Synthesis of novel p-n heterojunction Cu2SnS3/Ti3+-TiO2 for the complete tetracycline degradation in few minutes and photocatalytic activity under simulated solar irradiation

Abstract

In this research work, p-n heterojunction Cu2SnS3/Ti3+-TiO2 photocatalysts were synthesized by using a facile hydrothermal method to degrade tetracycline and produce hydrogen energy. The properties of Cu2SnS3/Ti3+-TiO2 was analyzed by using XRD, SEM, TEM, HRTEM, BET, PL and UV–vis characterization. The HPLC-MS and TOC analyzer systems were used to analyze the intermediate products during the photocatalysis deprivation and total organic carbon. The characterizations showed that the addition of self-doped Ti3+ and Cu2SnS3 into TiO2 enhanced the material's crystallinity, increased the absorption region from 450 nm to 750 nm, increased the surface area of the material from 234 to 583 m2/g and reduced the recombination of charge carriers. Under visible light irradiation, Cu2SnS3/Ti3+-TiO2 exhibited excellent degradation performance and stability. The increase in the efficiency of the material is due to the creation of an internal electric field induced by the p-n heterojunction and reduction in the bandgap of the material, which efficiently reduced the rate of recombination, increased the surface area for light absorption and increased the transfer of charge carriers. The Cu2SnS3/Ti3+-TiO2 photocatalyst degraded 100 % tetracycline and produced 510 μmol/hg hydrogen energy. The Cu2SnS3/Ti3+-TiO2 composite exhibited good stability even after six cycles Cu2SnS3/Ti3+-TiO2 degraded 98–99 % TC under visible light irridiation. The efficiency of Cu2SnS3/Ti3+-TiO2 was also analyzed in the outdoor environment, confirming that this material can be effectively used in practical applications.