New and cost effective solar light photocatalysis of MOCVD
nanostructured titania films for ecological applications
Titania (TiO2) nanostructured thin films have been synthesized in our
institute by the MOCVD technique. This technique has offered the relevant
peculiarity of depositing titania in the anatase phase with a calibrated
oxygen deficiency; the films were so characterized by intermediate
states in the band gap allowing the interaction with the visible light.
Our recent results put a milestone regarding the solar light
photocatalis.
Indeed titania ceramics in the anatase crystalline form are far
recognized as excellent, environmentally friendly, and relatively
inexpensive photocatalysts, especially used for organic decontamination in
water and air, decomposition of bacteria, and reduction of heavy metals
ions in industrial waste streams; however, the wide use of this
photocatalyst has been largely hindered till now by the fact that the
ultraviolet light required for its activation, constitutes only three
percent of sunlight.
The first result of our research was the fabrication of oxide titanium
with higher photoconversion efficiency in the visible spectral range,
e.g. the ratio of photoconversion efficiencies in the visible (400-780 nm)
with respect to UV (280-400 nm) radiation, at the same irradiation power,
resulted about 15%, while for any commercially available titanium oxide
this ratio is practically zero. More exciting results are awaited for the
immediate future. Moreover a process that can remove metals and destroy
organics at the same time would represent a significant breakthrough for
the treatment of contaminated waters by using solar irradiation.
The research resulted from a high collaboration among European teams. The
research core has been started by CSIC in Barcelona and our institute.
The preliminary results have been published in the review Advanced
Materials (about 6 impact factor). A STREP project will be presented to
European Community involving 8 labs (2 Italians, 2 Spanish, 1 French, 1
Belgian, 1 Slovak , 1 Mexican), 1 French factory and 1 Slovak factory.
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