Microwave-assisted synthesis of few-layered MoS2/BiOBr hollow microspheres with superior visible-light-response photocatalytic activity for ciprofloxacin removal

Abstract

BiOBr hollow microspheres attached to few-layered molybdenum disulfide (MoS₂) were prepared by an ethylene glycol (EG)-assisted microwave process in the presence of 1-hexadecyl-3-methylimidazolium bromine ([C₁₆mim]Br). The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and UV-vis diffuse reflectance spectroscopy (DRS). During the reaction process, the ionic liquid [C₁₆mim]Br acts as not only a solvent and Br source, but also as a microwave-absorbing agent and template for the fabrication of MoS₂/BiOBr hollow microspheres. In addition, the photocatalytic activity of MoS₂/BiOBr was evaluated for the degradation of ciprofloxacin (CIP) and Rhodamine B (RhB) under visible light irradiation. The results indicated that 0.2 wt% MoS₂/BiOBr microspheres exhibit higher photocatalytic activity than BiOBr. A possible photocatalytic mechanism based on the relative band position of MoS₂ and BiOBr was proposed.