Electrocatalytic Water Splitting through the Ni S Self-Grown Superstructures Obtained via a Wet Chemical...

We report water-splitting application of chemically stable self-grown nickel sulfide (Ni S ) electrocatalysts of different nanostructures including rods, flakes, buds, petals, etc., synthesized by a hydrothermal method on a three-dimensional Ni foam (NiF) in the presence of different sulfur-ion precursors, e.g., thioacetamide, sodium thiosulfate, thiourea, and sodium sulfide. The S^2- ions are produced after decomposition from respective sulfur precursors, which, in general, react with oxidized Ni²⁺ ions from the NiF at optimized temperatures and pressures, forming the Ni S superstructures. These Ni S electrocatalysts are initially screened for their structure, morphology, phase purity, porosity, and binding energy by means of various sophisticated instrumentation technologies. The as-obtained Ni S electrocatalyst from sodium thiosulfate endows an overpotential of 200 mV. The oxygen evolution overpotential results of Ni S electrocatalysts are comparable or superior to those reported previously for other self-grown Ni S superstructure morphologies.