Heterostructure engineering of Co-doped MoS2 coupled with Mo2CTx MXene for enhanced hydrogen evolution in alkaline media.

The hydrogen evolution reaction (HER) in alkaline media is key for the cathodic reaction of electrochemical water splitting, but it suffers sluggish kinetics due to the slow water dissociation process. Here, we present a simple strategy to enhance the HER activity in alkaline media by engineering Co-doped MoS2 coupled with Mo2CTx MXene. The improved HER activity might be ascribed to the synergistic regulation of water dissociation sites and electronic conductivity. Co doping could effectively regulate the electronic structure of MoS2 and further improve the intrinsic activity of the catalyst. Mo2CTx MXene served as both the active and conductive substrate to facilitate electron transfer. As a result, the Co-MoS2/Mo2CTx nanohybrids showed dramatically enhanced HER performance with a low overpotential of 112 mV at a current density of 10 mA cm-2 and exhibited excellent long-term stability in alkaline media.