Efficient photocatalytic removal of nitric oxide with hydrothermal synthesized Na0.5Bi0.5TiO3 nanotubes

In this study, Na0.5Bi0.5TiO3 nanotubes were synthesized with a facile hydrothermal method using TiO2 P25 (Degussa) and bismuth citrate (BiC5H6O7) as precursors in concentrated NaOH and ammonia alkali solution. The samples were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The as-prepared Na0.5Bi0.5TiO3 nanotubes exhibited superior activity for photocatalytic removal of gaseous nitric oxide (NO) over TiO2 P25 (Degussa) under simulated solar-light irradiation, the NO removal rate can reach as high as ca. 200 ppb center dot min-1 over the Na0.5Bi0.5TiO3 nanotubes in a continuous reactor with an initial NO concentration of 400 ppb. The intrinsic hollow-nanotube structure of the Na0.5Bi0.5TiO3 photocatalysts contributes to its superior activity under simulated solar light. This work provides a facile route to prepare Na0.5Bi0.5TiO3 nanotubes and suggests that the Na0.5Bi0.5TiO3 nanotubes are ideal candidates for efficient removal of nitric oxide in indoor/outdoor air. (C) 2014 Elsevier B.V. All rights reserved.