Synthesis and characterization of TiO2–montmorillonites doped with vanadium and/or carbon and their application for the photodegradation of sulphorhodamine B under UV–vis irradiation

TiO2–montmorillonite (MMT) photocatalysts doped with vanadium and/or carbon were successfully synthesized by a sol–gel method. It was novel that these photocatalysts had a high ratio of Ti/MMT, up to 120 mmol/g. For comparison, TiO2 photocatalysts doped with vanadium and/or carbon were also prepared by the same method without MMT. The as-prepared photocatalysts were characterized by XRD, BET, XPS, FTIR, UV–vis DRS and ICP. The vanadium and carbon species of the photocatalysts were detected by XPS, elemental analysis or FTIR. The absorption edge of TiO2–MMT was blue-shifted compared to TiO2 by UV–vis DRS. When a small amount of MMT was highly dispersed in the given TiO2 sol system, the silicate layers and the vacant d-orbits of the transition metal ions of MMT had obvious effects on the microstructure and the photo-catalytic activities of the MMT-containing photocatalysts. The degradation of aqueous sulphorhodamine B (SRB) on these photocatalysts was investigated under UV–vis irradiation.