Optimization and characterization of pulse electrodeposited nickel selenide nanostructure as a bifunctional electrocatalyst by response surface methodology

The electrocatalytic activity of the pulse electrodeposited NieSe coating on nickel foam (NF) for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) was optimized by design of experiments. In this study as the first step of optimization, the condition of electrodeposition bath containing the ratio of Se/Ni, pH, and temperature was optimized. The response surface methodology (RSM) in central composite design (CCD) was used for experiments based on the parameters of the ratio of Se/Ni and pH. The prediction model after carrying out the analyses of variance (ANOVA) on the responses showed the best desirable values for the ratio of Se/Ni and pH were 0.7 and 3.6. The nanostructure NieSe electrode electrodeposited in the optimal condition requires 103 and 249 mV (vs. RHE) for delivering 10 mA/cm(2) in HER and OER, respectively. To temperature survey, the optimized NieSe electrode was synthesized at 25, 40, and 60 degrees C. Results showed that the electrode electrodeposited at the ambient temperature with large electrochemically active surface area of 8960 and low Tafel slopes of 86 and 35 mV/dec has the superior electrocatalytic performance for HER and OER, respectively. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.