DIRECT ULTRASONIC SYNTHESIS OF WO3/TiO2 NANOCOMPOSITES AND APPLYING THEM IN THE PHOTODECOLORIZATION OF EOSIN YELLOW DYE

Abstract

This research reported a direct, environmentally friendly, economical, and simple method of using an ultrasonic instrument as a green technique to combine WO3 with TiO2 in ratios 0.5:1, 0.25:1, and 0.16:1 as composites 1, 2 and 3 respectively. Powder X-Ray Diffraction data identified the mean crystalline sizes of the commercial WO3, commercial TiO2, and of the prepared WO3/TiO2 nanocomposites in the different ratios in ranged from 17.897 nm to 48.672 nm. AFM analysis noted the surface morphology for all studied samples is spherical. The mean crystal sizes and practical sizes for prepared composites are found to be in the nanometer range, and these values rise with the raising in the TiO2 quantity in prepared nano-composites. The incorporated of W with Ti in the matrix is successful happened; because the ionic radius of W6+ is fewer values than it for Ti4+. The band gaps values for all samples have been investigated. The band gaps of prepared nanocomposites 1, 2, 3, and TiO2 are occurred as an indirect type, while the band gap of WO3 is found as direct type. The studied samples were tested by using them as photocatalysts in the decolorization of an aqueous solution, the eosin yellow dye Edecol.%. The sequence of decoloration grows from the left to the right as: Edecol.% (composite 3) Edecol.% (WO3) Edecol.% (TiO2) Edecol.% (composite 2) Edecol.% (composite 1). The activity of WO3 is inhibited with addition of H2O2 to the aqueous solution of eosin yellow dye because of the formation of peroxotungstic acid (WO3H2O2.H2O or WO2(O2)H2O.nH2O), but the modified surface by incorporation of TiO2, improves the activity hence, nano-composite 1 in the ratio of 0.5:1 is given a maximum photodecolorization efficiency of this dye and changed from 25.11% to 73.88%.