Sensitization of Polycrystalline SrTiO3 Photoanodes by Lanthanum Doping

The behaviors of polycrystalline LaxSr1−xTiO3(x≤0.05) electrodes in a photoelectrochemical cell for water decomposition have been investigated in aqueous NaOH electrolyte. The lanthanum substitution for strontium resulted in impressive visible photosensitization of the corresponding electrodes under anodic polarization. This visible photoresponse is based on the relatively deep subband gap states introduced into the forbidden band by lanthanum doping, in analogy with the polished undoped SrTiO3 electrodes reported previously.