Hexagonal NiO nanosheets on Ni-foam as an electrocatalyst for high-performance water splitting application

Abstract

This study illustrates the catalytic hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities of the hexagonal NiO nanosheets on Ni-foam. The NiO electrocatalyst demonstrates the low over-potentials of 83 mV/380 mV and low Tafel slopes of 209 mV dec-(1)/299 mV dec(-1) during HER/OER, respectively. It also reveals excellent stability, showing a slight change in overpotentials of 116 mV and 430 mV during HER/OER after 2000 CV cycles. Electrochemical impedance spectroscopy spectra show the series resistance of 0.83 omega/1.04 omega and charge-transfer resistance of 1.63 omega/4.70 omega during HER/OER after 2000 CV cycles.