UV-Induced Desorption-Retrapping Cycle of Electrochemically Adsorbed CO on Pt(111) Surface

UV irradiation (266 nm) from a nanosecond and/or a femtosecond laser-induced reconstruction of CO adsorbed layer on Pt(111) electrode. The current peak shape in the cyclic voltammogram (CV) for the electrochemical oxidation of the adsorbed CO was varied by the irradiation, which did not leave any change in the CV response on the adsorption free Pt(111) surface. Although the current peak shape in the CV was changed, the total charge for the CO oxidation remained constant. The green light irradiation (532 nm) from the lasers did not induce any change in the CV. These findings suggested that the UV induced CO desorption and re-trapping cycles were sustained on the electrode surface, which passed through electronic excited states at the surface.