MJFAS 11-2015-170

Photocatalytic decolorization of methylene blue using zinc oxide supported on
mesoporous silica nanoparticles

Various dyes that are used in textile, paper, cosmetics and plastics industries may produce harmful
effects on the health of living organisms and the environment if not treated properly before being
discharged into water bodies. Among many techniques, photocatalytic process is one of the promising
treatment for these dyes. Zinc oxide (ZnO) is well-known comparable with TiO2 due to its unique
properties and numerous advantages. While, mesoporous silica nanoparticles (MSN) is an excellent
solid support for heterogeneous catalysts due to its high surface area, thermal and mechanical stability,
highly uniform pore distribution, tunable pore size, and unique hosting properties. Therefore, in this
study, ZnO/MSN (ZM) catalysts were prepared and its physicochemical properties was characterized
by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The catalyst was
tested on the photodecolorization of methylene blue (MB) dye. The results showed that the interaction
between ZnO and MSN support could enhanced the photocatalytic activity. The 0.5 g L-1 of 5ZM was
found to give the highest degradation (80 %) of 10 mg L-1 of MB solution at pH 7 after 3 h under UV
light irradiation. The photodecolorization followed the pseudo first-order Langmuir-Hinshelwood
kinetic model. This study demonstrated that the prepared 5ZM has a potential to be used in
photocatalytic degradation of various dyes as well as organic pollutants.