Synergic effects of FeOOH and CoNi2Se4 bilayer nanosheets as highly efficient electrocatalysts for the oxygen evolution reaction

Abstract

The substantial growth of nonprecious and inexpensive electrocatalysts for the oxygen evolution reaction (OER) is vital for commercial usage. In this work, cobalt nickel selenide (CoNi2Se4, called CNSe) thin film nanosheet heterojunctions with iron oxyhydroxide (FeOOH) thin film nanosheets were grown directly on a nickel foam substrate (Ni-foam) using an electrodeposition method. The electrocatalytic activity of CNSe/FeOOH bilayer nanosheets was evaluated for OER studies using its CNSe and FeOOH counterparts. The CNSe/FeOOH bilayer thin film exhibited a low overpotential of 222 mV to deliver a benchmark current density of 10 mA cm−2, which was lower than that of the CNSe (327 mV) and FeOOH (276 mV) electrocatalysts. The bilayer electrocatalyst delivered remarkable long-term electrochemical stability for more than 120 h at a constant current density of 10 mA cm−2. The excellent activity was attributed to the synergic effects of CNSe/FeOOH with high electrochemical active sites and feasible charge transfer ability. This study provides new insights for designing a different class of materials using a simple electrochemical deposition route for high-performance OER kinetics.