Structural and spectroscopic characteristics of terbium hydroxide/oxide nanorods and plates

Tb(III) complexes with morphologies of nanorods and plates were prepared by a hydrothermal method. Post-thermal treatment was then applied to obtain Tb(IV) oxides with the same morphologies. Their nanostructures were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) crystallography, UV-vis absorption, FT-IR, Raman, X-ray photoelectron spectroscopy (XPS), and photoluminescence imaging spectroscopy. Strong photoluminescence signals between 470 and 720 nm were attributed to the 5D4→7FJ (J =6, 5, 4, 3) transitions of Tb(III). The Tb(III) complex and Tb(OH)3 were found to be converted to Tb(IV) oxide upon thermal annealing at 700 °C. The oxidation state of Tb(III) was changed to non-luminescent Tb(IV), as clearly evidenced by UV-vis absorption, change in sample color, XPS, photoluminescence and XRD patterns.