Margate Julien, Virot Matthieu, Dumas Thomas, Bayle Simon, Menut Denis, Bonato Laura, Broussard Emilie, Molière Fanny, Hours Charles, Venault Laurent, Nikitenko Sergey I
ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France.
ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France.
Ultrason Sonochem. 2025 Jun;117:107346. doi: 10.1016/j.ultsonch.2025.107346. Epub 2025 Apr 8.
While bulk PuO is known to be strongly resistant to dissolution, even under ultrasonic irradiation, this study demonstrates that nanometric PuO samples can exhibit enhanced reactivity when sonicated under an Ar/(20 %)O atmosphere. Sonication of powdered PuO nanoparticles (∼5 nm) in pure water was found to be ineffective. In contrast, colloidal PuO nanoparticles (∼3 nm) prepared via hydrolysis exhibited markedly different behavior, leading to the accumulation of Pu(VI), with sonochemically-generated HO playing a crucial role in the process. Further investigations identified an intermediate species implicated in the dissolution process, agreeing with a recently described Pu(IV) peroxide compound. Despite the chemical similarity of the PuO nanoparticles, this study highlights their dual reactivity under conditions favoring HO formation highlighting an important role of the material's preparation method. Beyond underscoring the critical role of HO in the reactivity of PuO nanoparticles, this study also evidences a potential pathway for their transformation under environmental conditions where radiolysis can generate similar chemical environments.
虽然已知块状二氧化钚即使在超声辐照下也具有很强的抗溶解性，但本研究表明，纳米级二氧化钚样品在氩气/（20%）氧气气氛中超声处理时可表现出增强的反应活性。在纯水中对粉末状二氧化钚纳米颗粒（约5纳米）进行超声处理被发现是无效的。相比之下，通过水解制备的胶体二氧化钚纳米颗粒（约3纳米）表现出明显不同的行为，导致钚（VI）的积累，声化学产生的羟基自由基在该过程中起关键作用。进一步的研究确定了一种参与溶解过程的中间物种，这与最近描述的一种过氧化钚（IV）化合物一致。尽管二氧化钚纳米颗粒在化学性质上相似，但本研究突出了它们在有利于羟基自由基形成的条件下的双重反应活性，强调了材料制备方法的重要作用。除了强调羟基自由基在二氧化钚纳米颗粒反应活性中的关键作用外，本研究还证明了在辐射分解可产生类似化学环境的环境条件下它们转化的潜在途径。
