Hydrothermal synthesized zinc oxide/kaolinite for photo-decolorization of methyl violet

A composite of zinc oxide supported on kaolinite (ZnO/Kao) using Indonesian natural kaolinite minerals was synthesized by a hydrothermal method. The role of the material as a photocatalyst in methyl violet (MV) photocatalytic decolorization was tested. As-prepared material was characterized by X-ray diffraction, scanning electron microscope analysis, transmission electron microscope analysis, and diffuse reflectance UV-Vis diffuse reflectance spectroscopy. The results showed that significant photocatalytic activity for the photocatalytic decolorization of MV was found compared to ZnO. The increased photocatalytic activity was related to the band gap energy associated with the formation of nanoparticles (crystallite size of 46-74 nm). In addition, the material demonstrated high decolorization efficiency as measured by a turnover number (TON) and photocatalyst stability at varied pH ranges from 4-10. The results suggest that the material may be a promising photocatalyst for photocatalytic decolorization of organic dyes in wastewater.