In Situ Growth and Structure Characterization of V 2 O 5 /tio 2 Coatings on Multiwalled Carbon Nanotubes

Uniform and continuous V 2 O 5 and/or TiO 2 coatings on multiwalled carbon nanotubes (V 2 O 5 /TiO 2 -MWCNTs) were prepared by a molten salt method combined with a subsequent oxidation process. VC/TiC coatings were first deposited onto the MWCNTs by molten salt reaction and subsequently transformed in situ into V 2 O 5 /TiO 2 with thickness of about 12 nm. The results showed that the composition, structure, and visible-light photocatalytic activity of the composites largely depended on the molar concentration of vanadium. Incorporation of vanadium significantly changed the chemical states of the photocatalyst surface and increased the hydroxyl groups and Ti 3+ and Ti 2+ ions. Both V 5+ and V 4+ were present in the structure. The V 2 O 5 /TiO 2 -MWCNTs composites showed higher removal rate and photodegradation rate for methylene blue than TiO 2 -MWCNTs.