High current density hydrogen evolution on heterostructured Ni/Cr bimetallic sulfide catalyst in alkaline media

It remains challenging to design alkaline hydrogen evolution reaction (HER) electrocatalyst able to stably operate at ampere-level current density. In this work, we successfully synthesized heterostructured Ni3S2/Cr2S3 nanosheets on nickel foam (Ni3S2/Cr2S3/NF) for high current HER electrocatalysis in alkaline media. As-prepared Ni3S2/Cr2S3/NF reaches 0.5 and 1.0 A cm−2 currents at 230 and 333 mV overpotential, respectively. After 50 h test at 0.5 A cm−2, the potential of Ni3S2/Cr2S3/NF remained almost unchanged. This impressive HER performance stems from its unique hybridization nature enabled hydrogen spillover, in which Cr2S3 efficiently catalyzes the Volmer step, i.e., water dissociation to generate hydrogen, and the latter further transports to neighboring Ni3S2 via spillover to facilitate the molecular hydrogen formation. This work provides a feasible strategy to synthesize efficient and durable HER catalysts for ampere-level water splitting.