Fabrication and photoelectrochemical properties of La5Ti2MS5O7 (M = Ag, Cu) electrodes

Electrodes of La5Ti2MS5O7 (M = Ag, Cu) were prepared and photoelectrochemical properties of the electrodes were investigated. Two types of electrode preparation methods were carried out: one was spreading a viscous slurry of the bulk powder on a glass plate coated with fluorine-doped tin oxide, and another was thin film growth by vacuum processes followed by annealing treatment. By the use of vacuum processes, clear and higher photocurrent under visible-light irradiation was observed for both La5Ti2CuS5O7 and La5Ti2AgS5O7. The observed photocurrent was photocathodic, indicating that these materials acted as a p-type semiconductor. La5Ti2MS5O7 are promising materials of a photoelectrode for water splitting under visible-light irradiation.