Directional Construction of a 1T0.63-MoSe2@MoP Multiphase-Interface Catalyst for Highly Efficient Alkaline Hydrogen Evolution.

Abstract

Alkaline water electrolysis is the most widely used technology for industrial hydrogen production. However, transition-metal dichalcogenides as inert alkaline hydrogen evolution electrocatalysts suffer from sluggish water adsorption and dissociation dynamics originating from the inappropriate intrinsic electronic structure. To address this issue, we report the synthesis of a type of multiphase-interface catalyst (MPIC), 1T0.63-MoSe2@MoP (1T = octahedral phase; MoSe2 = molybdenum selenide; MoP = molybdenum phosphide), that tunes the intrinsic interfacial electronic structure by multiphase synergy, promoting the alkaline hydrogen evolution reaction (HER). Consequently, the self-standing 1T0.63-MoSe2@MoP MPIC requires a small overpotential of 358 mV to reach a large current density of 1000 mA cm-2 in an alkaline freshwater electrolyte, along with impressive HER activity and stability at large current densities in an artificial alkaline seawater electrolyte. This work unravels the potential of Mo-based electrocatalysts for hydrogen evolution at high current densities, owing to the simple and mature synthesis process, which offers a vision to enable large-scale commercial hydrogen generation by seawater electrolysis. Meanwhile, density functional theory studies consistently confirm that the combination of metallic phase and intrinsic HER-active MoP in MoSe2 could successfully tune its electronic structure to improve the HER catalytic activity.