The controllable synthesis of porous MoN nanorods/carbon for highly efficient electrochemical hydrogen evolution

Abstract

MoN is a promising material for electrochemical hydrogen evolution due to its cheap price and excellent catalytic activity sites, but the low conductivity prevents further improvement of its catalytic performance. In this work, porous MoN nanorods have been fabricated with an efficient and facile precursor method. XRD, Raman and TEM showed MoN nanorods with diameters of about 100 nm. With a simple mechanical mixing method, MoN/conductive carbon black (CB) composites with different weight ratios have been fabricated. The composite possessed two merits, that is, the more catalytic active site in MoN nanorods due to the porous structure, and fast electron transfer due to the CB. So, it has been used as a hydrogen evolution material. With the proper weight ratio, the composite exhibited brilliant catalytic activity and durability in acidic media. It possesses an overpotential of 162 mV to approach 10 mA cm⁻², a small Tefel slope of 54 mV dec⁻¹ and maintains the good electrocatalytic activity for at least 10 h. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that the electrocatalyst possessed a high catalytic active area and fast electron transfer. These results can compare with many other recently reported nitride catalysts. Our work possibly provides a new avenue for the preparation of a MoN-based catalyst for highly efficient electrochemical hydrogen evolution.