Metallic MoO layer promoting high-valence Mo doping into CoP nanowires with ultrahigh activity for hydrogen evolution at 2000 mA cm-2

High-valence metals such as Mo, W, etc. can modulate the adsorption and desorption energy of 3d-metal-based electrocatalysts, favorable for the intrinsic activity for hydrogen evolution reaction (HER) at large current density. However, the facile and exact incorporation of high-valence metals remains a big challenge. Herein, a metallic MoOx layer has been designed via anodization of Mo foil to achieve high-valence Mo doping into CoP to finally form the real active component Mo-CoP for HER. The activated metallic MoOx layer provides an optimized Mo doping into CoP, obtaining Mo-CoP/MoOx with ~226 mV (alkaline) and ~275 mV (acidic) at > 2000 mA cm-2. Meanwhile, in-situ grown F-Mo-CoP/MoOx controllable treated by fluoroaniline possesses enhanced the structural robustness of Mo-CoP/MoOx with long-term stability at large current density. This work not only illustrates the facile approach of regulating electron structure via high-valence metal doping, but it also provides the rational strategy for enhanced stability for industrial applications.