Preparation and photocatalytic properties of visible light driven Ag-AgCl-TiO2/palygorskite composite

A visible light responsive photocatalyst consisting Ag-AgCl composite dispersed over TiO2/palygorskite (Ag-AgCl-TiO2/palygorskite) was synthesized via a facile method. The as-obtained samples were characterized by X-ray diffraction (XRD), Raman spectra, nitrogen adsorption-desorption measurements, UV-visible diffused reflectance spectra (UV-vis DRS) and X-ray photoelectron spectroscopy (XPS). The results confirmed that the localized surface plasmon resonance of Ag nanoparticles in the Ag-AgCl-TiO2/palygorskite composite resulted in a plasmon resonance absorption band in the visible region. The photocatalytic activity of the composite was evaluated by degradation of Rhodamine B (RhB) and 4-nitrophenol (4-NP) under visible light irradiation. The results indicate that Ag-AgCl-TiO2/palygorskite catalyst exhibited stronger adsorption capacity and higher photocatalytic degradation efficiency for RhB dye than the well-known commercial P25 TiO2 photocatalyst, the TiO2/palygorskite, the Ag-TiO2/palygorskite, the AgCl-TiO2/palygorskite and the Ag-AgCl composite. In addition, the photoactive radical species involved in the degradation reaction also have been investigated by quenching experiments. (C) 2015 Elsevier B.V. All rights reserved.