Synthesis of carbon nanotube/anatase titania composites by a combination of sol–gel and self-assembly at low temperature

A simple method is described for the synthesis of carbon nanotube/anatase titania composites by a combination of a sol–gel method with a self-assembly technique at 65 °C. This method makes use of polyelectrolyte for wrapping multi-walled carbon nanotube (MWCNT) and providing them with adsorption sites for electrostatically driven TiO2 nanoparticle deposition. The composites were characterized using X-ray diffraction, transmission electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy, and photoluminescence for analyzing their crystal phase, microstructure, particle size, and other physicochemical properties. The results showed that MWCNT were covered with an anatase TiO2 thin layer or surrounded by an anatase TiO2 thick coating, which is constructed of TiO2 particles about 6 nm in size. The composites were rich in surface hydroxyl groups. The excited e− in conduction band of TiO2 may migrate to MWCNT. Concerning the potential applicability, MWCNT/TiO2 composites showed excellent photocatalytic activity toward the photodegradation of methyl orange.