Abstract
Titanium dioxide nanoparticles successfully anchored into 3-D mesoporous material (TUD-1) using a sol-gel preparation strategy. The Ti/Si ratio varied between 0 and 1.0 in the prepared catalysts. The prepared materials showed mesoporous texture with relatively large surface area and a unique pore size distribution according to N-2 adsorption, XRD, UV-vis./DR and TEM measurements. The solid materials consist of amorphous silica with no indication of the TiO2 crystallites. These catalysts were used in the photodegradation of methylene blue (I), peach red azodye (II) and tetrazine (III) in their aqueous solutions through irradiation by visible light (X = 447 nm). The biggest dye adsorption in dark is observed by the catalyst with Ti/Si equals 10. Photodegradation of organic dyes was followed by recording UV-vis. spectra of the dyes and total carbon content of the dye solutions at different irradiation periods.
The newly developed Ti-TUD-1 photocatalysts showed excellent activity towards the degradation of the tested organic dyes. Up to 98% of azodyes were successfully removed from the contaminated wastewater. Moreover, the catalysts showed remarkable stability under the relatively mild irradiation conditions used. Repeated photodegradation tests demonstrated remarkable reproducibility and showed no decrease in photocatalytic activity after 5 cycles.