HIGHLY EFFICIENT SEMICONDUCTING TIO2 PHOTOELECTRODES PREPARED BY AEROSOL PYROLYSIS

TiO2 layers were prepared on F-doped SnO2 supports by pyrolysis of eth anolic solution of di-iso-propoxy titanium-bis(acetylacetone) in aeros ol form. By optimization of preparation conditions, the incident photo n-to-current conversion efficiency of water oxidation on these electro des is typically 75-80% at lambda = 300-330 nm. Comparison of optical and photoelectrochemical properties of the TiO2 layer indicates a rela tive enhancement of light harvesting efficiency due to lowering of ref lection losses in the electrolyte. The flatband potential measured by electrochemical impedance is well comparable with the potential at whi ch the formation of the accumulation layer is detected spectroelectroc hemically. Doping with Fe and Nb decreases the photocurrent efficienci es, in the first case dramatically