liu¹

Affiliations

¹ State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, P. R. China.
² College of Chemistry and Chemical Engineering, Anshun University, Anshun 561000, P. R. China.
³ College of Materials Science and Engineering, Hunan University, Changsha 410082, P. R. China.

PMID: 34482694
DOI: 10.1021/acsami.1c11662

Abstract

The oxygen evolution reaction has become the bottleneck of electrochemical water splitting for its sluggish kinetics. Developing high-efficiency and low-cost non-noble-metal oxide electrocatalysts is crucial but challenging for industrial application. Herein, superhydrophilic/superaerophobic hierarchical nanoneedle/microflower arrays of Ce-substituted Co₃O₄ (Ce_xCo_3-xO₄) in situ grown on the nickel foam are successfully constructed. The hierarchical architecture and superhydrophilic/superaerophobic interface can be facilely regulated by controlling the introduction of Ce into Co₃O₄. The unique feature of hierarchical architecture and superhydrophilic/superaerophobic interface is in favor of electrolyte penetration and bubbles release. In addition, the presence of oxygen vacancy and Ce endows the catalyst with enhanced intrinsic activity. Benefiting from these advantages, the optimized Ce_0.12Co_2.88O₄ catalyst shows a superior electrocatalytic performance for the oxygen evolution reaction (OER) with an overpotential of 282 mV at 20 mA cm^-2, and a Tafel slope of 81.4 mV dec^-1. The turnover frequency of 0.0279 s^-1 for Ce_0.12Co_2.88O₄ is 9.3 times larger than that for Co₃O₄ at an overpotential of 350 mV. Moreover, the optimized Ce_0.12Co_2.88O₄ catalyst shows a robust long-term stability in alkaline media.

Keywords: Ce doping; cobaltosic oxide; hierarchical architecture; oxygen evolution reaction; oxygen vacancy; superhydrophilic/superaerophobic interface.