Synthesis and Characterization of Se4+@TiO2/PET Composite Photocatalysts with Enhanced Photocatalytic Activity by Simulated Solar Irradiation and Antibacterial Properties

To fabricate recyclable catalytic materials with high catalytic activity, Se⁴⁺@TiO₂ photocatalytic materials were synthesized by the sol-gel method. By introducing free radicals on the surface of polyester (PET) fabrics through plasma technology, Se⁴⁺@TiO₂/PET composite photocatalytic materials with high photocatalytic activity were prepared. The surface morphology, crystal structure, chemical composition, and photocatalytic performance were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible absorption spectroscopy (UV-Vis), and photoluminescence spectroscopy (PL), respectively. The photocatalytic degradation performance was determined by assessing the degradation of azo dye methyl orange under simulated solar irradiation. The results demonstrated that Se⁴⁺@TiO₂/PET exhibited a superior degradation rate of methyl orange, reaching up to 81% under simulated sunlight. The PL spectra indicated that the electron-hole pair separation rate of Se⁴⁺@TiO₂/PET was higher than that of TiO₂/PET. Furthermore, UV-Vis spectroscopy demonstrated that the relative forbidden band gap of Se⁴⁺@TiO₂/PET was determined to be 2.9 eV. The band gap of Se⁴⁺@TiO₂/PET was narrower, and the absorption threshold shifted toward the visible region, indicating a possible increase in its catalytic activity in simulated solar irradiation. In addition, the antibacterial properties of Se⁴⁺@TiO₂/PET were subsequently investigated, achieving 99.99% and 98.47% inhibition against <i>S. aureus</i> and <i>E. coli</i>, respectively.