Highly Uniform Gd(OH)3 and Gd2O3:Eu3+ Nanotubes: Facile Synthesis and Luminescence Properties

Uniform Gd(OH)(3) nanotubes have been prepared via a simple wet-chemical route at ambient pressure and low temperature, without any catalysts, templates, or substrates, in which Gd(NO3)(3) was used as the gallium source and ammonia as the alkali. SEM and TEM images indicate that the as-obtained Gd(OH)3 entirely consists of uniform nanotubes in high yield with diameters of about 40 nm and lengths of 200-300 nm. The temperature-dependent morphological evolution and the formation mechanism of the Gd(OH)(3) nanotubes were investigated in detail. Furthermore, the Gd2O3 and Eu3+-doped Gd2O3 nanotubes, which inherit their parents' morphology, were obtained during a direct annealing process in air. The corresponding Gd2O3:Eu3+ nanotubes exhibit the strong red emission corresponding to the D-5(0)-F-7(2), transition of the Eu3+ ions under UV light or low-voltage electron beam excitation, which might find potential applications in the fields such as light-emitting phosphors, advanced flat panel displays, or biological labeling.