Preparation and Properties of Thin Films Based on Titanium, Silicon, and Nickel Oxides
A. N. SHAMSUTDINOVA, V. V. KOZIK
Tomsk State University, Tomsk, Russia
Keywords: золь-гель синтез, пленкообразующий раствор, диоксид титана, диоксид кремния, тонкие пленки, оптические свойства, каталитическая активность, sol-gel synthesis, film-forming solution, titanium dioxide, silicon dioxide, thin films, optical properties, catalytic activity
Abstract
Thin films of the composition TiO2, TiO2-SiO2, TiO2-SiO2-NiO were obtained by the method of sol-gel synthesis from film-forming solutions, resistant to destruction. The optimum conditions for the preparation of titanium, silicon and nickel oxides from film-forming solutions were determined. It was found that at the simultaneous introduction of tetrabuthoxytitanium, tetraethoxysilane and/or of nickel chloride, the rheological stability of film-forming solutions was reduced. It was determined by ellipsometry methods that the thickness of porous TiO2 films with a refractive index of 2.307 was equal to 12 nm. The introduction of silicon and/or nickel oxides in the films composition contributes to the reduction of the refractive index by 2-11 %. It was found according to the BET method that the layers of the composition 75TiO2-20SiO2-5NiO (mol. %) on the surface of the fibreglass carrier were porous, the average pore size is equal to 3.3 nm. The total area of the specific surface area of the material increases from 0.3 to 2.5 m2/g. The resulting material shows activity in deep and partial oxidation of n -heptane. In a temperature range of 210-350 °C, the main products are ketones. At a temperature above 350 °C, a depth of oxidation increases, simultaneously, the yield of α-olefins is observed.
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