S-Doped MoP Nanoporous Layer Toward High-Efficiency Hydrogen Evolution in pH-Universal Electrolyte

In this study, we report a nonprecious metal catalyst for high-efficiency hydrogen evolution reaction (HER). A self-organized S-doped MoP nanoporous layer (S-MoP NPL) is achieved through a facile electrochemical anodic process and a two-step chemical vapor deposition treatment, which was directly used as a binder-free catalyst for HER in pH-universal electrolytes. S-MoP NPL exhibits HER behavior with a low overpotential of 86 mV at 10 mA cm–1 and low Tafel slope of 34 mV dec–1 in acidic solution. Moreover, S-MoP NPL also shows high HER activity in basic and neutral electrolytes. Density functional theory (DFT) computations were carried out to support our experiment. The calculations show that the H2 formation (via Volmer–Heyrovsky mechanism) from the reaction of a metal (Mo) absorbed hydride with a solvated proton is favored over S-MoP than MoS2. Both experimental and computational studies demonstrate that the extraordinary HER activity and stability performance displayed by a MoP catalyst can be enhanced by S-doping, opening up a promising paradigm for the conscious design of high-performance nonprecious metal catalyst for hydrogen generation.