Defect engineering with N-doped carbon hybrid cobalt-molybdenum phosphide nanosheets wrapped molybdenum oxide...

Regulating the electrocatalytic hydrogen evolution reaction (HER) performance through defect engineering of the surface of the catalysts is an effective pathway. Herein, cobalt-molybdenum phosphide (CoMoP) nanosheets wrapped molybdenum oxide (MoO₃) core-shell nanorods (MoO₃@CoMoP), as alkaline electrocatalysts with ligand-derived N-doped carbon hybrid and oxygen-vacancies, were synthesized via solvothermal approaches and followed by phosphorization. As expected, the MoO₃@MoCoP affords efficient HER with a low overpotential (η) of 84.2 ± 0.4 mV at 10 mA cm^-2. After phosphorization, not only the MoCoP active species are incorporated into the catalyst, but also the defects sites are achieved. Impressively, the metal-ligand-derived MoCoP are distributed uniformly in the N-doped carbon hybrid matrix, exhibiting well-exposed active sites. Benefiting from the synergy effect of MoCoP active species and oxygen-vacancy, the MoO₃@MoCoP showed increased conductivity and stability, which can deliver a current density of 10 mA cm^-2 over 40 h. MoO₃@MoCoP exhibits an optimal electronic structure on the surface by charge redistribution at the interface, thereby optimizing the hydrogen adsorption energy and accelerating the hydrogen evolution kinetics. This work paves the way for the design of transition metal electrocatalysts with desirable properties through a promising strategy in the field of energy conversion.