PHOTOELECTROCHEMICAL PROPERTIES OF TIO2 COATING FILMS PREPARED USING DIFFERENT SOLVENTS BY THE SOL-GEL METHOD

The effects of the solvent used for preparing a coating solution on th e photoelectrochemical properties of the sol-gel derived TiO2 film ele ctrodes have been investigated. Three series of TiO2 film electrodes w ere prepared from three different coating solutions, in which ethanol, ethanol-isopropyl alcohol and ethanol-2-ethoxyethanol were used as a solvent, and Ti (OC3H7i)(4) as a source of TiO2. The photocurrent of e ach series of TiO2 film electrodes increased with increasing film thic kness up to about 1 mu m and became almost invariant beyond that, indi cating that a film thickness of about 1 mu m is required for achieving the highest efficiency. The photoelectrochemical performance of TiO2 film electrodes was strongly dependent on the heat-treatment condition s as well as on the composition of the starting solutions. The results obtained were mainly explained in terms of the electrical resistance of the TiO2 film electrodes.