Novel recyclable composite BiOBr/chitin-Fe3O4 with enhanced visible-light photocatalytic degradation of the antibacterial agent ciprofloxacin

ABSTRACT In this study, novel recyclable composite BiOBr/chitin-Fe 3 O 4 was synthesized by a solvothermal method using magnetic chitin chelating bismuth oxybromide (BiOBr) as precursor. The morphology, structure, photoelectric properties and chemical composition of the obtained samples were explored extensively by various characterization techniques. Due to the introduction of Fe 3 O 4 and chitin, the composite BiOBr/chitin-Fe 3 O 4 has multi-functions in enlarging photo response performance, reducing the band gap, increasing specific surface area and inhibiting recombination rate, which are essential to improve the photocatalytic efficiency. Using ciprofloxacin as target pollutant, the composite showed excellent photocatalytic performance under visible light irradiation, the apparent rate constant value of BiOBr/chitin-Fe 3 O 4 is 5.8 times higher than that of pure BiOBr. The composite BiOBr/chitin-Fe 3 O 4 could be recycled and reused conveniently and effectively, and the catalyst possessed good photocatalytic stability with the degradation efficiency remaining unchanged even after five times circle. The possible degradation mechanism was discussed on the basis of experiments.