Synthesis and multi-scale properties of PuO₂ nanoparticles: recent advances and open questions

Abstract

The review focuses on the recent relevant progresses observed about PuO2 nanoparticle syntheses and characterizations including the recently deciphered electronic, structural and physico-chemical properties.

Synthesis of Nanocrystalline PuO2 by Hydrothermal and Thermal Decomposition of Pu(IV) Oxalate: A Comparative Study

“…It can be observed that the lattice parameter is essentially constant and independent of the method applied and of the reaction conditions ( Figure 5 ). Moreover, this is very close to the lattice parameter of bulk PuO 2 [ 31 , 32 , 33 ]. By contrast, the crystallite size is strongly affected by the method (and, hence, the temperature).…”

First observation of [Pu6(OH)4O4]12+ cluster during the hydrolytic formation of PuO2 nanoparticles using H/D kinetic isotope effect

“…2 nm PuO 2 -like NPs, much less is known about their formation mechanism. 11–14 The description of Pu oxo–hydroxo clusters, with a characteristic size situated somewhere between the ones of ionic and colloidal species of Pu, highlighted the relation between their core structures revealing some striking similarities with bulk PuO 2 . This suggested that bigger clusters could be formed from the assembly of those smaller molecular fragments.…”

Investigation of the Plutonium(IV) Interactions with Two Variants of the EF-Hand Ca-Binding Site I of Calmodulin

“…Actually, in the visible spectra recorded with CaMWT at pH 6, the intense band at 456 nm followed by a shoulder at 475 nm and the double band at 659 and 686 nm were similar to the features identified for these hexanuclear Pu(IV) clusters. ,, DOTA, acetate, and glycine clusters present similar shells around Pu, two oxygen shells at 2.19 to 2.29 Å (two or four oxygen atoms, respectively) and at 2.36 to 2.42 Å (four, six, or seven oxygen atoms, respectively). The two shells of Pu(IV) are identical with four Pu(IV) in the axial plane at 3.76 to 3.77 Å and one Pu(IV) in the equatorial plane at 5.31 to 5.35 Å. − The clusters decorated by acetate or glycine showed the presence of a water molecule in the Pu(IV) coordination sphere. , This water increased the number of oxygen atoms in the Pu–O shell but did do not change the main characteristics of the complex, notably the Pu(IV)–Pu(IV) distance, which is always shorter than in colloidal structures. ,− …”

“…40 Another species, PuO 2 , can take a great diversity of forms. 34,41 Multiple structures have been determined with Pu−O bond distances from 2.20 to 2.44 Å and Pu−Pu distances between 3.79 and 3.90 Å. In particular, the PuO 2 solid reference from oxalate conversion has a Pu−Pu distance at 3.81 Å.…”