Photocatalytic degradation of oxytetracycline by SiO2-TiO2-Ag electrospun fibers

The contamination and dispersion of antibiotics into the environment through effluents from sewage treatment plants have produced serious consequences like the generation of resistant bacteria, generating a health emer-gency, so the need arises to develop processes to eliminate antibiotics in effluents. One of the methodologies used is advanced oxidation where a complete degradation of antibiotics can be reached, among the advanced oxidation processes, photocatalysis stands out as an efficient degradation pathway of organic pollutants from a photocatalyst. In the present investigation SiO2-TiO2 fibers were obtained by sol-gel and electrospinning tech-niques which had a cylindrical morphology and a smooth surface free of defects with a diameter 266 +/- 62 nm. In increasing photocatalytic properties, the SiO2-TiO2 fibers were doped with silver by electrodeposition resulting in the deposition of particles with a branched dendritic morphology with a size of approximately 1 mu m. The characterization of SiO2-TiO2-Ag fibers by infrared in the fibers eluted bands characteristic of the Si-O-Si and Ti-O-Ti bonds, and by means of the X-ray diffraction were identified crystalline phases corresponding to the anatase and rutile of the Titania, as well as face-centered cubic silver. Oxytetracycline was used as a contaminant to investigate the photocatalytic performance of SiO2-TiO2-Ag material, where from an initial concentration of 30 ppm in the presence of SiO2-TiO2 fibers its degradation percentage was 65%, unlike 90% in 7 h using silver-doped fibers. The increased degradation of oxytetracycline is attributed to the success in decreasing the banned band of SiO2-TiO2 fibers from 3.1eV to 2.5eV to silver doping.