Decoration engineering induced MoS2QDs/BiOBr heterostructures for significantly enhancing visible light photocatalytic capability for the organic dyes and antibiotics removal

A novel MoS 2 quantum dots decorated BiOBr heterostructure photocatalyst has been successfully fabricated by a facile hydrolysis approach. The MoS 2 QDs are prepared through an ultrasound-exfoliation method by MoS 2 nanosheet. The structure, morphology, elemental composition and optical absorption properties of materials have been detailedly investigated by X-ray powder diffraction (XRD), FT-IR spectrum, Raman spectrum, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM (HRTEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence spectra (PL), respectively. It can be observed that MoS 2 QDs with a diameter of about 5 nm are uniformly and firmly dispersed on the surface of the BiOBr. The MoS 2 QDs/BiOBr heterostructures show excellent photocatalytic activity both towards rhodamine B dyes and ciprofloxacin under visible light irradiation. It can be attributed to the synergistic effect of MoS 2 QDs/BiOBr heterostructures between MoS 2 QDs and BiOBr, which can promote the separation of photo-induced carriers and absorption of visible light. A heterojunction model based on the charges transfer mechanism has been proposed. Furthermore, the scavenger experiments and repeated experiments are conducted. The superior photocatalytic activity and excellent stability of MoS 2 QDs/BiOBr heterostructures can be a promising choice for practical application of water purification.