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 N-2 or Ar to engineer MoP for alkaline HER. Beyond the reduced particle size (in both Ar and N-2 cases), the NZ 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 eta(10) (overpotential at a current density of -10 mA cm(geo)(-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.