Enhanced UV-Detection and Photocatalytic Performance of TiO2-SWNTs Nanocomposite Fabricated by Facile Wetness-Impregnation Method

Nanocomposites of anatase titania/SWNTs were fabricated by facile and template free continuous ultrasonication/stirring of precursors in ethanol under high power UV illumination. TEM micrographs showed that the TiO2 nanoparticles (NPs) were uniformly dispersed on the SWNTs walls. The XRD and FTIR spectra revealed the coexistence of precursors in the fabricated nanocomposites. The enhanced photocatalytic properties of the nanocomposites as well as the broad peak of the FTIR at vibrational bands around 500-700 cm(-1) (due to Ti-O and Ti-O-C) suggest that an O-Ti-C heterojunction is probably formed under UV illumination during the synthesis procedure. The photocatalytic activity of the nanocomposites was measured by decolorization of the organic pollutant methylene blue (MB). The results proved that the degradation kinetic constant of the nanocomposite containing 10 wt.% SWNTs was 1.55 times more effective than virgin TiO2 NPs under the same experimental conditions. The UV-detection performance results showed that the composite photodetectors not only possessed a desirable UV photosensitivity, but also the response time of the composite thin film (containing 10 wt.% SWNTs) was decreased compared to pure TiO2 powder. Both UV-assisted properties are generally dependent on the inhibition of electron/hole recombination.