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

Abstract

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 Ni 3 S 2 nanoflowers on a three-dimensional nanoporous CuAg substrate (Ni 3 S 2 @CuAg) for accelerating MOR. The nanoporous CuAg alloy substrate was prepared by dealloying of the metallic glassy (MG) alloy precursor, and the Ni 3 S 2 nanoflowers were in situ grown on the nanoporous CuAg skeleton through a simple electrodeposition process. The novel Ni 3 S 2 @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 Ni 3 S 2 @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 CH 3 OH solution. This work presents a novel strategy for designing electrocatalysts with high efficiency and durability for MOR.