Photocatalytic activity to ciprofloxacin and physico-chemical properties of TiO2synthesized by different methods

TiO2 nanoparticles were synthesized by sol–gel and hydrothermal methods from Titanium (IV) isopropoxide. The obtained materials were studied for photocatalytic removal of antibiotic ciprofloxacin under UVA light. The samples were characterized using x-ray diffraction, transmission electron microscopy, scanning electron microscopy and N2-physisorption. The most active samples were obtained at pH 1.0 via sol–gel synthesis (SG TiO2 pH 1.0); and using 2-propanol at 110 °C via hydrothermal method (HT TiO2 Pr 110). The SG TiO2 pH 1.0 sample demonstrated higher crystallinity but lower specific surface area (23 m2/g) compared to the HT TiO2 Pr 110 sample (315 m2/g). Both samples demonstrated good photoactivity after 120 min, removing ciprofloxacin up to 99%. However, adsorption accounted for most antibiotic removal by the HT TiO2 Pr 110 sample, while photocatalysis played predominant role in the case of the SG TiO2 pH 1.0 sample.