Investigation of photo-catalytic degradation of methylene orange dye using titanium dioxide–zinc oxide nanocomposites

Abstract

Excessive use of colored dyes in textile industries has raised the issue of water contamination in Pakistan. To reduce such contaminations, the photocatalytic treatment of the effluent is adopted as a simple and economically solution. In the present work, photocatalytic degradation of methylene orange (MO) is carried out in the presence of titanium dioxide–zinc oxide (TiO2/ZnO) nanocomposites as catalysts under UV light irradiation. The nanocomposites of titanium dioxide–zinc oxide (TiO2/ZnO) were prepared with different weight ratios of ZnO in TiO2 using ball milling technique. The crystalline structures and properties of the as synthesized TiO2/ZnO nanocomposites were investigated via x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. XRD results showed that the crystallization behavior of the nanocomposite changes with the change in weight ratio of ZnO in TiO2. The SEM profiles revealed that the surface morphology of the nanocomposite regularizes with an increase in weight ratio of ZnO in the composite. The photocatalytic treatment suggested that TiO2/ZnO nanocomposite with 1:1 weight ratio shows better photocatalytic activity among all the tested weight ratios.