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 CoS 2 -MoS 2 heterostructure is synthesized, where MoS 2 nanosheets are vertically anchored on CoS 2 microflakes. Plentiful heterogeneous nanointerfaces generated between MoS 2 and CoS 2 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 CoS 2 -MoS 2 toward HER in acidic and alkaline solutions simultaneously, in terms of the overpotential in 0.5 M H 2 SO 4 (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. [Display omitted] • Fabrication of CoS 2 -MoS 2 heterostructure via an interface-induced approach. • The first 2D–2D heterostructure of CoS 2 -MoS 2 towards efficient HER in wide-pH media. • Synergistic modulation of electronic and geometric structures for a superb dual-pH HER. [ABSTRACT FROM AUTHOR]