Fabrication and photocatalytic performance of C, N, F-tridoped TiO2 nanotubes.

Graphical abstract C, N, F-tridoped TiO 2 nanotubes were prepared, exhibiting high photocatalytic activity for simulant wastewater under UV light and simulated sunlight. Highlights • C, N, F-tridoped TiO 2 nanotubes exhibited high photocatalytic activity. • Electronic transition was improved and band gap of TiO 2 was narrowed. • Synergy effect of the three dopants resulted in high activity. Abstract By impregnating the thermal stable TiO 2 nanotubes (C/TiO 2 NTs) in NH 4 F solution with different concentrations and subsequent calcination treatment at different temperatures, C, N, F-tridoped TiO 2 nanotubes (C, N, F/TiO 2 NTs) were prepared. XRD, XPS, TEM, TG-DTG, UV–vis and nitrogen adsorption were used to and characterize the prepared materials. The influences of dopants, calcination temperature and NH 4 F concentration on the catalytic performances of C, N, F/TiO 2 NTs under UV light and simulated sunlight were investigated by using methyl orange solution as simulant wastewater. Obtained results indicated that the C, N, F/TiO 2 NTs exhibited higher photocatalytic activity than the C-doped or N, F-codoped ones, and the C, N, F/TiO 2 NTs showed the best photocatalytic performance when they were calcinated at 300 °C and impregnated by 1 wt.% NH 4 F solution. The electronic density of states (DOS) analysis results implied that the C, N, F-tridoping could improve the electronic transition and narrow the band gap of anatase TiO 2 , and resulted in improved photocatalytic performance. The synergistic effects of the three dopants were also discussed. [ABSTRACT FROM AUTHOR]