Titanium-oxo-clusters precursors for preparation of In2S3/TiO2 heterostructure and its photocatalytic degradation of tetracycline in water

In this work, In2S3/TiO2 composites were successfully synthesized by hydrothermal method and used to degrade tetracycline (TC) in water effectively under visible light. Preformed solid state Titanium-oxo-clusters were used as TiO2 sources to avoid the spontaneous hydrolysis and condensation reactions of traditional titanium sources. Compared with the direct addition of TiO2, the nucleation of TiO2 can be controlled in hydrothermal process dependent on the solubility of Titanium-oxo-clusters in water, leading to formation of homogeneous heterostructure of TiO2 and In2S3. The as-prepared In2S3/TiO2 composite achieved the better performance of photodegradation TC than that of pure TiO2 and In2S3. Meanwhile, the mole ratio of In and Ti was 0.34:1 among In2S3/TiO2 composite displayed the best photocatalytic activity, which the efficiency for degrade TC (40 ​mg/L) reached 78.1% within 60 ​min higher than 54.6% of In2S3/TiO2 composite prepared by commercial TiO2 powders. Furthermore, the capture experiments showed that the holes and superoxide radical were the main active substances in photocatalytic reactions, which elucidated the photocatalytic mechanism of In2S3/TiO2 heterostructure. The exploration in this work can boost new insight for the development of TiO2 based catalysts and provide a new raw material and a facile synthetic method for the large-scale production of TiO2 based composite materials.