Photodegradation of methyl orange by photocatalyst of CNTs/P-TiO₂ under UV and visible-light irradiation

A novel nanoscale photocatalyst CNTs/P-TiO₂ was successfully prepared by hydrothermal method. The morphology and the physicochemical properties of the prepared samples were investigated using TEM, XPS, XRD, BET, FTIR, TG-DSC and UV–vis DRS spectroscopy. The photocatalytic activity was evaluated by degradation of methyl orange (MO) dye. The results demonstrated that CNTs/P-TiO₂ nanoparticles could effectively photodegrade MO not only under UV irradiation but also under visible-light (VL) irradiation. The MO degradation performance on CNTs/P-TiO₂ was superior to that of the commercial P25. The optimal mass ratio of CNTs to P-TiO₂ in the nanocomposite catalyst was 5:100. The synergetic effect was discussed in terms of different roles played by phosphorus doping and introducing CNTs into the composite catalysts.