Highly Efficient Removal of Organic Dyes by Novel As-synthesized AgBr/montmorillonite Composite

Abstract

A facile deposition method has been developed for large-scale synthesis of visible-light-driven AgBr/montmorillonite composite catalyst for the first time. The as-synthesized samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and Brunauer-Emmett-Teller (BET) surface area analysis, respectively. Through the combined action of adsorption and photodegradation, the as-prepared AgBr/montmorillonite composite exhibited a higher removal efficiency for rhodamine B (RhB) than that of Na-montmorillonite and AgBr. For the methyl orange (MO) removal, the AgBr/montmorillonite composite possessed a superior photocatalytic performance compared with Namontmorillonite and AgBr. The enhanced photocatalytic activity of AgBr/montmorillonite composite can be attributed to the effective separation of the electron-hole pairs. In AgBr/montmorillonite suspension, the superoxide radicals are the main reactive oxygen species for dye degradation under visible light illumination.

Keywords

AgBr/montmorillonite / adsorption / photocatalysis / dye / photocatalytic mechanism