Over the past ۱۵ years or so, structural and compositional architecture of
core-shell materials has received significant research attention, because of their importance to the development of nanotechnology in the areas of energy storage systems, drug delivery carriers, composite catalysts, photonic crystals, plasmonics derives, magnetic imaging agents, low κ-dielectrics, chemical and optical sensors, and protected functional materials. There are certain problems associated with nanometric TiO۲, which make practical applications difficult and costly. Such problems include nanoparticles’ agglomeration [۱], phase transformation, decrease in surface area upon thermal treatment [۲], recombination of photogenerated electron-hole pair, lack of visible light photoactivity due to its wide band gap ( Eg = ۳.۲ eV) [۳]. The difficulty in recovery of the nanocatalyst from aqueous suspension.To solve most of these problems, titania and other functional metals/metal oxides nanoparticles can be coated in the form of a layer on the surface of thermally stable, low cost and high surface area core materials such as SiO۲,ZrO۲, MoO۳ and Fe۲O۳ [۴]. Silica is one of the best core materials [۵] for preparing the CSNs due to its rich and well-known surface chemistry and adsorption capacity, easy and controllable preparation by the Stöber method [۶], optical transparency in the wavelength region where TiO۲ absorbs, low cost and high thermal and mechanical stability. Another advantage of using SiO۲ as the core material is that it is easier to separate it from the core@shell structure with an alkaline solution. The core@shell configuration generally results in improved material properties and the physical and chemical properties of CSNs can be tuned by controlling the morphology and thickness of the shell [۷] or the size of the support material. In this research, the
core-shell synthesis of silicon dioxide (SiO۲) and
titanium dioxide (TiO۲) [silica core] was carried out. For this purpose,
silica powder and isopropanol were mixed with different amounts of titanium butoxide, (Ti (BuO) ۴) washed and dried. When the ratio of SiO۲ and TiO۲ was ۱:۲, the amount of free TiO۲ increased and the amount of formed shell-thickness decreased. When the ratio of TiO۲ and SiO۲ was ۱:۲,the amount of received shell-thickness increased. However, in both syntheses,
core-shell SiO۲-TiO۲ was formed.In the continuation of the research, polyaniline/SiO۲@TiO۲ composite will formed by electrochemical method to prevent the
corrosion of soft carbon steel.