Affiliation:
1. School of Materials and Chemical Technology, Tokyo Institute of Technology 1 , Tokyo 152-8552, Japan
2. Department of Chemistry, The University of Tokyo 2 , 113-0033 Tokyo, Japan
Abstract
The development of water electrolysis catalysts that accelerate the oxygen evolution reaction (OER) is a crucial challenge. Ni-based oxides are promising OER catalysts; however, quantitative studies of Ni-based oxides remain unexplored. In this study, we quantitatively evaluated the OER activity of LiNi0.5Mn1.5O4 as a thin-film electrode catalyst. The LiNi0.5Mn1.5O4 thin film fabricated using a sputtering method exhibited a current density of 6.6 and ∼2.6 mAcm−2 for geometric and estimated areas, respectively, at 1.78 V vs. a reversible hydrogen electrode. X-ray photoelectron spectroscopy indicated the presence of Ni3+ in the as-grown and post-OER LiNi0.5Mn1.5O4 thin films. These results suggest that Ni3+ plays a key role in the OER of LiNi0.5Mn1.5O4.
Funder
Japan Society for the Promotion of Science
Precursory Research for Embryonic Science and Technology
Core Research for Evolutional Science and Technology
Ministry of Education, Culture, Sports, Science and Technology