Photoelectrocatalytic reactions of metal complexes at chemically modified electrodes

摘要

One of the outstanding properties of the ion-exchange membranes is their multiphase structure with microheterogeneous environment. Recently we have shown that ion-exchange membranes such as Nation and clay can be effectively used in preparing chemically modified electrodes with adsorbed photoactive and electroactive molecules. A new photogalvanic cell was constructed by coating one electrode with Nafion-[Ru(bpy)_3]~(2+) and the other with clay-[Ru(bpy)_3]~(2+). This new photogalvanic cell showed an additive photogalvanic response on visible light irradiation. The quenching rate constants, k_q for the reaction of excited state [Ru(bpy)_3]~(2+) adsorbed into the membrane with Fe~(3+) ion and cobalt(III) complexes were determined by photoelectrochemical methods. The photo-electrocatalytic reduction of oxygen to hydrogen peroxide at chemically modified electrodes was carried out by using [Ru(bpy)_3]~(2+) as sensitizer and macrocyclic cobalt(III) complexes as electron relay.