Synergistic effect of Co3Mo3C and Co in N-doped carbon for efficient overall water splitting

Highlights: : • The Co₃Mo₃C/Co@NC composite shows excellent electrocatalytic performance, with the lower overpotential of 68 mV and 340 mV at a current density of 10 mA cm⁻² for HER and OER, respectively. • The synergistic effect between Co₃Mo₃C and Co nanoparticles enhanced the Co₃Mo₃C/Co@NC electrocatalytic performance. • N-doped carbon provide efficient electron transfer pathways, increasing the number of active sites. -- Abstract: The design of highly efficient electrocatalysts with low cost is remarkable to lower the overpotentials and energy consumption. Multi-metal-based electrocatalysts have attracted widespread attention because of their prominent electrical conductivity and synergistic catalysis effects between metal atoms. Herein, we design novel electrocatalysts consisting of Co₃Mo₃C/Co nanoparticles anchored in N-doped carbon (Co₃Mo₃C/Co@NC) via pyrolysis of cobalt molybdenum alkoxide and dicyandiamide. On account of the synergistic effect between Co₃Mo₃C and metallic Co, the composite enriches high activity and fast kinetics. Furthermore, nitrogen-doped carbon skeleton facilitates better corrosion resistance, high conductivity as well as fast electron transfer. The resulting Co₃Mo₃C/Co@NC composite electrode shows outstanding performance with a lower overpotential of 68 mV and 340 mV at a current density of 10 mA cm⁻² for HER and OER, respectively. The influence of Co on the activity of electrode materials and related mechanisms investigate systematically, which will open new perspectives to further design low cost functional materials for efficient water splitting.