Characterization of NaTaO₃ synthesized by ultrasonic method

NaTaO₃ perovskite-like materials were synthesized using sodium acetate and tantalum ethoxide as precursors in an ultrasonic bath at room temperature. The pristine sample was thermally treated at 600 °C and characterized using XRD, N₂ physisorption, DRS, SEM and TEM techniques. The structural characterization by X-ray powder diffraction revealed that the crystallization of the NaTaO₃ phase prepared at 600 °C showed agglomerates sizes in the micrometric scale, as confirmed by scanning electron microscopy (SEM). On the other hand, well-defined NaTaO₃ particles in the nanometric scale were determined using TEM. It was found that, for the treated sample, the band gap and BET area was 3.8 eV and 9.5 m ² g^-1, respectively. The annealed perovskite, deposited onto ITO glass, presented an important variation in the open circuit potential transient during UV light irradiation in neutral solution, compared with its counterpart prepared by solid-state method. These intrinsic properties, given by the preparation route, might be appropriate for increase its photocatalytic activity.