Photocatalytic activity to ciprofloxacin and physico-chemical properties of TiO₂ synthesized by different methods

Abstract

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.

Keywords:

• Antibiotics
• ciprofloxacin
• heterogeneous photocatalysis
• hydrothermal synthesis
• sol–gel synthesis
• TiO₂

Additional information

Funding

AK gratefully acknowledges the grant from Erasmus + Program-International Credit Mobility project # 2019-1-IE02-KA107-000650 funded by the European Commission that made it possible to work at the University of Limerick, Ireland.