Nanocomposites and nanomaterials

The synthesis of nanosized TiO2/SnO2 composition by ultrasonic method
Sachuk O.V., Zazhigalov V.A., Diyuk O.A. 
Department of Heterogeneous Catalytic Oxidation Processes, Institute for Sorption and Problems of Endoecology of the NAS of Ukraine. General Naumov str., 13, Kyiv-03164, Ukraine. 
E-mail: Slena951@ukr.net 

The oxides of tin and titan and compositions based on them are widely use as gas sensors, electrodes, functional composition materials, catalysts et al. The most of traditional methods of Ti-Sn-O compositions preparation such as sol-gel, precipitation, thermal decomposition do not allow to synthesize high dispersed products as nanopowders. So, the sonochemical treatment is an alternative and simple method for complex nanocomposites obtaining.
The ultrasonic treatment (UST) of TiО2-SnO2=1:1 sample was conducted in dispergator UZDN-2Т in water solution during 2 hs.
According to XRD it was found that the decrease in intensity of basic reflexes occurs as a result of decrease of average particle size (from 60 to 50 nm) and change of dominant reflex of phase SnO2  – from the reflex [101] to reflex from the plane [110] that is due to oxide anisotropic deformation.
 FT-IR data show that the slight shift of absorption band ν Sn-О bond from 536 to 522 сm-1 and decrease in intensity of band Sn-O-Sn bond at 613 cm-1 as a result of anisotropic deformation of SnO2 is observed. 
The study of TiO2/SnO2 composition by DTA-TG method shows two endothermic effects on the DTA-curve with maximums at 70 and 372°С, respectively. The first of them can be connected with desorption water and tinic acid SnO2·хH2O formation. The presence of the second endoeffect can be explained by decomposition of tin hydroxide, the formation of which likely connected with treatment conditions. 
Adsorption studies of the samples by BET-method show that sonoactivation leads to insignificant increase of specific surface area (from 2 to 4 m2/g).
Data obtained by TEM method show the uniformity and spherical primary particles (crystal size of dioxide tin 60 nm coincides with values obtained by Scherrer formula).