Direct Z-scheme of Cu 2 O/TiO 2 enhanced self-cleaning, antibacterial activity, and UV protection of cotton fiber under sunlight

Abstract

This work presents a modified solvothermal process for a facile synthesis of high thermally stable nanocrystalline anatase TiO 2 NPs doped with Cu 2 O NPs. A Z-scheme mechanism was used to account for the enhanced photocatalytic activity exhibited by these materials. Also, the nanocomposite was impregnated in cotton fabric to obtain a modified fiber with high thermal stability, self-cleaning, enhanced UV protection, and antibacterial activity. The as-prepared nanomaterials and the coated fabric were characterized by various physicochemical techniques such as XRD, EDXRF, TGA, TEM, HRTEM, and SEM. The Cu 2 O/TiO 2 molar ratio in the nanocomposite was found to possess a pronounced impact on the crystalline structure, size and morphology of TiO 2 NPs. The XRD revealed proper substitutions of the few Ti 4+ sites by Cu 2+ ions in TiO 2 host lattice. Optical measurements showed that the plasmonic peak of the Cu 2 O/TiO 2 nanocomposite was affected by the copper-doping concentration, enhancing self-cleaning of Cu 2 O/TiO 2 under direct sunlight. The TiO 2 /fiber self-cleaning efficiency (12 h for MB removal) was increased by the in situ growing of Cu 2 O (5.5 h). Antibacterial activity studies revealed high potential activity of Cu 2 O/TiO 2 against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Kleissella pneumonia, Saccharomyces sp.) bacteria. The promising photocatalytic and biocidal activity of our synthesized Cu 2 O/TiO 2 nanocomposites was ascribed to the reactive oxygen species generated by the Z-scheme mechanism under direct Sunlight.