Sonophotocatalytic degradation of Orange II dye using low cost photocatalyst

The photocatalytic and sonophotocatalytic degradation of Orange II was investigated using a synthesized catalyst with low cost materials. Iron (III) oxide-titanium (IV) oxide (1% Fe) photocatalyst was synthesized by sol-gel method and pure titanium dioxide was used as photocatalytic reference material. Their crystallographic structures were determined by X-ray diffraction. The surface area and pore diameter was studied by Brunauer-Emmett-Teller method (N2 adsorption/desorption). The samples were characterized by Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX). SEM images show the formation of particles with spherical geometry. Synergistic effects of ultrasound and photocatalysis were demonstrated. Three different ultrasonic frequencies were tested 250 kHz, 500 kHz and 1000 kHz. The best catalytic activity (higher Orange II degradation efficiency) was obtained at 500 kHz. Test results show that it is possible the total decolourisation of the Orange II dye in aqueous media by the sonophotocatalytic process using visible light, without producing hazardous by-products. The process can be considered as a potential environmentally friendly technique for organic synthetic dyes degradation.