Promoting Oxygen Evolution Reactions through Introduction of Oxygen Vacancies to Benchmark NiFe–OOH Catalysts

• Published in: ACS energy letters Vol. 3; no. 7; pp. 1515 - 1520
• Main Authors: Asnavandi, Majid, Yin, Yichun, Li, Yibing, Sun, Chenghua, Zhao, Chuan
• Format: Journal Article
• Language: English
• Published: American Chemical Society 13.07.2018
• ISSN: 2380-8195; 2380-8195
• DOI: 10.1021/acsenergylett.8b00696

Advanced electrocatalysts toward oxygen evolution reaction (OER) at high current density with low overpotential remain a significant challenge for electrochemical water splitting. Herein, NiFe-based catalysts with appropriate electronic conductivity and catalytic activity have been obtained through introduction of oxygen vacancies by a facile and economic NaBH4 reduction approach. The combined density functional theory calculations, physical characterization, and electrochemical studies disclose that the reductive treatment creates a high amount of oxygen vacancies, high active sites, and a low energy barrier for OER. The oxygen vacancy-rich catalyst yields a more than 2-fold increased current density (from 100 to 240 mA cm–2) at a low overpotential of 270 mV, accompanied by good stability under OER conditions. The approach is also broadly applicable for NiFe compounds synthesized via different methods or substrates.