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

摘要

Bromine (Br)-adatom (Br{sub}(ads)) was in situ fabricated onto polycrystalline gold (Au (poly)) electrode in Br{sub}--containing alkaline media. The surface coverage of Br{sub}(adS) (Г{sub}(Br) varied only in the submonolayer coverage within the investigated potential window under potentiodynamic condition because of the coadsorption of hydroxyl ion (OH{sup}-) in alkaline media. The in situ fabricated Br{sub}(ads)-submonolayer-coated Au (poly) electrode was successfully used for the electrochemical oxidation of hydrogen peroxide (H{sub}2O{sub}2). 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 H{sub}2O{sub}2 was explained based on the enhanced electrostatic attraction between the anionic HO{sub}2{sup}- molecules and Br{sub}(ads)-adlayer-induced positively polarized Au (poly) electrode surface.