It also confirms the absence of macropores and the presence of micro and mesopores. The BET surface area for TiO 2/SiO 2 nanocomposite is found to be 303 m 2/g and pore size distribution has average pore diameter about 10 nm. The crystallite size of the as-synthesized samples was calculated by Scherrer’s formula. The UV–Vis spectrum of as-synthesized samples shows similar absorption in the visible range. The synthesized samples are characterized by X-ray diffraction, UV–Vis spectroscopy, Fourier transform infrared spectroscopy, Brunauett–Emmett–Teller and field-dependent photoconductivity. Mesoporous TiO 2, SiO 2 nanoparticles and TiO 2/SiO 2 nanocomposites were successfully synthesized by sol–gel method using titanium (IV) isopropoxide, tetra-ethylorthosilicate as starting materials. Mesoporous materials have been of great interest as catalysts because of their unique textural and structural properties. Jacques I (1971) Pankove - Optical processes in semiconductors.The use of titania–silica in photocatalytic process has been proposed as an alternative to the conventional TiO 2 catalysts. Irimpan L, Deepthy A, Krishnan B, Nampoori VPN, Radhakrishnan P (2007) Size dependent fluorescence spectroscopy of nanocolloids of ZnO. Koch U, Fojtik A, Weller H, Henglein A (1985) Chem Phys Lett 122:507 Wang X, Feng Z, Shi J, Jia G, Shen S, Zhou J, Li C (2010) Phys Chem 12:7083–7090 Zhao Y, Li C, Liu X, Feng Gu, Jiang H, Shao W, Zhang L, He Y (2007) Mater Lett 61:79–83 Tang H, Berger H, Schmid PE, Levy F (1993) Solid State Commun 87(9):847–850 Shirke BS, Korake PV, Hankare PP, Bamane SR, Garadkar KM J Mater Sci Mater Electron. Serpone N, Lawless D, Khairutdinov R (1995) J Phys Chem 99:16646 Plugaru R, Cremades A, Piqueras J (2004) J Phys Condens Matter 16:S261–S268
Absorption spectra of tio2 nanoparticles series#
Hudec B, Husekova K, Dobrocka E, Lalinsky T, Aarik J, Aidla A, Frohlich K (2010) IOP Conf Series Mater Sci Eng 8:012024 Nakato Y, Tsumura A, Tsubomura H (1982) Chem Phys Lett 85:387 Ito S, Yamada Y, Kuze M, Tabata K, Yashima T J Mater Sci 39(18):5853–5856 Singh Nalwa H (2000) Nanostructured materials and nanotechnology. It is observed that the surface state emission basically consists of two categories of emission. The emission spectrum of annealed nanocrystallites is also having these four band emissions. We have observed new emission bands at 387 nm,421 nm, 485 nm, 530 nm and 574 nm wavelengths, first one (387 nm) being emission due to annihilation of excitons while remaining four could be arising from surface states. The fluorescence property of the TiO 2 colloidal nanoparticles studied by the emission spectrum confirms the presence of defect levels caused by the oxygen vacancies. The XRD study confirms that the size of the colloidal nanoparticle is around 4 nm which the HRTEM analysis indicates the sizes of the colloidal nanoparticles are in the range of 2.5 nm. The synthesized samples are characterized by X-ray diffraction (XRD), HRTEM and FTIR. TiO 2 colloidal nanoparticles and nanocrystals are prepared by hydrolysis of titanium isopropoxide employing a surfactant-free synthetic hydrothermal method.
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