Ultrathin Spinel-Structured Nanosheets Rich in Oxygen Deficiencies for Enhanced Electrocatalytic Water Oxidation.

Abstract

Electrochemical water splitting is a clean technology for H2 fuels, but greatly hindered by the slow kinetics of the oxygen evolution reaction (OER). Herein, a series of spinel-structured nanosheets with oxygen deficiencies and ultrathin thicknesses were designed to increase the reactivity and the number of active sites of the catalysts, which were then taken as an excellent platform for promoting the water oxidation process. Theoretical investigations showed that the oxygen vacancies confined in the ultrathin nanosheet could lower the adsorption energy of H2O, leading to increased OER efficiency. As expected, the NiCo2O4 ultrathin nanosheets rich in oxygen vacancies exhibited a large current density of 285 mA cm(-2) at 0.8 V and a small overpotential of 0.32 V, both of which are superior to the corresponding values of bulk samples or samples with few oxygen deficiencies and even higher than those of most reported non-precious-metal catalysts. This work should provide a new pathway for the design of advanced OER catalysts.

• Authors: Jian Bao, Xiaodong Zhang, Bo Fan, Jiajia Zhang, Min Zhou, Wenlong Yang, Xin Hu, Hui Wang, Bicai Pan, Yi Xie
• Journal: Angewandte Chemie (International ed. in English) (Angew Chem Int Ed Engl) Vol. 54 Issue 25 Pg. 7399-404 (Jun 15 2015) ISSN: 1521-3773 [Electronic] Germany
• PMID: 25951435 (Publication Type: Journal Article)
• Copyright: © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.