Ni and N co-doped MoCx as efficient electrocatalysts for hydrogen evolution reaction at all-pH values

Abstract

To achieve sustainable production of H2 fuel through water splitting, noble-metal-free catalysts have been extensively studied for hydrogen evolution reaction (HER), especially molybdenum-based catalysts. Herein, we report the Ni, N-codoped MoCx (Ni–N–MoCx) nanoparticles synthesized from NiMoO4 precursor by oily-solvent-assisted strategy, following the calcination with dicyandiamide. As-obtained Ni–N–MoCx in different magnified SEM images shows grainy structure, MoCx nanoparticles uniformly disperse in carbon substrate. The obtained electrocatalysts can also efficiently electrocatalytic HER in a wide pH value. Ni–N–MoCx shows an onset potential of −74 mV, an overpotential of 163 mV to reach a current density of 10 mA/cm2 in acid media, an onset potential of −37 mV and overpotential of 124 mV to reach 10 mA/cm2 in alkaline media. The present study provides some guidelines for preparing the uniformly doped electrocatalysts from multiple compounds with devolatilization characteristics.