Performances of La-TiO2 nanoparticles as gas sensing material

Nanosized La-TiO2 has been prepared by sol-gel and analyzed by TEM, XPS, ICP and XRD characterization techniques. The various techniques highlighted that La retarded the anatase-to-rutile transformation, hindered the grain growth and created Ti3+ after calcinations at 900 °C. Lanthanum was segregated as La4Ti9O24 in an inner surface layer when the formation of rutile occurred. XPS measurement showed an enrichment of the surface of the particles with La atoms and manifested the presence of La2O3. The gas test showed that the incorporation of 10 at.% of La resulted in a specially positive approach to a more selective ethanol sensor. The detection of alcohols aroused particular interest, since the materials calcined at high temperatures, i.e. 900 °C, showed a response to ethanol enhanced and quickened. Besides, this came along with the spoiling of the performances for CO detection.