Abstract: Using a coprecipitation method combined with a selenization strategy, we synthesized Prussian blue analogue (PBA) derived transition metal selenides-based (FeSe2, CoSe2, and FeSe2/CoSe2) composites and systematically evaluated the catalytic activity and stability of these three catalysts as cathodes for the hydrogen evolution reaction (HER) in alkaline electrolytes. The characterization of the synthesized catalysts were performed by using XRD, SEM, and XPS to determine it phase composition, morphology, and surface chemistry. The results indicate that the FeSe2/CoSe2 composite exhibits the most outstanding electrocatalytic hydrogen evolution performance, with an overpotential of only 118 mV at 10 mA cm?2 and a Tafel slope of only 86 mV dec?1. FeSe2/CoSe2 catalytic performance surpasses that of the single-phase FeSe2 and CoSe2, owing to the strong electronic coupling at the FeSe2/CoSe2 interface, which optimizes the electronic structure of FeSe2/CoSe2. After an 8 h CP test, the FeSe2/CoSe2 catalyst exhibited an overpotential retention rate of 91.74%, and the LSV curves of all three catalysts remained nearly unchanged after 1,000 CV cycles.

Key words: Hydrogen evolution reaction, Transition metal selenides, Electrocatalysis; Electrode materials, Prussian blue analogues