Synergistic Effect of Microwave Calcination and Sonophotocatalytic Activity of TiO2-Montmorillonite on The Degradation of Direct Yellow 106 and Disperse Violet 1

Abstract

The TiO 2 -pillared montmorillonite nanoparticules (TiO 2 -Mt) were prepared by the sol-gel method, then applied for the elimination of dyes in solution: CI Direct Yellow 106 (DY106) (azo dye) and CI Disperse Violet 1 (DV1) (anthraquinone dye) by the sonocatalytic, photocatalytic and sonophotocatalytic processes, in order to test the efficiency of photocatalysts, while photolysis, sonolysis and sonophotolysis tests have been done previously. The photocatalysts (TiO 2 -Mt) were characterized by X-ray diffraction (XRD), X-ray fluorescence analysis (XRF), Brunauer-Emmet-Teller (BET), scanning electron microscopy (SEM) methods, thermal and thermogravimetric analysis (TG) / DTA) and the zero load point (pH pzc ). Aqueous solutions of dye of an initial concentration (50 mg.L -1 ), in the presence of 1 g.L -1 of photocatalyst, were irradiated using a mercury lamp (Hg) of 40 Mw / cm 2 and put in contact with an ultrasonic probe with a frequency of 20 kHz and a power of 750 W, providing the ultrasound. The results obtained indicate that a weak, good and better dye degradation rate has been observed successively by the application of the sonocatalytic, photocatalytic and sonophotocatalytic processes, where the latter has shown a synergistic effect, while the photocatalyst TiO 2 -Mt / MW showed significant efficiency during the degradation, due to the beneficial effect of the microwave calcination mode.