Clay-modified electrodes (CME) were made by binding Al13O4(OH)283+-pillared montmorillonite to SnO2and Pt surfaces via a thin (2-4 monolayer thick) coating of polymerized silane I. The polymer provides a binding site for multiply charged anions [formula-omitted] such as Fe(CN)64-and Mo(CN)84-, while the clay external surface strongly binds large cations such as Os(bpy)32+and Ru(bpy)32+. Charge-trapping behavior, which is a consequence of spatial ordering of the electroactive anions and cations, is observed in cyclic voltammetry of the CME in aqueous KH 2PO4solution. With Ru(bpy)32+exchanged onto the clay surface, photocathodic currents are generated with a quantum efficiency (per photon absorbed) of ca. 1%. This photocurrent is attributed to electron donor quenching of the Ru(bpy)32+excited state by Fe(CN)64-or Mo(CN)84-.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Inorganic Chemistry