Application of Semiconductor Photocatalysis for Effective Elimination of Organic Contaminants from Sewage


Department of Science, Firoozkooh Branch,Islamic Azad University, Firoozkooh, Iran


The ZnO/SiO2 semiconductor nanophotocatalysis was synthesized via sol-gel method. Also, the
platinum particles were loaded on the ZnO/SiO2 nanoparticles by photoreductive method. The
structure of catalyst was confirmed by X-ray diffraction (XRD), scanning electron microscopy
(SEM) andfourier transform infrared spectroscopy (FT-IR). The XRD patterns of ZnO particles
displayed the nanoparticles have a wurtzite structure (hexagonal phase). The crystallite sizes were
calculated using Scheerer’s equation and were around 32nm. For photocatalytic test, decomposition
of Malachite Green oxalate (MG), as an organic pollutant was carried out by synthesized catalyst. A
comparison of degradation between bare catalyst and platinum loaded ZnO/SiO2nanoparticle under
UV-Vis light irradiation shows that the Pt-ZnO/SiO2 photocatalyst is more efficient than ZnO/SiO2
nanoparticles. Also, the activity of ZnO/SiO2nanoparticles in the visible light are minimal, while
loading of Pt in zinc oxide network displaced the band gap toward longer wavelengths (visible
light) and increased the photocatalysis activity of ZnO/SiO2 in the range of visible light.