Preparation and photocatalytic properties of visible light driven Ag- AgBr/attapulgite nanocomposite

摘要

An efficient visible light photocatalyst of Ag-AgBr/attapulgite nanocomposite was prepared via the reaction between Ag~+ and Br~- ions in the presence of attapulgite and then reducing partial Ag~+ ions to Ag~0 species via the light-induced chemical reduction. Characterization methods, such as X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-visible diffused reflectance spectroscopy (UV-vis DRS) were employed to study the phase structure, chemical state and optical properties of the nanocomposite. The Ag-AgBr/attapulgite nanocomposite exhibited an efficient photocatalytic activity for the degradation of Rhodamine B (RhB) aqueous solution under visible light radiation (λ>400 nm). In addition, the photoactive radical species involved in the degradation reaction have been investigated by using the HO-trapping photoluminescence (PL) spectra and quenching experiments. A possible photodegradation mechanism of RhB dye by the Ag-AgBr/attapulgite nanocomposite was postulated.