Photocatalytic activity of undoped and Ag-doped TiO2-supported zeolite for humic acid degradation and mineralization

The hybrid materials based on natural zeolite and undoped and Ag-doped TiO2, i.e., Z-Na-TiO2 and Z-Na-TiO2-Ag, were successfully synthesized by solid-state reaction in microwave-assisted hydrothermal conditions. Undoped TiO2 and Ag-doped TiO2 nanocrystals were previously synthesized by sol-gel method. The surface characterization of undoped TiO2/Ag-doped TiO2 and natural zeolite hybrid materials has been investigated by X-ray diffraction, DRUV-VIS spectroscopy, FT-IR spectroscopy, BET analysis, SEM microscopy and EDX analysis. The results indicated that anatase TiO2 is the dominant crystalline type as spherical form onto zeolitic matrix. The presence of Ag into Z-Na-TiO2-Ag was confirmed by EDX analysis. The DRUV-VIS spectra showed that Z-Na-TiO2-Ag exhibited absorption within the range of 400-500 nm in comparison with Z-Na-TiO2 catalyst. The enhanced photocatalytic activity of Z-Na-TiO2-Ag catalyst is proved through the degradation and mineralization of humic acid under ultraviolet and visible irradiation. (C) 2011 Elsevier Ltd. All rights reserved.