Highly efficient photocatalytic degradation of tetracycline antibiotic enabled by TiO2 nanodispersion

Abstract

The growing pollution of antibiotics poses a significant threat to the ecological environment and human health. Photocatalysis is a promising solution for eliminating tetracycline (TC), but developing efficient photocatalysts remains a critical and challenging task. Herein, TiO₂ nanodispersion is first used for the removal of TC in water. The as-prepared TiO₂ nanodispersion has a uniform size of 10 nm and a large specific surface area of 198.9 m²/g, exhibiting notable adsorption capacity, exceptional photocatalytic performance, and considerable stability. Under UV light, TiO₂ nanodispersion achieved 100 % degradation of TC within 60 min, using less than 1/5 of the catalyst dosage typically applied in most studies, and exhibited the highest catalytic activity, reaching 500 ${\text{mg}}_{\text{TC}}\bullet {{\text{g}}_{\text{catalyst}}}^{\text{-1}}{\text{h}}^{\text{-1}}$. Additionally, the photocatalytic rate constant of TiO₂ nanodispersion was 2.74 times higher than commercial P25. After five photocatalytic cycles, the catalyst maintained a high degradation efficiency of 94 %. Even under visible light, the degradation efficiency of TC by TiO₂ nanodispersion was approximately 90 % within 20 min, which was notably higher than that of P25 (63 %). Moreover, the as-prepared TiO₂ nanodispersion demonstrated outstanding photocatalytic degradation ability for other typical antibiotics (chlortetracycline, oxytetracycline, and ciprofloxacin), demonstrating its potential as an efficient photocatalyst for the treatment of antibiotic wastewater.