Highly efficient light responsive BiOCl/AgI composites for photocatalytic degradation of 3-CP under visible and UV light irradiations

Abstract

Novel visible light sensitive BiOCl/AgI composites were synthesized by a facile precipitation technique. Samples were characterized by SEM (scanning electron microscope), XRD (X-ray diffraction), UV-DRS (UV-diffuse reflectance spectroscopy) and XPS (X-ray photoelectron spectroscopy). Photocatalytic activity of the samples was evaluated using 3-CP under UV–Visible irradiation. Compared to pure BiOCl, AgI and other BiOCl/AgI, the composites exhibited more catalytic activity under both UV and visible lights within 120 min. Optimal content of the BiOCl in the composite system was found as 40%. The excellent degradation of 3-CP under light was attributed to the efficient separation of photo-induced charge carriers, defect levels, iodide and chlorine $({{\text{I}}^ \cdot },{\text{C}}{{\text{l}}^ \cdot })$ radicals. The radical scavenging activities also illustrate that holes and superoxide radicals $({{\text{h}}^+})$ $~{\text{and}}\,({\text{O}}_{2}^{{ - \cdot }})$ are dominant agents in the photocatalytic degradation process. These results demonstrated that BiOCl/AgI systems are very useful to decompose persistent organic pollutants.