Electrochemical oxidation of hydrogen peroxide at a bromine adatom-modified gold electrode in alkaline media

Bromine (Br)-adatom (Br(ads)) was in situ fabricated onto polycrystalline gold (Au (poly)) electrode in Br−-containing alkaline media. The surface coverage of Br(ads) (ΓBr) varied only in the submonolayer coverage within the investigated potential window under potentiodynamic condition because of the coadsorption of hydroxyl ion (OH−) in alkaline media. The in situ fabricated Br(ads)-submonolayer-coated Au (poly) electrode was successfully used for the electrochemical oxidation of hydrogen peroxide (H2O2). About five times higher oxidation current was achieved at the modified electrode as compared with the bare electrode. The enhancement of the electrode activity towards the electrochemical oxidation of H2O2 was explained based on the enhanced electrostatic attraction between the anionic HO2− molecules and Br(ads)-adlayer-induced positively polarized Au (poly) electrode surface.