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 Ni 3 S 2 /Cr 2 S 3 nanosheets on nickel foam (Ni 3 S 2 /Cr 2 S 3 /NF) for high current HER electrocatalysis in alkaline media . As-prepared Ni 3 S 2 /Cr 2 S 3 /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 Ni 3 S 2 /Cr 2 S 3 /NF remained almost unchanged. This impressive HER performance stems from its unique hybridization nature enabled hydrogen spillover, in which Cr 2 S 3 efficiently catalyzes the Volmer step, i.e., water dissociation to generate hydrogen, and the latter further transports to neighboring Ni 3 S 2 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.