Fabrication of CoS2-MoS2 heterostructure via interface engineering toward efficient dual-pH hydrogen evolution

Modulation of electronic structure via heterointerface engineering is regarded as an appealing strategy to promote the hydrogen evolution reaction (HER) performance of a pH-universal electrocatalyst. Herein, the CoS2-MoS2 heterostructure is synthesized, where MoS2 nanosheets are vertically anchored on CoS2 microflakes. Plentiful heterogeneous nanointerfaces generated between MoS2 and CoS2 phases not only provide sufficient electroactive sites and structural defects, but also afford a hierarchically porous structure. The synergistic modulation of electronic and geometric structures accounts for a superb catalytic activity and long-durability of CoS2-MoS2 toward HER in acidic and alkaline solutions simultaneously, in terms of the overpotential in 0.5 M H2SO4 (218 mV versus RHE) and 1.0 M KOH (251 mV) at a current density of 10 mA cm−2. This work offers an exciting avenue for fabricating transition metal sulfides as efficient wide-pH electrocatalysts through an interface-induced strategy.