N-doping TiO2 thin film prepared by heat treatment in electric field

A visible-light-active TiO2−xNx photocatalyst was synthesized in electric field. The N-doping TiO2 film had a thickness of about 70–80 nm. The results of the photocatalytic experiments showed that the vis-activity rose largely. XPS and XRD analysis implied that the doping N substituted the oxygen-deficient in TiO2 film. The Einstein shift in optical absorption spectrum of the N-doped film was also observed by the UV–VIS with a cut wave length of about 550 nm. Based on the experiment, it could be concluded that the N doping is effective to narrow the gap and enhance the photocatalysis.