Photocatalytic decoloration of three commercial dyes in aqueous phase and industrial effluents using TiO2 nanoparticles

TiO2 sol was synthesized under mild conditions (25 +/- 1 degrees C and ambient pressure) by hydrolysis of titanium isopropoxide in aqueous solution and subsequent reflux to enhance crystallization. The material was characterized by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared. The synthesized sample presented a pure phase anatase with nanometric particle size. The photodegradation of reactive dyes (malachite green, methylene blue, and rhodamine B) and industrial effluents was elucidated in aqueous suspension containing titania nanoparticles under UV irradiation. Also, the effect of pH in nanoparticle synthesis and role of catalyst dose and dye concentration were evaluated. The experimental result showed that particles synthesized by sol-gel method are of 20-40nm anatase form with cuboidal structure and OH- as a major functional group. These particles showed efficiency to degrade dyes up to 98% and industry (paint and textile) effluents can be decolorized in the TiO2/UV system.