SYNTHESIS AND CHARACTERIZATION OF NANOCOMPOSITES KAOLINITE/TITANIUM DIOXIDE DOPED WITH NIOBIUM IONS

Abstract

Purpose: The goal of the present work is the synthesis and characterization of a heterogeneous photo catalystsbased on kaolinite, titanium dioxide and niobium ions to help in treatments of effluents containingdrugs such as ceftriaxone sodic. Methods: KaNb, KaTiNb and KaTi were synthesized varying the mass of Ti and Nb between 1 to 10 wt %. A mass of niobium ammonium oxalate, in 2 g of kaolinite, 40 mL of isopropanol and 0,2 mL of acetic acid. All the solutions were keeped on constant shaking for 24 hours. Then these materials were heated at 400, 700 and 1000oC. Results: X ray powder diffractionshown that non-heated materials present all the typical reflection of kaolinite and this reflection were maintained on materials heated until 400oC.The materials treated at 700 and 1000 oC not shown the typical reflection of kaolinite due the change of structure of kaolinite to metakaolinite structure. The typical phases of TiO 2 were not observed due the dilution of the titanium dioxide and niobium on clay matrix. The same effect was observed on FTIR, the principal bands of Ti-O and Nb-O appear at the same region of Al-O and Si-O from kaolinite. The UV-Vis spectra of solids shown the typical bands of the semi conductor at 260 nm and confirming the presence of TiO 2 on kaolinite surface. Conclusion: All the photocatalysts were synthesized and characterized.As previously observed by our group photocatalysts containing the mixed phase of TiO 2 /M + on the surface of the lamellar material displayed good activity and can degrade many contaminants.