Hot-Pressed Reinforced Photocatalyzed TiO₂/Chitosan/SiO₂ Nanofibers

This study introduces a novel fabrication method for high-strength, self-cleaning photocatalytic membranes through the integration of hot-pressing and TiO₂/chitosan/SiO₂ nanofibers. The innovation of this research lies in the hot-pressing technique, which significantly enhances the mechanical properties and photocatalytic efficiency by improving the adhesion, dispersion, and uniformity of the TiO₂/chitosan coating on SiO₂ nanofibers. SiO₂ nanofibers with an initial diameter of 0.79 ± 0.29 μm were coated and hot-pressed, resulting in a final diameter of 1.07 ± 0.57 μm, which corresponds to an approximate increase of 35.4%. In addition, the 1 wt% TiO₂-CTS sample showed the highest adhesion and surface energy, with values of 0.1 nN/nm², indicating the closest intermolecular binding. 3 wt% SiO₂-CTS exhibits a maximum hardness of 5.23 Pa. The 3 wt% TiO₂-chitosan coating demonstrated outstanding mechanical performance, achieving a fracture stress of 0.53 MPa, approximately five times that of the untreated SiO₂ nanofibers, a Young's modulus of 0.63 MPa, and a toughness to triple of 0.27 MJ/m³-representing substantial improvements over uncoated membranes. Photocatalytic efficiency was significantly enhanced, with grayscale values increasing approximately 36% UV light exposure, indicating the superior degradation of pollutants.