Nitrogen doped titania plates with dominant {0 0 1} facets: Microstructure and property evolution, and their photocatalytic activities

Nitrogen doped TiO₂ plates with dominant {0 0 1} facets were successfully synthesized by one-pot hydrothermal method. The dependence of microstructure and property evolution, such as crystal phase, morphology, N-doping and optical response property, on the hydrothermal time was investigated systematically, and their photocatalytic activities for the degradation of methylene blue are evaluated under visible light irradiation. The results showed that the structure of cubic TiN with the morphology of irregular bulk gradually collapses to form the structure of anatase TiO₂ with the morphology of well-defined plate during the hydrothermal process with the extension of hydrothermal time. The bonds of TiN in TiN are gradually replaced by OTiN and TiON due to the oxidation effect, which realizes the N-doping of TiO₂ plates. The as-prepared N-doped TiO₂ plates with dominant {0 0 1} facets demonstrate photocatalytic activity under visible light irradiation (λ > 420 nm), and their photocatalytic activities are decided by the synergistic effects of many factors, such as crystal phase, morphology, nitrogen doping, optical response, in which morphology and nitrogen doping are more significant factors in comparison with crystal phase and optical response.