Pillared clays impregnated with TiO₂: Efficient photocatalyst for wastes degradation

Full text: The present study aimed to investigate the use of montmorillonite clays impregnated with titanium dioxide (TiO₂) in the treatment of organic effluents, using the heterogeneous photocatalysis process [1]. Titanium trichloride (TiCl₃) was used as precursor to obtain TiO₂ in the clays [2]. This impregnation was performed on commercial aluminum pillared clays in the presence of two separate solvents, ketone and water, to investigate their influence on the impregnation process. The degradation reactions were carried out in a photocatalytic reaction system using a 250 W mercury lamp with a methylene blue solution of 1000 ppm. The reaction was performed under different conditions to evaluate the influence of each parameter (stirring time, the influence of the solvent using hydrogen peroxide or radiation and time of use) on degradation efficiency. The materials were characterized using X-ray diffractometry (XRD), X-ray fluorescence (FRX), scanning electron microscopy (SEM) and textural analysis by adsorption of N2. The best impregnation results were obtained using ketone as the solvent. The most satisfactory degradation results (86%) were obtained with this same clay, in agitation and in the presence of hydrogen peroxide. References: [1] Lu, G.; Linsebigler, A.; Yates, J. T. Journal of physical chemistry, v. 99, n. 19, p. 7626–7631, 1995 [2] Kaneko, T. et al. Journal of Porous Materials, v. 8, n. 2, p. 99–109, 2001. (author)