Abstract

TiO2 anatase nanocrystals were surface modified by deposition of V(V) species. The starting amorphous TiO2 nanoparticles were prepared by hydrolytic processing of TiCl4-derived solutions. A V-containing solution, prepared from methanolysis of VCl4, was added to the TiO2 suspension before a solvothermal crystallization step in oleic acid. The resulting materials were characterized by X-ray diffraction, transmission electron microscopy (TEM), Fourier transform infrared, Raman, and magic angle spinning solid-state V-51 nuclear magnetic resonance spectroscopy (MAS NMR). It was shown that in the as-prepared nanocrystals V was deposited onto the surface, forming Ti-O-V bonds. After heat treatment at 400 degrees C, TEM/electron energy loss spectroscopy and MAS NMR showed that V was partially inserted in the anatase lattice, while the surface was covered with a denser V-O-V network. After heating at 500 degrees C, V2O5 phase separation occurred, further evidenced by thermal analyses. The 400 degrees C nanocrystals had a mean size of about 5 nm, proving the successful synthesis of the colloidal counterpart of the well-known TiO2-V2O5 catalytic system. Hence, and also due to the complete elimination of organic residuals, this sample was used for processing chemoresistive devices. Ethanol was used as a test gas, and the results showed the beneficial effect of the V surface modification of anatase, with a response improvement up to almost 2 orders of magnitude with respect to pure TiO2. Moreover, simple comparison of the temperature dependence of the response clearly evidenced the catalytic effect of V addition.

Autore Pugliese

• Epifani Mauro Salvatore , Siciliano Pietro Aleardo

Tutti gli autori

• Epifani M.; Diaz R.; Force C.; Comini E.; Andreu T.; Zamani R.R.; Arbiol J.; Siciliano P.; Faglia G.; Morante J.R.

Titolo volume/Rivista

Journal of physical chemistry. C

Anno di pubblicazione

2013

ISSN

1932-7447

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

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Numero di citazioni Scopus

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Settori ERC

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Codici ASJC

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