Synthesis and photocatalytic activity of N-doped NaTaO3 compounds calcined at low temperature

N-doped NaTaO3 compounds (NaTaO3−xNx) were successfully synthesized using NaTaO3 prepared at low calcination temperature as starting material and melamine (C3H6N6) as nitrogen source. The as-prepared NaTaO3−xNx samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectra. The XRD results indicate that the crystallization temperature of NaTaO3 is up to 700 °C and the doping of N does not lead to significant structural changes. Moreover, as observed by SEM images, the particle sizes of resultant NaTaO3−xNx are in the range of 100-150 nm, which are much smaller than NaTaO3 particles synthesized by traditional solid state reaction method. The photocatalytic activities of NaTaO3−xNx were examined by methylene blue (MB) aqueous solution under UV light. It is found that the photocatalytic activity of NaTaO3−xNx depend strongly on the doping content of N, and sample NaTaO2.961N0.039 shows the highest photocatalytic activity for the degradation of MB. Furthermore, it is also found that NaTaO3−xNx catalysts display super structural stabilities during photocatalytic degradation, and could recover their photocatalytic activity after calcination at 500 °C, suggesting a promising utilization of such photocatalyst.