In situ growth of NiO nanostructures supported on nickel foam as an efficient electrocatalyst for oxygen evolution reaction

Recently, the concerns about depletion of fossil fuels and also the environmental pollution resulting from resources burning have driven scientists to look for clean and sustainable energy resources. Some advantages of hydrogen have made it an alternative energy resource to fossil fuels. Electrochemically splitting of water is considered as one of the main techniques to produce high-purity hydrogen. Fabrication of cost-effective electrocatalysts for oxygen evolution reaction (OER) in a water splitting process is vital for large-scale practical applications. Herein, we present an affordable and straightforward method for synthesis of NiO nanoparticles supported on Ni foam for oxygen evolution reaction (OER). A single-step annealing process was carried out at different temperatures to achieve an optimal temperature, at which an electrocatalyst with a tailored morphology and high electrocatalytic activity is obtainable. The best electrocatalytic activity was achieved by the electrode fabricated at 400 °C, delivering current density of 10 mA/cm^2 at 1.59 mV potential versus reversible hydrogen electrode (RHE) under alkaline condition. Various material characterization tests accompanied by electrochemical measurements were used to clarify the excellent electrocatalytic activity of the electrode fabricated at 400 °C.