Author/Authors :
Azari, Babak Department of Chemistry - Faculty of Science - Islamic Azad University Rasht Branch, Rasht, Iran , Pourahmad, Afshin Department of Chemistry - Faculty of Science - Islamic Azad University Rasht Branch, Rasht, Iran , Sadeghi, Babak Department of Chemistry - Faculty of Science - Islamic Azad University Tonekabon Branch, Tonekabon, Iran , Mokhtary, Masoud Department of Chemistry - Faculty of Science - Islamic Azad University Rasht Branch, Rasht, Iran
Abstract :
White rice husk ash (RHA), an agricultural 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
found that zinc oxide NPs were encapsulated into the 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 had 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 electrohole
in ZnO semiconductor.
Keywords :
Environmental Catalysis , Green Chemistry , Photocatalysis , Nanoporous Materials , Nanocomposites
