Mechanistic insights into the enhanced photocatalytic performance of a TiO2-In2S3 heterojunction for efficient Rhodamine B degradation

The growing global concern over water pollution has amplified the demand for advanced, sustainable water treatment technologies. Photocatalysis offers a promising solution for effectively removing toxic organic contaminants, such as Rhodamine B (RhB), without generating secondary pollutants. However, despite the widespread use of TiO 2 -In 2 S 3 heterojunctions as photocatalysts to overcome the limitations of TiO 2 , the mechanisms behind their enhanced performance still need to be explored. In this study, a TiO 2 -In 2 S 3 photocatalyst with a heterojunction was constructed, and its enhanced photocatalytic performance was demonstrated by 90.6% degradation of RhB within 30 min, with a degradation rate constant 6.01 times that of pure TiO 2 and 4.89 times that of In 2 S 3 . Mechanistic investigations, including density functional theory calculations, revealed that hydroxyl radicals were the primary active species in the degradation process. Moreover, the TiO 2 -In 2 S 3 heterojunction enhanced the adsorption and stabilization of reaction intermediates, optimizing both reaction kinetics and selectivity. These findings highlight the potential of TiO 2 -In 2 S 3 heterojunctions as highly efficient photocatalysts for environmental remediation.