Constructing Ni₄W/WO₃/NF with strongly coupled interface for hydrogen evolution in alkaline media

The pursuit of storing renewable electricity in chemical bonds has encouraged the effort toward developing efficient electrocatalysts for alkaline hydrogen production. However, the additional step of water dissociation under alkaline conditions frequently limits the performance of electrocatalysts in alkaline media. Herein, we synthesize Ni₄W/WO₃ with a strongly coupled interface on the Ni foam (NF) by phase transition of NiWO₄, to enhance the activity for alkaline hydrogen production. It is discovered that the strong binding hydroxyl on WO₃ sites facilitates the dissociation of water, which in turn promotes hydrogen evolution through the synergy effect of strong adsorption of H on Ni sites. The adsorption/desorption energy of Ni sites is further tuned by the formation of intermetallic Ni₄W. Owing to the three-dimensional structure and tailored composition, the Ni₄W/WO₃/NF electrocatalyst exhibits a low overpotential of 31 mV at a current density of 10 mA·cm⁻², with a Tafel slope of 38 mV·dec⁻¹. This work provides new opportunities to modulate the catalytic performance of Ni-based electrocatalysts by signifying the metal-oxide interface.