Excellent visible light-driven photocatalytic performance and band alignment of g-C3N4/TiO2 nanotube heterostructures

Visible-light-driven graphite-like carbon nitride/TiO2 nanotubes (g-C3N4/TNTs) heterostructures were synthesized by hydrothermal and calcination processes. The g-C3N4/TNTs heterostructures with the different weight ratios of g-C3N4 to TNTs, from 0.5 wt% to 5 wt%, were characterized by modern methods of physical-chemical analysis. The photocatalytic activity of materials was evaluated by the degradation of methylene blue (MB) dye in aqueous under the visible light. Results showed that the MB photocatalytic degradation performance of the g-C3N4/TNTs heterostructures was enhanced, and that of the 2% g-C3N4/TNTs witnessed the highest efficiency (81%, 180 min). The photocatalytic activity was improved, thanks to the extended optical absorption range and enhanced separation of the photoinduced electron-hole pairs. Furthermore, the band alignment of the g-C3N4/TNTs heterostructures was determined by the preliminary calculation.