Yttrium Oxide Nanowires

In summary, we have prepared three wirelike yttrium compounds by hydrothermal method, which were hexagonal yttrium hydroxide, yttrium oxide nitrate hydroxide, and yttrium chloride hydroxide. Hexagonal yttrium hydroxide nanowires were synthesized as single crystals from yttrium oxide powder by a simple acetic acid-assisted hydrothermal method under near neutral conditions. The nanowires show unusual, bundle-like morphology with diameter of 20-50 nm and aspect ratio of 600-2000. The growth of nanowires involved the oriented attachment of 1D nanocrystals to form microrods and selective dissolution from defect sites to form bundles of nanowires. Another wirelike yttrium compound, Y4O(OH)9(NO3) were obtained through conventional precipitationhydrothermal synthetic route under basic condition. These nanowires were straight and well-dispersed single crystals, with extraordinary high aspect ratio and uniform diameter ranging from 30 to 50 nm. By substituting yttrium nitrate with yttrium chloride, yttrium chloride hydroxide nanowires with diameter of 100-300 nm and length up to tens of microns were synthesized at pH 9.50-10.25 via hydrothermal reaction. All of the three compounds could be utilized to fabricate yttrium oxide nanowires through thermal treatment. This one dimensional (1D) structure may lead to new opportunities in yttrium chemistry. For example, the yttrium oxide nanowires showed intriguing hightemperature stability. Our experiments suggested that after calcination at 1400 °C, the yttrium oxide nanowires obtained from yttrium chloride hydroxide remained their wire shape, which makes it promising material for refractory applications, such as refractory insulation and high temperature gas filtration. Furthermore, the formation of the three compounds all went through a dissolution-crystallization procedure. Therefore, homogeneous rare earth doped yttrium oxide nanowires could be prepared by using mixture of yttrium and other rare earth oxide as starting material. By this means, 1D luminescent materials like Y2O3:Eu3+ nanowires can be fabricated, which may extend its application and benefit the understanding of the luminescent mechanism in low dimensional materials.