Mo3N2/VO2 composite as electrocatalysts for hydrogen evolution reaction

There is a clear need to develop efficient and stable electrocatalysts for hydrogen evolution reaction (HER) that do not rely on noble metals. Transition metal nitrides are emerging as good substitutes for HER electrocatalysts because of their distinctive electronic properties and availability. Furthermore, forming suitable heterojunctions can improve their activities further. Here, a nitridation treatment, followed by a solvothermal method is used to synthesize Mo 3 N 2 /VO 2 composites for obtaining outstanding HER electrocatalysts that operate in an acidic solution. The introduction of VO 2 enhances the electronic conductivity and the active sites of Mo 3 N 2 /VO 2 . More so, the synergy between the interface of Mo 3 N 2 and VO 2 facilitates electron transfer and speeds up reaction kinetics. When investigated for HER, the best Mo 3 N 2 /VO 2 catalyst displays remarkable catalytic activity with an overpotential of 166 mV and a rather small Tafel slope of 43 mV dec −1 in 0.5 M H 2 SO 4 at a current density of 10 mA cm −2 . As prepared Mo 3 N 2 /VO 2 exhibits excellent stability in acidic solution over 12 h. This work opens up the possibility associated with molybdenum nitride-based electrocatalysts.