"Nanocomposites and nanomaterials"

The study of physical and chemical properties of mechanotreated TiO2/Nb2O5=1:1 composition
Sachuk O.V., Zazhigalov V.A., Kuznetsova L.S., Kiziun O.V., L.Yo. Kotynska 
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 
Materials based on titanium and niobium oxides are very interesting for several application, namely solar cells, photocatalysts, in the fiber optic amplifier, and fiber laser application. The synthesis of such materials by mechanochemical method of treatment (MChT) gives a possibility to obtain TiO2 and NbO2-containing compositions with excellent physical and chemical properties.
The complex binary oxide TiO2/Nb2O5=1:1 composition was mechanochemically treated for 4 hours in air medium. 
XRD data show that MChT of oxide titanium/niobium mixture leads to anisotropic deformation of orthorhombic phase Nb2O5 and decrease of particle size from 50 nm up to 10 nm. It was found that as a result of mechanochemical activation the increase of specific surface area of the sample (from 4 m2/g to 11 m2/g) with formation of mesoporous structure is carried out. 
Due to SEM investigations (Fig. 1) it was found that TiO2/Nb2O5=1:1 sample after activation has nanocrystalline structure and the fact of particle size decrease is confirmed. 
		
a	b	
Fig.1. SEM images of TiO2/Nb2O5=1:1 samples: a – initial, b – after MChT 

According to TG-DTA data the appearance of exothermic peak at 530°C in the DTA-curve of mechanically milled powder which is assigned to transition of Nb2O5 from amorphous state to crystalline one was observed.