Fe3O4/BiOCl photocatalyst with magnetic recovery property for solar-light-responsive removal of Rhodamine B dye

Binary Fe₃O₄/BiOCl photocatalyst was fabricated successfully via a facile ultrasonic route. The magnetic Fe₃O₄/BiOCl was used for solar-light-driven detoxification of Rhodamine B (RhB) dye. The prepared binary photocatalyst displayed mainly the diffraction peaks of BiOCl. The energy gap of BiOCl and Fe₃O₄/BiOCl was 3.37 eV, and 2.55 eV, respectively. The Fe₃O₄/BiOCl photocatalyst revealed lower fluorescence intensity, compared to the pristine BiOCl, indicating the enhanced carrier separation rate. The result corelates well with the improvement in photocatalytic activity of the magnetic Fe₃O₄/BiOCl photocatalyst. High photocatalytic efficiency of 100% was achieved after 90 min of sunlight irradiation. The degradation of RhB dye fits nicely with the first-order kinetic model revealing the maximum rate constant of 0.0113 min^–1. The binary photocatalyst still maintains the excellent photodegradation activity after the fifth cycle of use. The trapping technique reveals that photogenerated electrons and superoxide anion radicals play a key role in RhB detoxification. The present work provides a promising way to generate the sunlight-active semiconducting catalyst, with magnetic separable property, for detoxification of RhB dye in an aqueous phase.