Synthesis and Characterization of NiCo Bimetal Electrocatalyst for Water Splitting

Abstract

This research focuses on developing bimetallic nickel‑cobalt (NiCo) electrocatalysts for water‑splitting applications via a tailored electrodeposition approach using saccharin as a structure‑directing additive. The introduction of saccharin refined the material’s crystal size, promoted nickel enrichment in the alloy, and produced a smoother, more porous surface morphology, which collectively enhance the electrochemical active area. The modified catalyst exhibited improved catalytic activity for both hydrogen and oxygen evolution, displaying favorable onset potentials (-0.1593 V for HER and 1.6427 V for OER) and accelerated reaction kinetics, as reflected by Tafel slopes of 134.2 mV/dec and 24.96 mV/dec, respectively. While charge‑transfer resistance was not lowered, long‑term stability and corrosion resistance were markedly enhanced in the presence of saccharin. These results demonstrate that microstructural engineering through additive‑assisted electrodeposition can effectively boost the durability of NiCo electrocatalysts, underscoring the importance of morphology control for sustained performance in energy‑conversion systems.