Nickel–Iron Bimetal as a Cost-Effective Cocatalyst for Light-Driven Hydrogen Release from Methanol and Water

Light-driven hydrogen evolution from liquid hydrogen carriers offers an innovative solution for the realization of safe storage and transportation of hydrogen. The exploration of efficient and cost-effective cocatalysts is highly desirable for constructing an affordable light-driven catalytic architecture. In this work, nickel–iron bimetal (NiFe) is rationally designed and then supported by gallium nitride nanowires (GaN NWs)/Si for light-driven hydrogen generation from methanol aqueous solution. Under optimized conditions, the H2 evolution rate of NiFe is even comparable to noble metals, e.g., Pt, Ru. By correlative operando spectroscopy characterizations, with density functional theory calculations, it is discovered that Fe is cooperative with Ni for dramatically lowering the energy barrier of the potential-limiting step of *CHO → *CO. What is more, by coordination of photoexcited charge carriers with photothermal effect, the production of hydrogen from CH3OH/H2O is evidently improved via the evolving track of *CH3O > *CH2O/*CHO > *CO > *CO2, in concurrent H2O dissociation toward ·OH. Combined with the superior optical and electronic attributes of the GaN NWs/Si semiconductor platform, NiFe bimetal enables the achievement of a marked hydrogen activity of 61.2 mmol g–1 h–1 by the only input of light under ambient conditions. This study presents a promising strategy for hydrogen release from liquid hydrogen carriers by using earth-abundant materials under mild conditions.