Harnessing the synergistic potential of TiO2–CuSe composites for enhanced photocatalytic and antibacterial activities

Abstract

With growing environmental concerns, the removal of toxic industrial dyes from wastewater has become a critical global issue. In this study, TiO₂–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 TiO₂ samples exhibited a mix of rutile and anatase phases, while CuSe formed in a hexagonal phase. Both TiO₂ and CuSe were observed to have agglomerated particles with indistinct boundaries. The optical bandgap shifted towards the visible region from 3.25 eV (pure TiO₂) to 2.91 eV with increasing the amount of CuSe in the composites. The photocatalytic activity of TiO₂, CuSe, and TiO₂–CuSe composites was evaluated by monitoring MB degradation, with the composites outperforming the individual components under visible light. Notably, the TiO₂–20% 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 × 10¹² CFU mL⁻¹ (pure TiO₂) to 1 × 10¹⁰ CFU mL⁻¹ for the AK-4 composite. This study suggests that visible light-activated TiO₂–CuSe composites could be effective for both water purification and bacterial infection control.