Metal chalcogenides (CuS or MoS 2 )-modified TiO 2 as highly efficient bifunctional photocatalyst nanocomposites for green H 2 generation and dye degradation

Herein, we report the modification of TiO 2 nanostructures with two different metal chalcogenides (CuS or MoS 2 ). The effect of the preparation scheme (hydrothermal and coprecipitation methods) and the mass ratio of metal chalcogenides were investigated. The as-synthesized photocatalyst nanocomposites were fully characterized by various techniques. Moreover, the photo/electrochemical analysis were performed to investigate the photoelectric properties and photocatalytic mechanism. The photocatalytic performance was evaluated using two test reactions. In the case of H 2 generation via water splitting, it was found that 0.5 wt% CuS-TiO 2 synthesized via the coprecipitation method exhibited an initial hydrogen evolution rate (HER) of 2.95 mmol h −1 g −1 . While, the optimized 3 wt% MoS 2 -TiO 2 synthesized by the hydrothermal method, showed an HER of 1.7 mmol h −1 g −1 . Moreover, the degradation efficiency of methylene blue dye was 98% under UV–Vis light irradiation within 2 h over 0.5 CT_PP and 3MT_HT. Under visible irradiation, the degradation efficiency was 100% and 96% for 3MT_PP and 0.5CT_HT in the presence of H 2 O 2 , respectively. This study has proven that metal chalcogenides can act as effective, stable, and low-cost bifunctional co-catalysts to enhance the overall photocatalytic performance.