Harnessing the synergistic potential of TiO 2 -CuSe composites for enhanced photocatalytic and antibacterial activities.

With growing environmental concerns, the removal of toxic industrial dyes from wastewater has become a critical global issue. In this study, TiO 2 -CuSe composites were synthesized using a cost-effective and simple chemical method to determine the optimal concentration of CuSe for the efficient degradation of methylene blue (MB) under visible light. The TiO 2 samples exhibited a mix of rutile and anatase phases, while CuSe formed in a hexagonal phase. Both TiO 2 and CuSe were observed to have agglomerated particles with indistinct boundaries. The optical bandgap shifted towards the visible region from 3.25 eV (pure TiO 2 ) to 2.91 eV with increasing the amount of CuSe in the composites. The photocatalytic activity of TiO 2 , CuSe, and TiO 2 -CuSe composites was evaluated by monitoring MB degradation, with the composites outperforming the individual components under visible light. Notably, the TiO 2 -20% CuSe composite (AK-4) demonstrated superior efficiency, removing 98% of MB in just 70 minutes. The photocatalysts also exhibited enhanced antibacterial properties, effectively reducing E. coli colonies from 1.71 × 10 12 CFU mL -1 (pure TiO 2 ) to 1 × 10 10 CFU mL -1 for the AK-4 composite. This study suggests that visible light-activated TiO 2 -CuSe composites could be effective for both water purification and bacterial infection control.