Synthesis and characterization of ZnS-TiO2 photocatalyst and its excellent sun light driven catalytic activity.

The different wt% of ZnS loaded TiO2 (ZnS-TiO2) catalysts were successfully synthesized by precipitation cum sol-gel method and used for degradation of phenol dye, Phenol red sodium salt (PRSS) under natural sun light. Highly efficient 10.7 wt% of ZnS-TiO2 was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectrum (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL) and BET surface area measurements. ZnS-TiO2 is found to be more efficient than bare TiO2, TiO2-P25 and ZnS at pH 6.5 for the mineralization of PRSS dye. The effects of operational parameters such as the amount of photocatalyst and dye concentration have been analyzed. The mineralization of PRSS dye has been confirmed by chemical oxygen demand (COD) measurements. A dual mechanism has been proposed for the degradation of PRSS under solar light. This catalyst is found to be reusable.

Synthesis, characterization and photocatalytic properties of SnO2-ZnO composite under UV-A light.

The SnO2 loaded ZnO (SnO2-ZnO) was successfully synthesized by precipitation-decomposition method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM) images, energy dispersive spectrum (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL) and BET surface area measurements. The photocatalytic activity of SnO2-ZnO was investigated for the degradation of Acid Orange 10 (AO 10) in aqueous solution using UV-A light. SnO2-ZnO is found to be more efficient than commercial ZnO, bare ZnO, TiO2-P25 and TiO2 (Merck) at pH 12 for the mineralization of AO 10 dye. The effects of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photo mineralization of AO 10 dye have been analyzed. The mineralization of AO 10 has been confirmed by chemical oxygen demand (COD) measurements. A degradation mechanism is proposed for the degradation of AO 10 with SnO2-ZnO under UV-A light. This catalyst is found to be reusable.