Sunlight-driven photodegradation of oxytetracycline antibiotic by BiVO4 photocatalyst

The focus of the present work is laid on a development of a bismuth vanadate (BiVO4) photocatalyst with a high solar-light-responsive property and a promising charge carrier separation efficiency. The photocatalyst was prepared by a green and environmentally friendly hydrothermal method without addition of surfactant, organic solvent, or capping agents. The sample showed monoclinic phase with band gap energy of 2.34 eV. The absorption bad edge of 530 nm indicates the promising visible-light- responsive property of the sample. The synthesized photocatalyst also showed truncated-bipyramidal morphology with well faceted structure of the particles indicating high surface quality of the sample. The photoactivity of the prepared BiVO4 photocatalyst was elucidated by monitoring photodegradation of oxytetracycline (OTC) antibiotic. An enhanced efficiency of 83% under sunlight was achieved after 240 min. The photodegradation reaction followed the first-order kinetics model with a rate constant of 0.0097 min(-1). Hydroxyl radicals play a major role in OTC antibiotic degradation. The chemical structure of the photocatalyst remained stable after photodegradation. The photocatalyst still shows high efficiency even after the fifth run implying its advantages of structural stability and reusability. This research shows a high potential of the prepared BiVO4 photocatalyst for detoxification of OTC antibiotic in wastewater.