Spectroscopy studies of TiO2/carbon nanotubes nanocomposite layers synthesized by the sol-gel method

Abstract

Titanium dioxide in the form of anatase is known to be a good photocatalyser but catalytic properties strongly depend on TiO2 grain size, morphology and surface area of thin film. The aim of this study was to evaluate influence of carbon nanotube additive on photocatalitic properties of TiO2.Titanium dioxide/multiwalled carbon nanotubes (MWCNT) nanocomposites were prepared by sol-gel method in the form of a thin layer on glass substrates. Samples were characterized by X-ray diffraction (XRD) and Grazing Incidence Diffraction (GID), Raman, FTIR and UV-VIS spectroscopy, as well as scanning electron microscopy (SEM). The photocatalytic activity of prepared films was evaluated by the detection of changes in the UV-VIS spectra after the discoloration of Reactive Black V pigment - water solution. It was found that the crystalline TiO2 is composed of anatase phase only. Presence of MWCNTs in the composite increases the size of TiO2 particles. Additive of nanotubes into the TiO2 resulted in an increase in photocatalytic activity in both the UV and visible range by 10 and 50% respectively compare to undoped TiO2. Furthermore, carbon nanotubes lead to better dye adsorption on the surface. Additionally significant reduction in the contact angle, approximately 50% (compare to pure TiO2) was also observed. The obtained results suggest that the TiO2/carbon nanotubes composite material can be activated by light from visible range.