Photocatalytic and Antimicrobial Properties of Electrospun TiO₂-SiO₂-Al₂O₃-ZrO₂-CaO-CeO₂ Ceramic Membranes

In this study, TiO₂-based ceramic nanofiber membranes in the system of TiO₂-SiO₂-Al₂O₃-ZrO₂-CaO-CeO₂ were synthesized by combining sol-gel and electrospinning processes. In order to investigate the thermal treatment temperature effect, the obtained nanofiber membranes were calcined at different temperatures ranging from 550 to 850 °C. Different characterization methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and high-resolution transmission electron microscopy (HR-TEM) were conducted on the obtained membranes to investigate the structural and morphological properties of the nanofibers. The Brunauer-Emmett-Teller surface area of the nanofiber membranes was very high (46.6-149.2 m²/g) and decreased with increasing calcination temperature as expected. Photocatalytic activity investigations were determined using methylene blue (MB) as a model dye under UV and sunlight irradiation. High degradation performances were achieved with the calcination temperatures of 650 and 750 °C because of the high specific surface area and the anatase structure of the nanofiber membranes. Moreover, the ceramic membranes showed antibacterial activity against Escherichia coli as a Gram-negative bacterium and Staphylococcus aureus as a Gram-positive bacterium. The superior properties of the novel TiO₂-based multi-oxide nanofiber membranes proved as a promising candidate for various industries, especially the removal of textile dyes from wastewater.