Nanosheets of NiCo2O4/NiO as Efficient and Stable Electrocatalyst for Oxygen Evolution Reaction.

Abstract

Development of a stable catalyst that can efficiently function for longer time for energy conversion process in water splitting is a challenging work. Here, NiCo2O4/NiO nanosheets are successfully synthesized following a simple wet-chemical route, followed by the combustion technique. Finally, the synthesized catalyst NiCo2O4/NiO can function as an efficient catalyst for oxygen evolution reaction. Nanosheets with interconnections are very useful for better electron transportation because the pores in between the sheets are useful for the diffusion of electrolyte in electrocatalysis. In oxygen evolution reaction, these sheets can generate current densities of 10 and 20 mA/cm2, respectively, upon application of 1.59 and 1.62 V potential versus reversible hydrogen electrode (RHE) under alkaline condition. In contrast, bare NiCo2O4 nanowire bundles can generate a current density of 10 mA/cm2 upon application of 1.66 V versus RHE. The presence of NiO in NiCo2O4/NiO nanosheets helps to increase the conductivity, which further increases the electrocatalytic activity of NiCo2O4/NiO nanosheets.