Complete Detoxification of the Ofloxacin Antibiotic by Magnetically Separable Fe₃O₄/AC/BiOCl Photocatalysts

A ternary photocatalyst composing activated carbon (AC), Fe₃O₄ and BiOCl was synthesized via an ultrasonic method. The magnetic Fe₃O₄/AC/CTAB-BiOCl photocatalyst was used for the degradation of the ofloxacin antibiotic under UV light and natural solar light. The prepared ternary photocatalyst showed mainly the diffraction peaks of BiOCl together with those of Fe₃O₄. The band gap values of 3.20, 3.27, and 3.18 eV were recorded from CTAB-BiOCl, AC/CTAB-BiOCl, and Fe₃O₄/AC/CTAB-BiOCl photocatalysts, respectively. The ternary photocatalyst showed the smallest photoluminescence signal, in comparison to those obtained from the other photocatalysts, indicating improved carrier separation efficiency. The finding agrees well with the enhanced photocatalytic activity of the magnetic photocatalyst. A promising photocatalytic efficiency of 100% was reached after only 60 min of UV light (a mercury lamp, 135 W) and natural solar light irradiation. The degradation of the OFL drug correlates well with a first-order reaction, revealing a great reaction rate coefficient of about 0.1158 min^-1. The prepared ternary photocatalyst still maintains excellent photoactivity even after the fifth cycle of use. The trapping method indicates the great role of the photogenerated electrons and hydroxyl radicals in OFL removal. This research demonstrates a new route to generate a sunlight-responsive catalyst, with magnetically separable properties, for the detoxification of the OFL drug in wastewater.