A review is presented of investigations devoted to the synthesis of nanopowders and films of titanium oxide for photocatalysis. The most frequently used methods for studying the composition and crystal structure of materials have been analyzed. The main results obtained in the field of the synthesis of TiO₂ nanopowders have been summarized. Most attention has been focused on the reactive sputtering methods and the influence of the composition and crystal structure of films on their photocatalytic properties. Additional heat treatment and doping of titanium oxide films serve as the main techniques for controlling their properties. It has been demonstrated that the formation of oxide film heterostructures makes it possible to significantly increase the catalytic activity of titanium oxide films.

Raman spectroscopy has been used to study the influence of partial oxygen pressure during deposition and isothermal treatment on the chemical composition of copper oxide films deposited by reactive...

A kinetic model of reactive sputtering is proposed to modify Berg’s model by taking into account the true chemical interaction at solid surfaces of the target, substrate, and chamber wall having different temperatures. Any chemical reaction is correctly characterized by the rate constant $k\left(T\right)$ rather than the sticking coefficient $\alpha$ , as it was previously done by Berg and other authors. Such a coefficient is solely inherent in the physical adsorption as an initial stage preceding the chemical interaction at the solid surfaces. Appropriate kinetic equations are derived by examining in detail the particle fluxes sputtered from the target and deposited onto the substrate and wall, as well as the surface chemical reactions. The kinetic equation for the target process has proved fully identical in form with that for the nonisothermal physical adsorption, whereas the kinetic equation for the substrate and wall processes are of a more complicated form. Analysis of the steady-state situation shows an advantage of the developed nonisothermal model over the isothermal Berg model for fitting to experimental data.

A rigorous and consistent approach is demonstrated to develop a model of the 4M structure (the four-media structure of a film on a substrate of finite thickness). The general equations obtained for the reflectance and transmittance spectra of the 4M structure are simplified by employing a procedure of the so-called device averaging to reduce them to a succinct form convenient for processing of experimental spectra for the structures with a thick substrate. The newly derived equations are applied to two special cases: (i) an arbitrary film on highly absorbing substrates and (ii) a slightly absorbing film on transparent substrates. The reflectance and transmittance spectra represented in the simplified (with the device averaging) form have a practical application for determining the film thickness and optical constants from experimental spectra by using the known techniques.