Alkaline glucose oxidation on nanostructured gold electrodes

The electrocatalytic properties of nanostructured gold electrodes for glucose electro-oxidation in KOH were investigated by cyclic voltammetry and compared with a commercially available polycrystalline gold electrode. These electrodes were prepared by depositing gold nanoparticles from a sol onto different carbonaceous conductive supports: glassy carbon, carbon cloth and graphite paper. The gold sol was prepared reducing an aqueous solution of tetrachloroauric acid with sodium borohydride. In order to improve gold nanoparticle adhesion, the substrate surfaces were treated with warm concentrated nitric acid. Gold on treated carbon cloth turned out to be a very promising anode for glucose electro-oxidation. In order to better understand the glucose oxidation its pH dependence as well as sorbitol (the glucose reduction product) electroxidation were investigated.