SYNTHESIS OF URANIUM OXIDE NANOPARTICLES IN AQUEOUS SOLUTIONS

摘要

Uranium oxide nanoparticles can be used as a catalyst for a number of chemical reactions, including gas-phase destruction of organic chemicals. These particles can also be used in high-temperature catalytic applications such as the decomposition of water. In this paper we present a method for preparation of uranium oxide nanoparticles at room temperature using a surfactant templating-crystal growth technique. The size and shape of the particles were controlled by selecting appropriate surfactant micelles. Hexagonal-shaped particles were obtained when PEG-400 was used as the surfactant, whereas particles were rodlike shaped when Pluronic-123 was employed. Particles were characterized using transmission electron microscopy, Fourier transform infrared spec- troscopy (FTIR), and ultraviolet-spectrometric analysis. They were found to be 500 to 1000 nm in length for hexagonal particles and 100 to 500 nm in length and 20 to 40 nm in width for rodlike particles. The FTIR spectra taken in diffuse reflectance infrared Fourier transform mode showed an infrared band at 910 cm~(-1) corresponding to asymmetric U=0 stretching vibration of uranyl species. When the sample was heated at 600℃, four bands-at 353, 412 to 475, 745, and 805 cm~(-1)-were observed in the Raman spectrum. The bands in the range of 412 to 475 cm~(-1) and at 745 cm~(-1) could be attributed to U_3O_8 and UO_2~(+2) (uranyl) species that are present in the sample.