No abstract

No abstract

A special sol-gel method is used to successfully synthesize spherical TiO 2 /SiO 2 nanoparticles from titanium tetra-isopropoxide and tetraethoxysilane precursors. The prepared samples were dried at 110 °C and calcined at 300 °C, 500 °C and 800 °C. The formed titanium oxide is in a tetragonal structure with significant pure anatase and rutile phase. The estimated particle size of spherical nanostructure was ~18.40 nm through transmission electron microscopy (TEM) and showed a larger Brunauer Emmett Teller (BET) surface area of 310 m 2 /gm for the sample calcined at 300 o C. The TiO 2 cores are enclosed within SiO 2 particles with an average crystallite size of 10-20 nm. In atomic force microscopy (AFM) images, the same sample displayed the well-structured and macro-pore free morphology. Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of Ti-O-Ti, Si-O-Si and Ti-O-Si metal oxide bond to raise anatase structure of TiO 2 . The ultraviolet visible spectroscopy (UV-Vis) of as synthesized samples revels the visible absorption region. Photoluminescence spectroscopy (PL) shows a decrease in emission intensity and the emission band splits into sharp peaks to signify the decrease in recombination rate. These properties predict the materials to photo-degrade organic dyes. The material's photocatalytic activity was evaluated for degradation of methylene blue and methyl orange dyes. It is found that the sample calcined at 300 °C exhibits a better photodegradation for methylene blue (MB, 80-85%) than methyl orange (MO, 70-75%) under mercury light within 2 hours.

No abstract

No abstract