Electrocatalytic evolution of hydrogen on porous alumina/gelcast-derived nano-carbon network composite electrode

We presented a way to fabricate new porous alumina/gelcast-derived nano-carbon network (NCN) composite electrode using gelcasting and reduction-sintering method. The morphology, crystalline phases, and nanostructure of the alumina/NCN electrode were characterized. The electrocatalytic activity of this elelctrode toward hydrogen evolution reaction (HER) in alkaline solutions was investigated. The electrocatalytic activity analyzed by cyclic voltammetry exhibited the onset potential for HER shifted in the positive direction favoring hydrogen generation with lower overpotential on the porous electrode, compared with pure carbon electrode. This behavior was attributed to the high porosity and electrochemical surface area as well as the nanostructure of the electrode that was pyrolyzed nano-carbon networks introduced into the alumina ceramic matrix, which can greatly enhance the electrode electrocatalytic activity toward HER. The associated kinetic parameters of HER were systematically investigated using electrochemical impedance spectroscopy.