Novel synthesis and photocatalytic activity of oxysulfide Sm2Ti2S2O5

The oxysulfide Sm2Ti2S2O5 was synthesized by, sulfurization Of Sm2Ti2O7 under H2S flow. Amorphous Sm2Ti2O7 was found to be the most appropriate precursor for the synthesis of Sm2Ti2S2O5 at temperatures above 1073 K. The relationship between the preparation conditions and the photocatalytic activities for H+ reduction to H-2 and H2O oxidation to O-2 was investigated, and the highest activities for both H-2 and O-2 evolution were obtained at a sulfurization temperature of 1123 K. Subsequent heating Of Sm2Ti2S2O5 in air enhanced the activities further. Sulfurization by H2S allows for synthesis Of Sm2Ti2S2O5 at lower temperatures with a significantly shorter heating period (1 h) than that of conventional solid-state reaction.