Coupling titania nanotubes and carbon nanotubes to create photocatalytic nanocomposites

A titania nanotube/single-wall carbon nanotube composite was prepared by a simple hydration dehydration process. These composites were characterized using X-ray diffraction and spectroscopic techniques (UV-visible diffuse reflectance, Raman, photoluminescence, and EPR) as well as electron microscopy (SEM, TEM). SEM and TEM images indicated that single-wall carbon nanotubes (SWCNTs) were interwoven with the titania nanotubes. Raman spectra further confirmed the chemical interaction between the titania nanotube and the SWCNT in the composites. The photoactivity of these composites was tested by the photooxidation of acetaldehyde. The composites showed enhanced photoactivity under both visible and UV light in comparison with conventional titania (P25) and controls. The composite having a mass ratio of 1:50 (SWCNT/TiNT) showed the maximum photocatalytic activity for acetaldehyde decay under visible light. XPS and EPR spectra indicated the creation of Ti-O-C bonds between the titania nanotube and the SWCNTs during the hydration dehydration process, which explains the visible light photoactivity.