Stable overall water electrolysis performance of interface engineered Y2Ru2O7/NiMoO4@NF in alkaline solution

Abstract

Problems faced in water electrolysis, such as sluggish reaction kinetics and poor electrode stability, can be overcome by developing electrode materials with tailormade properties. Introducing a nanostructured interface with pyrochlore materials is an efficient but complex strategy. This study focused on the interface engineering of the pyrochlore Y2Ru2O7/NiMoO4@NF. The material was found to show significantly high overall water splitting performance in 1 M KOH electrolyte solution. Specifically, the prepared Y2Ru2O7/NiMoO4@NF showed oxygen evolution and hydrogen evolution overpotentials of 287 and 112 mV at a current density of 10 mA cm−2, respectively. A Y2Ru2O7/NiMoO4@NF electrode with higher stability that was prepared rationally required a cell voltage of only 1.613 V to achieve a current density of 10 mA cm−2 for alkaline water electrolysis. This showed the excellent catalytic ability of the electrode for overall water splitting. In particular, the temperature dependence of the electrode’s performance in water electrolysis in a practical water electrolyzer was examined to ascertain the electrode’s suitability for use on an industrial scale; the operating temperature of the electrolyzer was varied in the range 25–75 °C. The observed exceptional alkaline overall water splitting performance of the electrode resulted from the high charge mobility at the interface that enhanced synergy between Y2Ru2O7 and NiMoO4. The results of this study show that combining the metal oxides Y2Ru2O7 and NiMoO4 is a promising approach for preparing materials with high catalytic activity for use in alkaline overall water splitting.