Hydrothermal synthesis, characterization, and luminescence of BaWO4 nanorods

Barium tungstate (BaWO4) nanorods were synthesized by a hydrothermal process with the assistant of cetyltrimethyl ammonium bromide (CTAB). The samples were analyzed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and photoluminescence measurements. The XRD and FT-IR results show that BaWO4 samples can be indexed as a pure tetragonal scheelite structure. The SEM results show that the morphologies are nanorods with a diameter about 45 nm and a length exceeding 1 mu m. The CTAB and "oriented attachment" play key roles in the growth of BaWO4 nanorods in the hydrothermal process. When excited at 265 nm, BaWO4 nanorods show the intrinsic emission band centered at 467 nm. The calculated luminescence lifetime of WO4 (2-) in BaWO4 is 8.9 mu s.