Interface engineering: The Ni(OH) 2 /MoS 2 heterostructure for highly efficient alkaline hydrogen evolution

Earth-abundant, noble-metal-free catalysts with outstanding electrochemical hydrogen evolution reaction catalytic activity in alkaline media play a key role in sustainable production of H2 fuel. Herein, the novel three-dimensional Ni(OH)2/MoS2 hybrid catalyst with synergistic effect has been synthesized by a facile approach for efficient alkaline hydrogen evolution reaction. Benefiting from abundant active interfaces, this hybrid catalyst shows high hydrogen evolution catalytic activity in 1 M KOH aqueous solution with an onset overpotential of 20 mV, an overpotential of 80 mV at 10 mA cm−2 and a Tafel slope of 60 mV dec−1. Further theoretical calculations offers a deeper insight of the synergistic effect of Ni(OH)2/MoS2 interface: Ni(OH)2 provides the active sites for hydroxyl adsorption, and MoS2 facilitates adsorption of hydrogen intermediates and H2 generation. This interfacial cooperation leads to a favorable hydrogen and hydroxyl species energetics and reduce the energy barrier of the initial water dissociation step, which is the rate-limiting step of MoS2 catalyst in alkaline media. The combination of experimental and theoretical investigations demonstrates that the sluggish alkaline hydrogen evolution process can be circumvented by rational catalysts interface engineering.