Document Type: Original Research Paper
Department of Chemistry, Faculty of Science, Rasht Branch, Islamic Azad University, Rasht, Iran
Department of Chemistry, Faculty of Science, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran
White rice husk ash (RHA), an agriculture waste, was used as a silica source for MTW zeolite synthesis. The RHA-MTW zeolite derived from RHA was prepared by hydrothermal method at 150 °C in the presence of tetraethylammonium hydroxide. ZnO nanoparticles (NPs) were grown in zeolite substrates using a solid state reaction. The synthesized nanocomposite (NC) was characterized by XRD, SEM, DRS and TEM and tested as photocatalytic degradation of methylene blue (MB) dye from aqueous solution under ultraviolet (UV) light. The BET results indicated that pore volume and surface area of ZnO/RHA-MTW NC was smaller than RHA-MTW zeolite. On the basis of the obtained experimental results, it was founded that zinc oxide NPs were encapsulated into channels of RHA-MTW zeolite. The SEM and TEM images of ZnO/RHA-MTW NC confirmed the formation of RHA-MTW particles with size diameter of 2.5 µm and locating of zinc oxide NPs in channels of zeolite with an average size of between 35 nm. The results showed MB degradation reached 85 % under UV light. The MB indicated maximum adsorption at pH=9. The photocatalytic activity of ZnO was enhanced in the presence of zeolite due to reduction of recombination rate of the electro-hole in ZnO semiconductor.