Removal of Orange II Dye in Water by Visible Light Assisted Photocatalytic Ozonation Using Bi₂O₃and Au/Bi₂O₃Nanorods

Abstract

This paper presents the results of visible light assisted photocatalytic ozonation and other related oxidation processes for the removal of Orange II dye from water using Bi2O3 and Au/Bi2O3 nanorods prepared using microwave irradiation which was found effective compared to Bi2O3 particles prepared by conventional heat treatment method at 90 °C. Particularly, in the photocatalytic ozonation using Au/Bi2O3 nanorods, a fourfold increase in the rate was observed as compared to that in the absence of Au/Bi2O3. This is because tuning semiconductor materials into nanosize could create high quantum confinement of electron and hole to increase the illumination efficiency. In addition, the deposition of nanomaterial can also be employed to enhance the mechanical strength of devices. That is, deposited Au nanoparticles act as electron traps to impede electron/hole recombination.