Efficient visible-light photooxidation of ciprofloxacin antibiotic over CoTiO3-impregnated 2D CeO2 nanocomposites synthesized by a sol-gel-based process

Photocatalytic oxidation of antibiotics over nanostructured semiconducting photocatalysts verified a capable method for averting future antimicrobial resistance crises. Designing a reusable and efficient photocatalyst is still in progress to sidestep obstructions of rapid recombination and instability. Here, a sol-gel-based strategy syn-thesized two-dimensional (2D) CeO2 nanoparticles. The 2D CeO2 were impregnated with various portions (3.0-12.0 wt%) of CoTiO3 to form CoTiO3/CeO2 with 60-80 nm in size and enhanced visible light harvesting with a minimum of 2.51 eV of the bandgap. The surface analysis revealed mesoporous structure formations with surface area ranging between 158 and 187 m2 g-1. The efficient photocatalytic oxidation of ciprofloxacin (CIPF), as a model antibiotic pollutant, was performed in 90 min utilizing 2.0 gL-1 of 9% CoTiO3/CeO2 with an oxidation rate constant of 0.0417 min-1. This advanced nanocomposite photocatalyst presented 96% of its original effi-ciency after the fifth recycle. This outstanding presentation of 9% CoTiO3/CeO2 is ascribed to the formation of CoTiO3/CeO2 heterojunction that provides excellent light harvesting and superior charge separation by the proposed emerging S-scheme mechanism.

Automated summary

Photocatalytic oxidation of antibiotics using nanostructured semiconducting photocatalysts is an effective method to prevent future antimicrobial resistance crises. Designing a reusable and efficient photocatalyst is a current challenge due to rapid recombination and instability issues. In this study, 2D CeO2 nanoparticles were synthesized using a sol-gel-based strategy and impregnated with CoTiO3 to form CoTiO3/CeO2 composite with enhanced visible light harvesting. The efficient photocatalytic oxidation of ciprofloxacin was achieved using 9% CoTiO3/CeO2, which showed excellent recyclability and high oxidation rate constant.