Electronic modulation by N incorporation boosts the electrocatalytic performance of urchin-like Ni5P4 hollow microspheres for hydrogen evolution

The exploitation of economical, efficient and durable electrocatalysts toward the hydrogen evolution reaction (HER) is of far-reaching significance for the scalable implementation of the water electrolysis technology and associated sustainable energy devices. The rational design of high-efficiency HER catalysts requires the overall consideration of both thermodynamic and kinetic aspects. Herein, we demonstrated a feasible synthesis of urchin-like N-doped Ni5P4 hollow spheres, which simultaneously integrate electronic regulation through anion-doping with rich active sites through nanostructuring. Systematic experiments and density functional theory (DFT) calculations revealed the incorporation of N into Ni5P4 lattice could dramatically enrich the number of active sites and modulate the electronic configuration for optimizing the hydrogen adsorption free energy. Due to the compositional and morphological superiorities, the N-Ni5P4 hollow spheres exhibited superior HER activity with a low overpotential of 96 mV at 10 mA cm(-2 )and remarkable durability in alkaline medium, holding a great promise for practical water-splitting applications.