Enhanced Photocatalytic Activity of Perovskite-Type NaTaO3 by Effective Nitrogen Doping

N-doped perovskite-type NaTaO3 with cubic shape was synthesized by a facile hydrothermal method and nitridation treatment in the presence of ambient NH3. The well-crystalline N-doped NaTaO3 (N-NaTaO3 products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (SEM) and ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS). The photocatalytic activity of N-NaTaO3 was evaluated by decomposing Rhodamine B (RhB) under UV-light irradiation. The results revealed that the as-treated NaTaO3 possessed monoclinic lattice when the annealing temperature was below 650 degrees C, while the higher temperature distorted lattice structure resulting in the formation of Ta3N5 and poor photocatalytic performance. The photocatalytic activity of the N-NaTaO3 confirmed that a proper N content was crucial to expand the adsorption region of light, as well as to enhance photocatalytic efficiency. Moreover, the N-NaTaO3 products with doped-N/Ta ratio of about 0.06 exhibited the highest photocatalytic activity, having 10 times higher degradation rate constant than those of the as-prepared NaTaO3, and possessed outstanding cycle stability.