Equilibrium and Kinetic Studies on Adsorption of Methylene Blue Dye by ZnO Nanoparticles Synthesized by Hydrothermal Method

Metal oxides play significant role in many fields of nanotechnology including nanocatalysis, sensing, supermagnetic properties, fuel cells, nanoenergy storage and conservation. Dyes are synthetic compounds which have wide range of application in textiles, paints etc., and the dye effluents from the dyeing industries cause water pollution. In this present study, ZnO photocatalyst have been synthesized by hydrothermal method and were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and UV-VIS techniques. The XRD data revealed the hexagonal Wurtzite structure. The surface morphology of the synthesized ZnO photocatalyst was in the range of 50 -70nm in size which was obtained by SEM analysis. Degradation of methylene blue dye was studied using the synthesized ZnO photocatalyst. The process of degradation relies due to oxidation by highly reactive hydroxyl radicals. The factors such as ZnO dosage, pH and concentration of methylene blue dye were examined. Equilibrium and kinetic datum were derived from adsorption isotherms such as Freundlich and Langmuir models.