Nanosize effects on the kinetics of contaminant reduction by iron and iron oxides

The effects of nanosize on the kinetics of contaminant reduction by iron and iron oxides were studied. A graphical tool for assessing relative rates of reactions occurring on particle surfaces was used. A log-log plot of surface area normalized rate constants (k_SA) vs. mass normalized rate constants (k_M) was presented. Nanoparticles with an Fe⁰ core and Fe₃O₄ shell was more reactive with CCl₄ than Fe₃O₄ or Fe₂O₃/Fe^II under all circumstances, suggesting that Fe⁰ increased the reactivity of the particle even though it might not be in contact with the solution. Comparisons such as the latter, however, effectively assumed that the specific surface area of the particles was an adequate (ideally accurate, but minimally unbiased) measure of reactive surface area. This was not the case for Fe⁰ that contained large amounts of oxide or Fe^II oxides. This is an abstract of a paper presented in the 230th ACS National Meeting (Washington, DC 8/28/2005-9/1/2005).