Ultrasonic-assisted of TiO2-MWCNT nanocomposite with advanced photocatalytic efficiency for elimination of dye pollutions

Nanocomposites of titanium dioxide (TiO2) and multi-wall carbon nanotubes (MWCNTs) were successfully synthesized (TiO2-MWCNTs) from MWCNTs and titanium tetrachloride (TiCl4) as starting precursors using ultrasonic-assisted technique. The impact of the different weight percentages of MWCNTs (1, 3, 5, and 7 wt%) on TiO2 optical, structural, and morphological properties were investigated. Subsequently, the photocatalytic activity was assessed by organic dyes degradation such as methylene Blue (MB) and rhodamine B (RhB) under ultraviolet (UV) light exposure. The characterization of synthesized materials demonstrated the anatase phase formation in both pure TiO2 and the TiO2-MWCNTs nanocomposite, according to X-ray diffraction analysis. The morphology analysis of TiO2-MWCNTs nanocomposites using FESEM and TEM confirmed the uniform dispersion of MWCNTs with an exterior diameter of 12–16 nm within the TiO2 matrix. The BET measurement of the sample's specific surface areas identified that the MWCNTs addition resulted in the increase of surface area from 76.34 to 194.35 m2 g−1 for pure TiO2 and TiO2/7 wt% MWCNTs, respectively. Furthermore, TiO2/7 wt% MWCNTs nanocomposite had lower optical bandgap energy and higher photocatalytic performance as compared to the pure TiO2. The photodegradation efficiency of TiO2/7 wt% MWCNTs nanocomposite increased from 63.63 % to 92.36 % for MB and 71.56 % to 94.13 % for RhB compared to pure TiO2, after 60 min UV light exposure.