Graphene Porous Foam Loaded with Molybdenum Carbide Nanoparticulate Electrocatalyst for Effective Hydrogen Generation

A facile method is developed for the synthesis of graphene porous foam (Gr PF) loaded with dispersed molybdenum carbide (Mo2C) nanoparticles; the material exhibits effective catalytic activity in the hydrogen evolution reaction (HER). Mo2C/Gr PF is synthesized by the carbonization of glucose and the carbothermal reduction of hexaammonium molybdate in a confined space defined by the intervals between sodium chloride nanoparticles. The synthesis in the confined space results in thin Gr PF (approximate to 8 nm) loaded with aggregation-free small Mo2C nanoparticles [(13 +/- 2) nm]. The overpotential required for a current density of 20 mA cm(-2) in the electrochemical hydrogen generation is as small as 199 mV in acidic solution and 380 mV in basic solution. The performance is superior to that of a Mo2C/C composite and compares favorably to those reported for Mo2C nanostructures. The Mo2C/Gr PF affords stable water electrolysis in both acidic and basic solution and exhibits nearly 100% faradaic efficiency. The prominent performance, long-term stability, and high faradic efficiency make Mo2C/Gr PF a promising HER catalyst for practical hydrogen generation from water electrolysis.