Controlled Synthesis of Thorium and Uranium Oxide Nanocrystals

Abstract

Very little is known about the size and shape effects on the properties of actinide compounds. As a consequence, the controlled synthesis of well-defined actinide-based nanocrystals constitutes a fundamental step before studying their corresponding properties. In this paper, we report on the non-aqueous surfactant-assisted synthesis of thorium and uranium oxide nanocrystals. The final characteristics of thorium and uranium oxide nanocrystals can be easily tuned by controlling a few experimental parameters such as the nature of the actinide precursor and the composition of the organic system (e.g., the chemical nature of the surfactants and their relative concentrations). Additionally, the influence of these parameters on the outcome of the synthesis is highly dependent on the nature of the actinide element (thorium versus uranium). By using optimised experimental conditions, monodisperse isotropic uranium oxide nanocrystals with different sizes (4.5 and 10.7 nm) as well as branched nanocrystals (overall size ca. 5 nm), nanodots (ca. 4 nm) and nanorods (with ultra-small diameters of 1 nm) of thorium oxide were synthesised.

Synthesis of ThO2nanostructures through a hydrothermal approach: influence of hexamethylenetetramine (HMTA) and sodium dodecyl sulfate (SDS)

“…Fig. 7 shows the SEM images of the samples prepared at different temperatures under otherwise 50 identical conditions (Table 1, sample [17][18][19]. No product was obtained at 80 °C, suggesting the incomplete decomposition of HMTA.…”

“…Among them, thorium dioxide, a very important inorganic material in nuclear industry and catalysis, has been prepared using various methods [11][12][13][14][15][16] . For example, different morphologies of small ThO 2 25 nanocrystals, such as branched nanocrystals, nanodots and nanorods, have been synthesized through an organic-phase thermolysis method using thorium acetate and thorium acetylacetonate as the metal source in a mixture solution of oleic acid, oleylamine and octadecene 17,18 . This method has been 30 extended to the synthesis of other actinide oxide nanocrystals, such as UO 2 , NpO 2 , PuO 2 and the mixing oxide of thorium/uranium nanocrystals [19][20][21] .…”

Uranium Oxide Nanocrystals by Microwave‐Assisted Thermal Decomposition: Electronic and Structural Properties

“…5 nm) that were surface passivated by oleylamine through chelating bidentate interactions as suggested by IR spectroscopy. [7,8] Wang et al prepared spherical UO 2 nanoparticles with an average diameter of 100 nm via hydrothermal reduction of uranyl acetate using ethylenediamine. The reaction was performed in an autoclave heated at 160°C for 48 h. [9] A room temperature and surfactant-free synthesis of UO 2 nanoparticles was presented by Nenoff et al in 2011.…”

Synthesis of ordered mesoporous U3O8 by a nanocasting route

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Ordered mesoporous U 3 O 8 has been synthesized by a nanocasting route using mesoporous silica (KIT-6 and SBA-15) as templates and characterized by using XRD, SEM and nitrogen adsorption/desorption techniques.Recently, there has been great interest in synthesis of various kinds of uranium based-nanomaterials, since these materials can be applied in catalysis area and may become new building blocks for the preparation of innovative nuclear fuels [1][2][3][4][5][6]. Among them, porous uranium oxides are expected to have better performance because of its large surface area and the ability to retain the fission gas into its pores as nuclear fuel [5,7,8].

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