Facile fabrication of N-doped TiO2 nanocatalyst with superior performance under visible light irradiation

A facile and convenient method has been developed to prepare N-doped TiO2 visible light nanocatalysts, which is performed by a solid-state calcination of one-dimensional titanate nanotubes with an inorganic ammonium salt (NH4Cl). The ion-exchange reaction between layered nanotubes and NH4Cl contributes to the phase transition to crystalline TiO2 combined with N doping. X-ray diffraction and transmission electron microscopy are carried out to study the phase evolution, compositions, and morphologies of obtained samples. X-ray photoelectron spectroscopy reveals that the N dopant in TiO2 is assigned to the interstitial NHx species. Both the phase transition and N doping are further confirmed by UV–vis diffuse reflectance spectra. All N-doped TiO2 materials exhibit significantly higher visible light activities than that of the parent nanotubes for degrading rhodamine B. In addition, the N-doped TiO2 nanocatalyst holds a strong stability and durability for the removal of organic pollutions.

Graphical abstractSolid-state calcining of titanate nanotube with NH4Cl leads to the formation of N-doped TiO2 nanocatalyst, which shows an enhanced photocatalytic activity under visible light. Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► N-doped TiO2 catalyst is synthesized by a facile and environment-conscious method. ► An inorganic ammonium salt and titanate nanotubes were used as Ti and N sources. ► A low temperature formation of anatase–rutile heterojunctions has been achieved. ► The nanocatalyst shows an enhanced spectral absorption in visible light region. ► The catalyst owns a high ability for the visible light induced degradation of dye.