Nanoparticle Fe as a reactive constituent in air, water and soil

The goal of the proposed work is to understand the reactivity of iron (Fe) oxide nanoparticles in air, water, and soil environments. Fe oxide particles in the nanometer size range (< 100 nm) are ubiquitous in nature and their occurrence ranges from ultra-fine mineral dust in the atmosphere to nanocrystalline precipitates in the hydrosphere. The remarkable reactivity of Fe oxides has led to intense interest in the origin and reactivity of nanoparticle Fe oxides in natural environments. Research into the reactivity of nanoparticle Fe oxides has been primarily aimed at understanding the bonding characteristics of atoms adsorbed at the surface. It is now recognized, however, that the behavior of Fe in the environment is strongly influenced by bacterially driven redox reactions, as well as the local chemistry and nature of mineral surfaces in rocks and soils, and by the presence of water. Therefore, detailed investigations of the redox chemistry of Fe oxide nanoparticles under conditions analogous to nature are needed to evaluate the role of these tiny particles in the cycling of Fe in the environment. It is also hypothesize that unique reaction mechanisms occur at the surface of Fe oxide nanoparticles that do not extrapolate outside of the nanoscale domain. This is a new project that is being done in collaboration with Professor Michelle Scherer (Environmental Engineering) which is being funded by the National Science foundation through the NIRT program (Nanoscience Integrative Research Team). Other investigators contributing to the U of Iowa NIRT include those from UC Berkeley, University of Wisconsin and Coe College.