Optimization hydrothermal synthesis conditions for nano-sized (Na0.5Bi0.495Nd0.005)TiO3 particles by an orthogonal experiment and their luminescence performance

By designing an orthogonal experiment with four factors and three levels, (Na 0.5 Bi 0.495 Nd 0.005 )TiO 3 (NBT-Nd) nanopowders were prepared using a hydrothermal method under different conditions to determine the optimum hydrothermal synthesis conditions. The synthesized NBT-Nd nanopowders were characterized using X-ray diffraction measurement, ultraviolet–visible spectra, photoluminescence spectra, and transmission electron microscopy to evaluate the orthogonal experimental conditions. The results showed that NBT-Nd powders with excellent crystalline and luminescence properties could be obtained at 160°C, with a 16 h reaction time, 8 mol·L −1 NaOH, and with 0.4489 g C 19 H 42 BrN. The optimized hydrothermal method-prepared NBT-Nd powder has a rather pure rhombohedral perovskite structure at room temperature, and exhibits an aggregated polycrystalline structure containing nanotubes and nano-sized particles. Under excitation of 247 nm light, strong fluorescence emissions are excited at 423 nm and 441 nm in the NBT-Nd powder that were generated by transitions of Nd 3+ from 2 D 5/2 to 4 I 9/2 and from 4 G 11/2 to 4 I 9/2 , respectively. Through CIE1931 chromaticity calculation of the emission peaks, the NBT-Nd powder was shown to emit indigo blue fluorescent light.