Carbon nanotubes/TiO2 nanotubes composite photocatalysts for efficient degradation of methyl orange dye

A series of carbon nanotubes/TiO₂ nanotubes (CNTs/TNTs) composite photocatalysts were successfully prepared by incorporation of CNTs in HNO₃ washing process. These photocatalysts were characterized by XRD, N₂ physical adsorption, UV–vis diffuse reflectance spectroscopy, TEM and Raman spectroscopy, respectively, and their photocatalytic activities were tested by using methy1 orange (MO) as a model compound. Also, the effects of amount of CNTs incorporated, calcination temperature and amount of catalyst on the photocatalytic activity of the composite photocatalyst were systematically investigated. The results show that the CNTs/TNTs composite exhibits much higher photocatalytic activity than that of the TNTs or CNTs alone.