Improving the photocatalytic activity of nitrogen-doped surface defect TiO2-x nanobelts for degradation of organic pollutants

Abstract

The synthesis of surface defect TiO2-x nanobelts with excellent visible light absorption is important to reduce costs, increase stability, and improve photocatalytic activity. In this work, we report that nitrogen-doped surface defect TiO2-x nanobelts are synthesized by annealing pristine TiO2 nanobelts in Ar/H2 (95%/5%) atmosphere followed by subsequent heat treatment in NH3 at various temperatures. The aim is to study the effect of the extent of the N-doping amount in the lattice of TiO2-x nanobelts on light absorption and photocatalytic activity. Considering the increase in organic pollutants in wastewater, the photocatalytic activity is measured by degrading rhodamine B (RhB) dye in water. The results demonstrate that the calcination temperature affects the doping level of N, and the b-TiO2-N550 sample exhibits higher photocatalytic performance than that of other samples under visible-light irradiation for the degradation of rhodamine B, which is up to 96.11%. The enhancement is ascribed to the synergistic effect of N-doping and self-doping oxygen vacancy (which extend the visible light absorption) and the separation efficiency of photogenerated carriers, which improves the photocatalytic activity.