A unique adsorption-diffusion-decomposition mechanism for hydrogen evolution reaction towards high-efficiency Cr, Fe-modified CoP nanorod catalyst

The rational construction of high-efficiency transition metal phosphides catalysts for hydrogen evolution reaction (HER) is crucial since their sluggish kinetics of water dissociation remain severe barriers for HER performance. The theoretical calculations indicate a unique adsorption-diffusion-decomposition mechanism for H 2 O molecules on CoP (111) surface. Herein, Fe could decrease H 2 O decomposition barrier energies and increase the amount of active sites, along with Cr could accelerate H 2 O adsorption, diffusion and increase the conductivity of the reaction surface. Aided by this mechanism, a self-supported electrode of Cr and Fe dual-doped CoP nanorod arrays grown on nickel foam was prepared. The electrode only requires an overpotential of 27 mV at 10 mA cm −2 for alkaline HER with excellent durability for 400 h. Moreover, the catalyst presents only 1.505 V at 10 mA cm −2 for alkaline water electrolysis. This work provides an in-depth understanding on catalytic mechanism of CoP-based materials.