AgNi@ZnO nanorods grown on graphene as an anodic catalyst for direct glucose fuel cells

Nano carbon-semiconductor hybrid materials such as graphene and zinc oxide (ZnO) have been vigorously explored for their direct electron transfer properties and high specific surface areas. We fabricated a three-dimensional anodic electrode catalyst nanostructure for a direct glucose fuel cell (DGFC) utilizing two-dimensional monolayer graphene and one-dimensional ZnO nanorods, which accommodate silver/nickel (Ag/Ni) nanoparticle catalyst. Glucose, as an unlimited and safe natural energy resource, has become the most popular fuel for energy storage. Ag and Ni nanoparticles, having superior catalytic activities and anti-poisoning effect, respectively, demonstrate a 73-times enhanced cell performance (550 µW cm⁻² or 8 mW mg⁻¹) when deposited on zinc oxide nanorods with a small amount of ∼0.069 mg in 0.5 M of glucose and 1 M of KOH solution at 60 ^oC. This three-dimensional anodic electrode catalyst nanostructure presents promise to open up a new generation of fuel cells with non-Pt, low mass loading of catalyst, and 3D nanostructure electrodes for high electrochemical performances.