Photocharge-Discharge Behaviors of Hybrid WO[sub 3]∕TiO[sub 2] Film Electrodes

Abstract

Photoelectrochemical energy conversion and electron storage were investigated on hybrid W O3 Ti O2 film electrodes. Photoexcitation of W O3 Ti O2 was observed to undergo charge accumulation, i.e., double injection of electrons and protons into W O3 to form tungsten bronze by the oxidation of oxalic acid or methanol to form C O2. It was clearly indicated that hybrid W O3 Ti O2 involving highly dispersed W O3 (an amorphous-like W O3 phase) exhibits more effective reversibility for photocharge-discharge processes than a hybrid involving a bulk polycrystalline W O3. The energy band structure and phase changes of W O3 into tungsten bronze (H0.23 W O3 and H0.33 W O3) by photocharge or electrocharge of the hybrid W O3 Ti O2 have also been characterized. © 2006 The Electrochemical Society.