Ta doped nanostructured TiO2 for liquid phase photodegradation reactions

Titanium dioxide has been widely studied as a photocatalyst. One of the main applications lies in the environmental remediation, both in gas and liquid phases. Especially, degradation of VOCs has been investigated. In more recent years, research in this field has been focused on the detection and the degradation of new emergent pollutants, such as pharmaceutical compounds and their metabolites. Moreover, structural properties of titanium dioxide deeply influence its photocatalytic performance. It is well-known in the literature that among the three natural crystalline phases (anatase, brookite and rutile) anatase is the most promising for this application, thanks to the more favourable position of its conduction band, even if its band gap is larger (3.2 eV) than those of brookite and rutile (3.0 eV). Nonetheless, the compresence of two different crystalline phases can be very useful, promoting the trapping of the photogenerated electrons from one to the other, lowering the possibilities of electronhole recombination. Moreover, doping with transition metals is widely used to promote TiO2 photocatalytic activity under UV light. In particular, theoretical results have forecast tantalum as efficient dopant of TiO2 for UV photodegradation, thanks to the electronic states generated in the conduction band. Here, pristine and Ta doped TiO2 nanomaterials were prepared, characterized and photocatalytically tested in three different degradation reaction, both in gas and liquid phase.