Raspberry-like Rh-NiFeO_x quantum dots for enhanced alkaline hydrogen evolution reaction

Electrochemical water splitting offers promises for sustainable hydrogen production and decarbonization. However, the state-of-the-art noble metal catalysts for the hydrogen evolution reaction (HER) suffer from low mass activity and sluggish reaction kinetics in alkaline environments, constraining large-scale application. Herein, we synthesize raspberry-like Rh-NiFeO_x quantum dots with uniformly dispersed Rh nanoclusters (<2 nm) on the surface of NiFeO_x, maximizing Rh utilization and active sites availability. The unique raspberry-like morphology forms Rh-NiFeO_x interfaces, significantly enhancing catalytic performance compared to simple physical mixtures. The catalyst exhibits a substantially lower overpotential and a 17-fold higher noble metal mass activity, coupled with accelerated reaction kinetics and excellent long-term stability. Density functional theory (DFT) calculations reveal that the Rh-NiFeO_x interfaces facilitate the reaction between protons and adsorbed hydrogen intermediates, thereby boosting HER efficiency. This work provides a new approach for designing noble metal/oxide heterostructures with synergistic interfacial effects to enhance alkaline HER performance.