Sequential Ni-Pt Decoration on Co(OH)₂ via Microwave Reduction for Highly Efficient Alkaline Hydrogen Evolution

A rapid solvent-free microwave-assisted strategy was developed to fabricate Pt- and Ni-modified Co(OH)₂ catalysts for alkaline hydrogen evolution. Among them, Ni-Pt@Co(OH)₂, prepared via sequential Ni-first then Pt loading, exhibited the best performance. Structural analyses confirmed uniform Pt dispersion with dominant Pt(111) facets, while ICP-MS showed reduced Pt usage compared to Pt@Co(OH)₂. Electrochemical measurements in 1.0 M KOH revealed an overpotential of 71 mV at 10 mA·cm-², comparable to Pt/C, and a mass activity 4-6.5 times higher across 25-75 mV. EIS demonstrated lower charge-transfer resistance, and stability tests showed negligible degradation after 3000 CV cycles and 11 h continuous operation. The outstanding performance arises from enhanced Pt utilization, abundant conductive sites, and strong Ni-Pt interfacial synergy, highlighting Ni-Pt@Co(OH)₂ as a promising catalyst for efficient alkaline HER with reduced Pt consumption.