Engineering Flower-like Ni3S2 on Nanoporous CuAg Alloy Heterostructure for Efficient Methanol Oxidation Reaction

Direct methanol fuel cells (DMFCs) have captured increasing attention as promising renewable energy devices. The development of innovative, cost-effective electrocatalysts with superior performance for the methanol oxidation reaction (MOR) holds great significance in promoting DMFCs. In this study, a facile dealloying–electrodeposition method was employed to fabricate stereospecific Ni3S2 nanoflowers on a three-dimensional nanoporous CuAg substrate (Ni3S2@CuAg) for accelerating MOR. The nanoporous CuAg alloy substrate was prepared by dealloying of the metallic glassy (MG) alloy precursor, and the Ni3S2 nanoflowers were in situ grown on the nanoporous CuAg skeleton through a simple electrodeposition process. The novel Ni3S2@CuAg catalysts exhibit outstanding catalytic performance for MOR owing to their preeminent conductivity, large specific surface area, and abundant active reaction sites. Notably, the optimal Ni3S2@CuAg-10 exhibited a superior current density of 340.5 mA cm–2 at 1 V along with good stability (93% current density retention after 2 h) in 1 M KOH and 1 M CH3OH solution. This work presents a novel strategy for designing electrocatalysts with high efficiency and durability for MOR.