Bimetal Mo–Ni/NC as an effective electrocatalyst with accelerated kinetics for the oxygen evolution reaction

Abstract

Bimetal Mo–Ni/NC electrocatalysts have been successfully prepared via the carbonization of a N-rich Mo–Ni-metal organic framework (MOF) precursor. The samples were characterized using X-ray diffraction (XRD), laser micro-Raman spectrometry, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectrometry (XPS). Due to the increased number of catalytic active sites, good conductivity and stability of porous carbon, N-doped carbon and Mo–Ni bonds, the Mo-0.003-Ni/NC composite exhibits outstanding catalytic activity towards the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. The experimental results show that excellent HER activity with a low overpotential of 141 mV at 10 mA cm−2 and Tafel slope of 75.2 mV dec−1, as well as outstanding OER activity with an low overpotential of 270 mV at 10 mA cm−2 and a small Tafel slope of 64.3 mV dec−1 can be achieved by Mo-0.003-Ni-NC. The enhanced reaction kinetics may be attributed to the reconstruction of hierarchical Mo-0.003-Ni-NC micro-/nanoarchitectures. This work may provide a feasible method to design efficient and stable electrocatalysts for application in the renewable energy field.