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

Abstract

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