Plasma-Engineered MoP with nitrogen doping: Electron localization toward efficient alkaline hydrogen evolution

Surface engineering boosts electrocatalytic hydrogen evolution reaction (HER), and more importantly serves as a key platform to uncover catalytic mechanism. Herein, we use plasma treatment under N2 or Ar to engineer MoP for alkaline HER. Beyond the reduced particle size (in both Ar and N2 cases), the N2 plasma treatment further results in N-doping into MoP, which enriches Mo-P active species and causes electron localization near doped sites. Accordingly, water dissociation is promoted thanks to the facilitated OH* desorption, leading to remarkable improvement in alkaline HER. The optimal N-doped MoP accomplishes high performance in 1.0 M KOH, with a low η10 (overpotential at a current density of -10 mA cmgeo−2) of 70 mV and a low Tafel slope of 55 mV dec-1, which is superior to most of Pt-free counterparts. Providing atomic-level insight into the structure-activity relationship on engineered surface, this work will open up new opportunities for electrocatalyst design.