Visible Light Assisted Photocatalytic Degradation of Methylene Blue Dye and Mixture of Dyes Using ZrO2-TiO2 Nanocomposites

Abstract

Background: Different photocatalysts such as TiO2, ZnO and WO3 have been used for the degradation of organic pollutants. However, these materials have some limitations, which have been affected the catalytic efficiency in the various transformations. The composites of these materials with other oxides can produce better results by tuning structural as well as optoelectrical properties. The composite of TiO2 with ZrO2 has attracted attention due to its use in different areas, as ZrO2 and TiO2 have similar physicochemical features. Methods: This research contains the preparation of ZrO2-TiO2 nanocomposites by hydrothermal method and analysis of photocatalytic activity for the degradation of methylene blue and a mixture of dyes under visible light irradiation. Results: Physicochemical characterization of ZrO2-TiO2 nanocomposites has been studied by using different techniques. Prepared catalysts has shown anatase phase of TiO2 and tetragonal phase of ZrO2. XRD, FESEM and HRTEM have supported the nanocrystalline nature of the composites. The photocatalytic activity of composites and bare TiO2 samples were demonstrated for the degradation of methylene blue dye. Enhanced activity has been shown by composite having Ti:Zr 3:1 molar proportion, i.e., Ti3Zr. Effect of concentration of methylene blue, pH of the solution and catalyst loading have been studied by using Ti3Zr. In addition, the degradation of a mixture of three dyes, namely methylene blue, rhodamine B and methyl orange, has been studied. Conclusion: In summary, prepared ZrO2-TiO2 composites found to be nanocrystalline and visible light active. These catalysts have shown activity for photocatalytic degradation of methylene blue and a mixture of dyes.