Zhang, Yiwei; Chao, Cong; Pineda, Miguel; Fraga, Eric S; Idota, Naokazu; Tsukahara, Takehiko; Angeli, Panagiota; (2025) Redox-driven agglomeration and dissolution of cerium oxide nanoparticles in hydrogen peroxide solutions. Chemical Engineering Journal , 521 , Article 166881. 10.1016/j.cej.2025.166881.

Text Chao_CEJ.pdf - Accepted Version Access restricted to UCL open access staff until 14 August 2026. Download (621kB)

Abstract

Large amounts of nuclear fuel debris generated during the Fukushima Daiichi Nuclear accident present unpredicted but severe environmental and ecological challenges. A comprehensive understanding of the denaturation behaviour of nanoscale nuclear fuel particles, particularly plutonium oxide (PuO2), during retrieval and cutting processes is crucial for ensuring safe handling and long-term environmental remediation. Cerium oxide (CeO2) is widely used as a non-radioactive surrogate for PuO2 due to their comparable crystal structures and physicochemical properties. In this study, the agglomeration and dissolution behaviour of CeO2 nanoparticles (NPs) in hydrogen peroxide (H2O2) solutions were investigated to gain mechanistic insights into the potential denaturation processes of PuO2 NPs. Our results reveal that CeO2 NPs exhibit significant agglomeration and slow dissolution across a broad range of H2O2 concentrations (1.2 × 10−5 M to 1.2 M), with agglomeration increasing as H2O2 concentration decreases. The surface redox reaction between CeO2 NPs and H2O2 was identified as the main contributor to both agglomeration and subsequent dissolution of CeO2 NPs, which is strongly influenced by H2O2 concentration, particle size, and the presence of other metal oxides. Reactive oxygen species, including superoxide (O2−) and peroxide (O22−), are generated within the reaction and rapidly absorbed onto the CeO2 nanoparticle surfaces, reversing their surface charge and leading to rapid initial agglomeration of CeO2 NPs. This early-stage agglomeration behaviour was successfully modelled using a diffusion-limited agglomeration (DLA) kinetic model fitted with the Levenberg-Marquardt algorithm. These findings provide valuable insights into the agglomeration and dissolution behaviour of CeO2 NPs in a wide range of H2O2 and have significant implications for the development of effective reductive remediation strategies for plutonium-containing nuclear debris as well as related wastewater treatment processes.

Download activity - last month

Export as JSONCSVXML

Download activity - last 12 months

Export as JSONCSVXML

Downloads by country - last 12 months

Export as JSONXMLCSV

Archive Staff Only

View Item