Synthesis and characterization of zeolite materials functionalized with undoped and N-doped TiO2 nanocrystals

The aim of this paper was the syntheses and characterizations of functionalized zeolite materials with undoped and nitrogen-doped TiO2 nanocrystals. These materials were obtained by using alternative methods, namely sol-gel and hydrothermal, directly from precursors. The synthesis of TiO2 by sol-gel and hydrothermal methods was achieved in order to compare the crystalline structures and morphologies of TiO2 on the surface of the zeolite within the obtained hybrid materials. The obtained materials were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDAX). The XRD results revealed that the natural zeolite used for the synthesis is mostly clinoptilolite and the anatase form of TiO2 for both applied methods. As it was desired, no the rutile phase of TiO2 was evidenced. The surface morphology observed by SEM analysis showed that TiO2 (spherical form) nanocrystals were attached on the zeolite surface. Therefore, the IR spectra confirmed the presence of TiO2 in to the zeolite lattice. The presence of the nitrogen ion in the materials obtained by both synthesis methods was also confirmed by EDAX spectra.