3D Graphene Aerogels Decorated with Cobalt Phosphide Nanoparticles as Electrocatalysts for the Hydrogen Evolution Reaction.

The development of non-precious-metal hydrogen evolution reaction (HER) electrocatalysts with high activity and excellent durability in acidic media is of significant importance for renewable energy research. We report a novel electrocatalyst based on a three-dimensional (3D) graphene aerogel decorated with cobalt phosphide nanoparticles (CoP/GA). The material has a unique hierarchical porous structure with CoP nanoparticles encapsulated uniformly within the graphene sheets. The optimized catalyst shows superior activity, with an overpotential of only 121 mV at 10 mA cm-2 , a Tafel slope of 50 mV dec-1 , and an exchange current density of 0.105 mA cm-2 , and it maintains its catalytic activity for at least 13 h. More importantly, this work provides a versatile way for the rational design and fabrication of 3D graphene-based multifunctional composite materials.