Photoelectrocatalytic decolorization and degradation of textile effluent using ZnO thin films.

Zinc oxide (ZnO) thin films have been successfully deposited onto fluorine doped tin oxide coated glass at substrate temperature of 400 °C and used as electrode in photoelectrocatalytic reactor. The untreated textile effluent was circulated through photoelectrocatalytic reactor under UVA illumination for the decolorization and degradation. Textile effluent was decolorized by 93% within 3h at room temperature with significant reduction in COD (69%). High performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy (FTIR) analysis of samples before and after decolorization confirmed the degradation of dyes molecules from textile effluent into simpler oxidizable products. Phytotoxicity study revealed reduction in toxic nature of textile effluent after treatment.

Photo-corrosion inhibition and photoactivity enhancement with tailored zinc oxide thin films.

The nanocrystalline ZnO, TiO(2) and ZnO/TiO(2) films are deposited onto FTO-coated glass substrates by using spray pyrolysis technique. The structural, morphological, optical and photoelectrochemical properties of the ZnO, TiO(2) and ZnO/TiO(2) are investigated by X-ray diffraction, scanning electron microscopy, UV-Vis spectroscopy and photoelectrochemical techniques. XRD analysis shows that films are polycrystalline and having hexagonal and tetragonal crystal structure for pure ZnO and TiO(2). The photocatalytic degradation of methylene blue has been investigated with ZnO, TiO(2) and ZnO/TiO(2) photocatalysts. ZnO/TiO(2) thin films have proved quite effective mineralization of methylene blue, while pure ZnO and TiO(2) do not lead complete mineralization of methylene blue. The metabolites produced during degradation are analyzed by HPLC and Fourier transforms infrared spectroscopy. The by-products detected during degradation have been identified by GCMS technique.