Influence of lanthanum-doping on the Photochemical properties of SrTiO3 polycrystalline anodes

A series of Sr1−xLaxTiO3 (0 < x < 0.015) ceramics were prepared and evaluated as semiconducting anodes in the photoassisted electrolysis of water. We report on subband-gap photoresponse for La-doped samples due to electron transfer via deep donor and acceptor intraband-gap centers associated with structural defects. A tailing of the band-gap absorption due to energy states near the band edges gives rise to an increase of the flat-band potential and a decrease of the optical band-gap.