Open Access Research article

Hydrogen peroxide route to Sn-doped titania photocatalysts

Václav Štengl12*, Tomáš Matys Grygar12, Jiří Henych12 and Martin Kormunda3

Author Affiliations

1 Department of Solid State Chemistry and Analytical Laboratory, Institute of Inorganic Chemistry AS CR v.v.i., 250 68, Řež, Czech Republic

2 Faculty of the Environment, J.E. Purkyně University, Králova Výšina 7, 400 96, Ústí nad Labem, Czech Republic

3 Department of Physics, Faculty of Science, J.E. Purkyně University, České mládeže 8, 400 96, Ústí nad Labem, Czech Republic

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Chemistry Central Journal 2012, 6:113  doi:10.1186/1752-153X-6-113

Published: 5 October 2012

Abstract

Background

The work aims at improving photocatalytic activity of titania under Vis light irradiation using modification by Sn ions and an original, simple synthesis method. Tin-doped titania catalysts were prepared by thermal hydrolysis of aqueous solutions of titanium peroxo-complexes in the presence of SnCl4 or SnCl2 using an original, proprietary "one pot" synthesis not employing organic solvents, metallo-organic precursors, autoclave aging nor post-synthesis calcination. The products were characterized in details by powder diffraction, XPS, UV–vis, IR, and Raman spectroscopies, electron microscopy and surface area and porosity measurements

Results

The presence of tin in synthesis mixtures favors the formation of rutile and brookite at the expense of anatase, decreases the particle size of all formed titania polymorphs, and extends light absorption of titania to visible light region >400 nm by both red shift of the absorption edge and introduction of new chromophores. The photocatalytic activity of titania under UV irradiation and >400 nm light was tested by decomposition kinetics of Orange II dye in aqueous solution

Conclusions

Doping by Sn improves titania photoactivity under UV light and affords considerable photoactivity under >400 nm light due to increased specific surface area and a phase heterogeneity of the Sn-doped titania powders.

Keywords:
TiO2; Sn doping; Wet synthesis; Vis light; Photocatalysis