3D MoS2-rGO@Mo nanohybrids for enhanced hydrogen evolution: The importance of the synergy on the Volmer reaction

Abstract

Hydrogen evolution reaction (HER) through electrocatalytic water splitting is regarded as a promising route to produce hydrogen in a large scale. Molybdenum disulfide (MoS2) has been reported as a transition metal electrocatalysts, but generally with a poor activity, e.g. 540 mV overpotential at 10 mA cm−2 and Tafel slope value of 84 mV dec−1. A 3D MoS2-rGO@Mo nanohybrids, a three-dimensional MoS2 nanosheets network coated with reduced graphene oxide (rGO) on molybdenum mesh, is demonstrated as one of the best MoS2-based electrocatalysts. It delivers a benchmark current density of 10 mA cm−2 under a small overpotential (∼123 mV) with a low Tafel slope (∼62 mV dec−1), and an excellent stability performance. Its excellent performance can be attributed to the synergy between the 3D MoS2 and rGO with abundant active sites and high conductivity which leads to a faster water dissociation on the surface in the Volmer step.