RESUMEN
Nanocomposites of TiO2 and multi-walled carbon nanotubes (MWNTs) were produced by the addition of different concentrations of MWNTs to a TiO2 sol matrix. Conductive coatings were prepared by spin coating the nanocomposite sols on glass substrates and sintering the samples at 300 degrees C for 15 min. No crystalline phase of TiO2 was formed at this temperature. The sheet resistance of the coatings was decreased from some hundreds of Momega/sq to just a few komega/sq by the addition of MWNTs to the TiO2 matrix. Moreover, sintering of the coatings in a reducing atmosphere has lead to a lower sheet resistance than that presented by coatings sintered in air. The lowest resistivity of 2.0 x 10(-1) omega x cm was obtained by coatings prepared with 5.0 mg/ml MWNTs in the composite sol. The optical, structural and electrical properties of the coatings were correlated and demonstrated.
RESUMEN
Nanocomposites of titanium dioxide (TiO(2)) and multi-walled carbon nanotubes (MWNTs) were prepared and deposited by sol-gel spin coating on borosilicate substrates and sintered in air at 300 °C for 15 min. Further irradiation of the films with different CO(2) laser intensities (4.3-17 W m(-2)) was carried out in order to crystallize TiO(2) in the anatase form while preserving the MWNT's structure. The laser irradiation changed the crystal structure of the coatings and also affected the wettability and photocatalytic activity of the films. The anatase phase was only observed when a minimum laser intensity of 12.5 W m(-2) was used. The contact angle decreased with the enhancement of the laser intensity. The photocatalytic activity of the films was determined from the degradation of a stearic acid layer deposited on the films. It was observed that the addition of carbon nanotubes themselves increases the photocatalytic activity of TiO(2) films. This efficiency is even improved when high CO(2) laser intensities are used during the sintering of the coatings.