Highly redox active cerium oxide (CeO2) nanoparticles used in diesel engine catalytic converters can cause oxidative damage to organisms if released in drinking water. Therefore, it is important to better understand their stability and transport in aqueous environments where redox-active species such as ferrous ions are present. In this work, we have demonstrated that the presence of Fe2+ in CeO2 colloidal suspensions resulted in greater dispersion of CeO2 nanoparticles. Furthermore, redox reactions by Fe2+ at the Ce(IV)O2 nanoparticle surface released more than 250 times more aqueous Ce3+ (which is more toxic than Ce4+) in solution compared to systems without Fe2+, while creating an iron(III) (hydr)oxide CeO2 surface coating. The coupled effect of promoted dissolution of toxic Ce3+ ions and the formation of Fe3+, an effective sorbent for aqueous heavy metal contaminants, on the CeO2 nanoparticle surface have significant implications for downstream drinking water contaminant fate and transport.

Promoted dispersion of cerium oxide nanoparticles from Fe2+-induced redox reactions at the nanoparticle surface

249th National Meeting (2015)

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