Nanocomposites and nanomaterials

Controlled sol-gel synthesis and photocatalytic activity of C-doped TiO2 nanostructures
Romanovska N.I.1, Manoryk P.A.1
1 Physico-inorganic chemistry Department, L.V. Pysarzhevskii Institute of Physical Chemistry of the NAS of Ukraine. Prospect Nauki, 31, Kyiv-03039, Ukraine. 
E-mail: nat.romanovska@gmail.com

Synthesis of nanomaterials with controlled size, morphology, phase composition, texture is one of the main problem in modern materials science. One of the most suitable ways to resolve this problems is sol-gel method. Controlling of hydrolysis and condensation rate by using acidic catalysis provide forming of materials with special physico-chemical properties. Investigation of TiO2 nanostructures, obtained by sol-gel method, as photocatalysts develop new ways of environmental technologies. Controlled sol-gel synthesis of TiO2 nanostructures is more perspective field of scientific and ecological interests. 
The aim of this work was to develop a simple way of controlling sol-gel synthesis TiO2 nanostructures and investigation of the influence of catalysts amount on the anatase phase content, particles size and shape,  crystallinity, texture and photocatalytic activity of obtained materials in photodegradation of tetracycline (TC).
The C-doped TiO2 nanostructures were obtained by controlled sol-gel method with variation of catalysts amount with next solvothermal treatment and calcinating. As indicated by XRD results, the anatase phase content and crystallite size of nanostructures decrease with catalysts amount increasing. The morphology of C-doped TiO2 transformed from spheroidal to sheet-like together with catalysts amount increasing. The photocatalytic activity of obtained nanostructures was investigated in TC photodegradation reaction under UV- and visible light irradiation. It was shown, that conversion degree of TC during 30 min was extremely dependent on catalysts concentration in the initial reaction mixture and more than 2 higher (UV) and 1.8 higher (Vis) than P-25 Evonik. Visible light photocatalytic activity of C-doped TiO2 may be induced by the interstitial Ti-O-C. 
The spheroidal nanostructures C-doped TiO2 , which were obtained, provides effective solar light harvesting and may be used as photocatalysts for tetracycline and other antibiotics photodegradation processes at solar light irradiation.