Amorphous RuS2 electrocatalyst with optimized active sites for hydrogen evolution

Transition metal chalcogenides have attracted much attention as high-performance electrocatalysts for hydrogen evolution reaction (HER). Here, we synthesized an efficient HER electrocatalyst of amorphous ruthenium sulfide (A-RuS2), exhibiting an overpotential of 141 mV at the current density of 10 mA cm−2 and a Tafel slope of 65.6 mV dec−1. Experiments demonstrate amorphous RuS2 has much better catalytic activity than that of its crystalline counterparts. Our study shows that amorphous RuS2 has increased intrinsic activity and active sites. This work provides a feasible strategy for the development of HER electrocatalysts in amorphous state.