CHEMICAL MODIFICATION OF GAPC-CL THIN-FILM PHOTOELECTRODES

Modification of chlorogallium phthalocyanine (GaPC-Cl) thin film photoelectrodes with thin films of polyvinylferrocene (PVF), thin films of PVF with incorporated ferricyanide, and thin films of a coprecipitated ferricenium-ferricyanide salt is demonstrated. The analysis of the coprecipitated ferricenium-ferriccanide salt demonstrates the formation of a Prussian Blue (PB)-like electroactive film. PVF films on bare gold were first characterized to demonstrate incorporation of ferricyanide during formation of ferricenium ions. This was followed by demonstration of the direct interaction of ferrocenium and ferricyanide, without the polymer, on bare gold, and on the Pc surface. GaPc-Cl films overlayed with PB thin films formed from ferricenium/ferricyanide can produce either negative or positive photopotentials, depending upon the dopant condition of the Pc layer, relying only upon the photoelectrochemical redox activity of the PB layer.