Preparation and photoluminescence of single-crystalline GdVO4:EU3+ nanorods by hydrothermal conversion of Gd(OH)3 nanorods

This paper reports a hydrothermal conversion process of a rare earth nanostructure, Gd(OH)(3) nanorods, into photoluminescent GdVO4 nanorods, together with the investigation on the morphological changes and related photoluminescent properties. Gd(OH)(3) precursor with nanorod shape, uniform diameter, and good crystallinity was prepared by a colloidal hydrothermal method. High-resolution transmission electron microscopy (HRTEM) revealed the single-crystal nature of the precursor and preferred growth along the [001] direction. After hydrothermal conversion, well-crystallized GdVO4 nanorods were obtained. The growth direction of the newly formed nanorods was also confirmed as [001] from HRTEM investigation. TEM observations of the nanorod samples hydrothermally treated for 4 and 8 h indicated that the nanorods were formed by a surface deposition with a subsequent crystal growth procedure, during which the VO43- deposited onto the surface of the Gd(OH)(3) precursor and then reacted gradually with the inner core to generate the GdVO4 nanorods. Such GdVO4 nanorods showed strong red emission upon UV illumination when 5 at % Eu3+ was doped into the lattice, due to the intrinsic Eu3+ transition between D-5(0) and F-7(j) configuration, showing potential application of the nanorods in the photoluminescence field.