Enhanced removal of acid orange II from aqueous solution by V and N co-doping TiO-MWCNTs/γ-AlO composite photocatalyst induced by pulsed discharge plasma.

This paper presents a study of V and N co-doping TiO embedding multi-walled carbon nanotubes (MWCNTs) supported on γ-AlO pellet (V/N-TiO-MWCNTs/γ-AlO) composite photocatalyst induced by pulsed discharge plasma to enhance the removal of acid orange II (AO7) from aqueous solution. The photocatalytic activity of the V/N-TiO-MWCNTs/γ-AlO composite to AO7 removal induced by the pulsed discharge plasma was evaluated. The results indicate that the V/N-TiO-MWCNTs/γ-AlO composite possesses enhanced photocatalytic activity that facilitates the removal of AO7 compared with the TiO-MWCNTs/γ-AlO and TiO/γ-AlO composites. Almost 100% of AO7 is removed after 10 min under optimal conditions. The V/N-TiO-MWCNTs/γ-AlO photocatalyst exhibits the best removal effect for AO7. Analysis of the removal mechanism indicates that the enhancement of the removal of AO7 resulting from V and N co-doping causes TiO lattice distortion and introduces a new impurity energy level, which not only reduces the band gap of TiO but also inhibits the recombination of the e/h pairs.