Preparation, characterization and photocatalytic activity of N-doped NaTaO3 nanocubes

The N-doped NaTaO₃ catalysts with cubic morphology had been successfully synthesized by one-step hydrothermal method, using Ta₂O₅ and NH₃·H₂O as the raw materials for the first time. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectra. The results showed that the synthesis parameters such as reaction temperature and reaction time played important roles in the formation of N-doped NaTaO₃ nanocubes. As observed by SEM images, when the reaction time reached 12 h, most of the products exhibited the square morphology with the size of 200-500 nm, which can be easily removed by filtration after photocatalytic reaction. The photocatalytic activity of N-doped NaTaO₃ was tested by Methylene Blue degradation process under ultraviolet and visible light irradiation, respectively. The results showed that both under the ultraviolet and visible light irradiation, N-doped NaTaO₃ displayed much higher photocatalytic activity than that of pure NaTaO₃. In addition, NaTaO_3-xN_x composites exhibited excellent stability in the visible-light photocatalytic process.