Facile microwave approach towards high performance MoS2/graphene nanocomposite for hydrogen evolution reaction

Low-cost, highly efficient catalysts for hydrogen evolution reaction (HER) are very important to advance energy economy based on clean hydrogen gas. Intensive studies on two-dimensional molybdenum disulfides (2D MoS2) have been conducted due to their remarkable catalytic properties. However, most of the reported syntheses are time consuming, complicated and less efficient. The present work demonstrates the production of MoS2/graphene catalyst via an ultra-fast (60 s) microwave-initiated approach. High specific surface area and conductivity of graphene delivers a favorable conductive network for the growth of MoS2 nanosheets, along with rapid charge transfer kinetics. As-produced MoS2/graphene nanocomposites exhibit superior electrocatalytic activity for the HER in acidic medium, with a low onset potential of 62 mV, high cathodic currents and a Tafel slope of 43.3 mV/decade. Beyond excellent catalytic activity, MoS2/graphene reveals long cycling stability with a very high cathodic current density of around 1000 mA cm−2 at an overpotential of 250 mV. Moreover, the MoS2/graphene-catalyst exhibits outstanding HER activities in a temperature range of 30 to 120°C with low activation energy of 36.51 kJ mol−1, providing the opportunity of practical scalable processing.