Honeycomb-like MoCo alloy on 3D nitrogen-doped porous graphene for efficient hydrogen evolution reaction

An efficient electrocatalyst is indispensable to significantly reduce energy consumption and accelerate the conversion efficiency of water splitting. In this work, the honeycomb-like porous MoCo alloy on nitrogen-doped three-dimensional (3D) porous graphene substrate (Mo0.3Co0.7@NPG) has been synthesized from the annealing of layered double hydroxide (MoCo-LDH@NPG). Especially, the Mo0.3Co0.7@NPG exhibits low hydrogen evolution overpotential of 75 mV (10 mA.cm(-2)) and a Tafel slope of 69.9 mV.dec(-1), which can be attributed to highly conductive NPG substrate, the unique nanostructure and the synergistic effect of Mo and Co. Moreover, the Mo0.3Co0.7@NPG can maintain the original morphology and high catalytic activity after 50-h stability test. This work proposes a general strategy to synthesize a multi-element alloy on conductive substrates with high porosity for electrocatalytic reaction.

Automated summary

This study successfully synthesized a honeycomb-like porous MoCo alloy electrocatalyst on a nitrogen-doped three-dimensional porous graphene substrate, which exhibited low hydrogen evolution overpotential and high catalytic activity. Moreover, the electrocatalyst remained highly active after stability testing.