Nanocomposites and nanomaterials

Structural, optical and photocatalytic properties of La/TiO2 nanocomposites 
Shapovalova M.V.1, Khalyavka T.A.1, Manuilov E.V.2, Shymanovska V.V.2, Shcherban N.D.3, Permyakov V.V.4  
1Institute for Sorption and Problems of Endoecology NAS of Ukraine, General Naumov str., 13, Kyiv, Ukraine, 03164 E-mail: bondarenko_maryna@ukr.net 
2Institute of Physics NAS of Ukraine, 46 Nauki Ave., Kyiv, Ukraine, 03028
3 L.V. Pisarzhevskii Institute of Physical Chemistry NAS of Ukraine, Prospekt Nauky, 31, Kyiv, Ukraine, 03028.
4Institute of Geological Sciences NAS of Ukraine, O. Gonchar Str., 55-b, Kyiv, Ukraine, 01054

Titanium dioxide is known to be used widely as a photocatalyst. Nowadays researchers paid attention to employing techniques of TiO2 doping with different elements [1]. La/TiO2 nanocomposites were synthesised via sol-gel method. Structures, morphologies and photocatalytic activities of the nanocomposites were determined using X-ray diffraction, scanning electron microscopy, energy-dispersive spectrometry, transmission electron microscopy, nitrogen adsorption-desorption, UV-vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The photocatalytic activities of the nanocomposites were evaluated for the degradation of the model pollutants (Safranine T, Rodamine B). 
Nanocomposites consist of the aggregates of ca.10-12 nm size crystallites. Diffractograms of samples show peaks, which belongs to anatase and rutile phases. Analysis of nitrogen adsorption–desorption isotherms for the synthesized nanocomposites showed the presence of a hysteresis loop which is the evidence for mesoporous structure of the powders. The specific surfaces of the modified samples were twice as large as those of pure titanium dioxide.
Nanocomposites showed higher photocatalytic activity compared to pure TiO2. The values of photocatalytic activity constants correlate with those of sorption for the corresponding substrates, indicating that the substrate molecules sorbed on the catalyst surface were first subjected to photocatalytic transformation.  

1.	Kumar A., Pandey G. Preparation and Photocatalytic Activity of Co: La: TiO2 Nanocomposites for the Degradation of Methyl Blue in Visible Light // JOJ Material Sci.-2017.-2, N 5.-P. 55559.