Defect Engineering of Photocatalysts by Doping of Aliovalent Metal Cations for Efficient Water Splitting

Doping of aliovalent metal cations to SrTiO3, a photocatalyst for overall water splitting, was variously examined for the control of defect structure as well as the photocatalysis. Doping of a cation with valence lower than that of the parent cation effectively enhanced photocatalytic activity, while the doping of a higher valence cation led to the suppressed photocatalysis. It was demonstrated that the doping of a lower valence cation to intentionally introduce oxygen vacancies and decrease Ti3+ is effective to enhance photocatalytic activity.