Preparation and characterization of new nano- photocatalysts for purification of industrial waste water

Abstract

The preparation of TiO2 photocatalysts has been carried out using three types of surfactants: cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl benzene sulfonate (DBS) and nonylphenol ethoxylate (NPE) (in acidic medium at pH 3-4 and in basic medium pH 8-9). Doping TiO2 in acidic medium with different contents of MWCNTs (0.01, 0.03, 0.05 and 0.1%) and doping with two transition metal oxides (Fe, Cu and Fe-Cu). All photocatalysts were prepared by the sol-gel method to have the catalysts particles in the nano-scale. Characterization of current TiO2 photocatalysts has been carried out using XRD, SEM, TEM, BET, UV-vis, FT-IR and Raman spectra measurements. These catalysts were used for the photodegradation of naphthalene (NP) applying tungsten lamp (wave length irradiation at 300-800 nm) for 3 hours. In photocatalytic activity measurements, high performance liquid chromatography (HPLC) has been used to evaluate degradation product of the pollutant. The TiO2 parent catalyst acquired surface area (16m2g-1) and pore volume (0.003cc/g) and attained photodegradtion of NP of 37% after 180 min. However, using 0.03%CNT/CTAB-A catalyst which is the most active one (degradation percent 100% after 60 min), its surface area and pore volume values were 137m2g-1 and 0.452cc/g, respectively