Nanocomposites and nanomaterials 

Improving the photocatalytic properties of tin dioxide by doped with titanium and copper.
Samsonenko M.M.1, Khalameida S.V.1, Sydorchuk V.V.1, Zakutevskyy O.I.1, Starchevskyy V.L.2, Lakhnik A.M.3
1 Institute for Sorption and Problems of Endoecology of NAS of Ukraine, 13 Naumov Str., Kyiv 03164, Ukraine.
E-mail: email.of. corresponding_author@server.com
2 Institute of Chemistry and Chemical Technologies, L’viv National Polytechnic University, 12, S.Bandera Str, 79013, L’viv, Ukraine.
3 G. V. Kurdyumov Institute for Metal Physics, N.A.S. of Ukraine, 36, Academician Vernadsky Blvd., 03142, Kyiv, Ukraine

One of the ways to improve the photocatalytic activity of tin dioxide in the processes of neutralization of organic pollutants in aqueous solutions is the doping with transition metals. At doping with titanium dioxide, there is observed the formation of mutual solid solutions. Copper monoxide is a p-type semiconductor, therefore when used as a tin dioxide dopant, the formation of “p-n heterojunction transition” is possible. Thus, it is interesting to investigation of the effect of doping of tin dioxide with titanium and copper on the physical-chemical, especially electronic properties of the obtained samples and, as a result - on their activity in photodergadation of pollutants in water. We doped the precipitated and comercial SnO2 by mechanochemical (MChT) and ultrasonic treatment (UST). As an additive, TiO(OH)2 and Cu2O was used in an amount of 5 and 10 wt. % based on oxides. Doped with titanium samples were subjected to thermal treatment (TT) in air at 300 and 550ºC. It was found that at doping of SnO2 and next TT there are no reflexes of the TiO2 phase on diffractograms and there is a decrease in the lattice parameters a and c. This may be evidence of solid solution formation. All doped precipitated and commercial SnO2 samples are characterized an increase in the specific surface area and total pore volume, and following thermal treatment assist to reduce the specific surface area and micropores volume. The formation of meso-macroporous structure of doped and calcined samples is observed. In addition, for doped samples there are a decrease in the band gap Eg and an increase in visible light absorption of up to 50%. For example, the band gap for the initial precipitated sample is 4.2 eV, and for SnO2 doped with titanium and after TT at 550° C - 2.7 eV. Doping of tin dioxide with titanium and copper increases the photocatalytic activity under the action of visible light in several times.