Visible-light-driven NaTaO3−N catalyst prepared by a hydrothermal process

Abstract NaTaO 3− x N x catalyst has been successfully synthesized from N-doped Ta 2 O 5 precursors by a simple hydrothermal process. The as-prepared samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy. Density functional theory calculations suggested that the valence band of the catalysts was composed of the hybrid O 2p and N 2p orbitals, and the visible-light sensitivity is due to the narrowing of the band gap by mixing N 2p and O 2p states. NaTaO 3− x N x catalyst could decompose the gaseous formaldehyde under the visible-light irradiation ( λ > 400 nm), and its photocatalytic activity depended on N dopant concentration. NaTaO 2.943 N 0.047 showed the highest photoactivity for the formaldehyde photodegradation.