A universal method to fabricate high-valence transition metal-based HER electrocatalysts and direct Raman spectroscopic evidence for interfacial water regulation.

Valence modulation of transition metal oxides represents a highly effective approach in designing high-performance catalysts, particularly for pivotal applications such as the hydrogen evolution reaction (HER) in solar/electric water splitting and the hydrogen economy. Recently, there has been a growing interest in high-valence transition metal-based electrocatalysts (HVTMs) due to their demonstrated superiority in HER performance, attributed to the fundamental dynamics of charge transfer and the evolution of intermediates. Nevertheless, the synthesis of HVTMs encounters considerable thermodynamic barriers, which presents challenges in their preparation.

Tunable d-band center of a NiFeMo alloy with enlarged lattice strain enhancing the intrinsic catalytic activity for overall water-splitting.

Developing efficient bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) under alkaline conditions is prospective for reducing energy consumption during water electrolysis. In this work, we successfully synthesized nanocluster structure composites composed of NiFeMo alloys with controllable lattice strain by the electrodeposition method at room temperature. The unique structure of NiFeMo/SSM (stainless steel mesh) facilitates the exposure of abundant active sites and promotes mass transfer and gas exportation.