Hydrothermal Synthesis of TiO2/SrTiO3 Composite Nanostructures for Use in Photocatalysis

Increasing the photocatalytic activity of titanium dioxide TiO2 by forming composites with perovskite-type semiconductors is a pressing issue in semiconductor photocatalysis technology. To form similar structures with TiO2, strontium titanate SrTiO3 is used. The paper describes a method for obtaining TiO2/SrTiO3 composites formed by SrTiO3 nanocubes on the surface of filiform TiO2 in order to improve its photocatalytic activity. Nanocubic SrTiO3 obtained from strontium hydroxide octahydrate Sr(OH)2 ⋅ 8H2O and hydrogen titanate H2Ti3O7 in a two-stage hydrothermal reaction. A method is described for forming a TiO2/SrTiO3 composite layer on a titanium foil substrate for studying photocatalytic properties using gas chromatography. Results are presented of a study of the morphology of TiO2/SrTiO3 nanostructures by scanning electron microscopy and phase composition of samples by X-ray phase analysis depending on the synthesis temperature and post-processing temperature. Results are presented of measuring the optical band gap of the TiO2/SrTiO3 composite obtained by diffuse reflectance spectroscopy. Based on the yield values of the components, results of the study of the photocatalytic activity of samples in the reaction of carbon dioxide CO2 reduction are described. The results show that the overall yield of reaction products increased threefold using the TiO2/SrTiO3 composite compared to commercial titanium dioxide TiO2 P25.