Electroswitchable Photoelectrochemistry by Cu2+−Polyacrylic Acid/CdS-Nanoparticle Assemblies

• Published in: The journal of physical chemistry. B Vol. 108; no. 1; pp. 11 - 15
• Main Authors: Sheeney-Haj-Ichia, Laila, Cheglakov, Zoya, Willner, Itamar
• Format: Journal Article
• Language: English
• Published: American Chemical Society 08-01-2004
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp0364295

CdS nanoparticles are incorporated into a poly(acrylic acid) (PAA) film associated with an Au electrode, and the nanoparticles are covalently linked to the matrix. Cu2+ ions are incorporated into the CdS-nanoparticle−PAA film, and the electroswitchable photocurrent generation by the system, in the presence of triethanolamine as sacrificial electron donor, is demonstrated. The electrochemical reduction of the CdS−Cu2+−PAA state to the CdS−Cu0−PAA state (−0.55 V vs SCE) leads to the formation of conductive metal nanoclusters that facilitate electron transfer of the CdS-conduction-band electrons to the electrode, and the generation of the photocurrent. The oxidation of the Cu0 clusters to Cu2+ ions linked to the carboxylate units of PAA (applied potential +0.55 V vs SCE) switches off the photocurrent. The system not only is active for the reversible electroswitchable photocurrent generation but also acts as a photoelectrochemical detector of Cu2+ ions.