Synthesis and catalytic properties of uranium oxide nanoparticles on porous surface of oxidized aluminum

The principal objective of this work is to study the processes of forming the variable-valence uranium oxides on the surface of oxidized aluminum. To this end, the photochemical formation processes of uranium complexes with variable valence have been investigated upon irradiation of UO2 (ClO4)×5H2O solutions in acetone by light-emitting diodes (410-450 nm), deposition on the porous surface of oxidized aluminum with subsequent transformation into the highly reactive uranium oxides. With the use of a high-power light emitting diode (maximal λ=420-430 nm) irradiating the systems uranyl perchlorate-acetone, it has been found that in such systems the photocondensation of acetone takes place. In the condensation products the nanoclusters of penta- and tetravalent uranium are formed due to the photochemical processes. When the products of acetone and uranium photocondensation are deposited with the use of hydrogen peroxide on a porous surface of oxidized aluminum, the nanoclusters of sexavalent uranium are formed, strongly bonded to the substrate. To produce highly reactive uranium oxides on the surface of pores, oxidized aluminum plates containing uranium peroxide have been thermally treated at different temperatures. By heating the aluminum substrate and annealing the deposited uranium peroxide at 400-450 C one can produce uranium trioxides of the type β-UO3 and by thermal treatment at 500-600 °C - various forms of U3O8. (authors)