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

Abstract

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 synthesized 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 efficiency 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.