P-doped MOF-derived NiMo bimetallic sulfide used as a high efficiency electrocatalyst for oxygen evolution reaction.

Metal-organic frameworks (MOF) were used as templates to prepare transition metal sulfides and phosphides in order to expose the active site of the material to a greater extent. Utilizing the synergistic effect of bimetals, Ni²⁺ and Mo⁶⁺ were selected as metal ion centers and trimesic acid was selected as the ligand to prepare NiMo-MOFs by the hydrothermal method. Then, NiMo-P, NiMo-S and NiMo-P/S were prepared using NiMo-MOFs as the precursor, and the preparation conditions of the abovementioned hybrids were optimized through linear sweep voltammetry. The results show that when the molar ratio of NiMo-MOF to NaH₂PO₂ is 1: 5, and the as-prepared NiMo-P is further doped with S in a proportion of 1: 1, the overpotential of the final NiMo-P/S hybrid is 313 mV at a current density of 10 mA cm^-2, and its electrochemical impedance (Rct), Tafel slope and electrochemical active surface areas are 22.38 Ω, 63.8 mV dec^-1, and 707.5 cm^-2, respectively. The optimized NiMo-P/S hybrid provides more active sites and reaction areas along with good stability, which is conducive to promoting the kinetics of the oxygen evolution reaction. [ABSTRACT FROM AUTHOR]