Sprayed nanostructured TiO2 films for efficient photocatalytic degradation of textile azo dye

Spray pyrolysis procedure for preparation of nanostructured TiO2 films with higher photocatalytic effectiveness and longer exploitation life is presented in this study. Thin films of active nanocrystalline TiO2 were obtained from titanium isopropoxide, stabilized with acetyl acetone and characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The activity of sprayed nanostructured TiO2 is tested for photocatalytic degradation of Reactive Black 5 dye with concentrations up to 80 ppm. Interesting result of the work is the reduction of toxicity after photocatalytic treatment of RB5 with TiO2, which was confirmed by the lower percentage of mortality of Artemia salina. It was proved that the film thickness, conditions of post deposition treatment and the type of the substrate affected significantly the photocatalytic reaction. Taking into account that the parameters are interdependent, it is necessary to optimize the preparation conditions in order to synthesize photocatalytic active films.

► Nanostructured TiO2 films on alumina foil were prepared by spray pyrolysis.
► The films exhibit higher photocatalytic activity towards diazo dye degradation.
► The TiO2 thin films preserve the efficiency at high dye concentrations up to 80 ppm.
► The TiO2 films demonstrated high activities after even four photocatalytic tests.
► Significant toxicity reduction of RB5-solution after treatment with TiO2.