Tracking Initial Fe(II)-Driven Ferrihydrite Transformations: A Mossbauer Spectroscopy and Isotope Investigation.

ABSTRACT: Transformation of nanocrystalline ferrihydrite to more stable microcrystalline Fe(III) oxides is rapidly accelerated under reducing conditions with aqueous Fe(II) present. While the major steps of Fe(II)-catalyzed ferrihydrite transformation are known, processes in the initial phase that lead to nucleation and the growth of product minerals remain unclear. To track ferrihydrite-Fe(II) interactions during this initial phase, we used Fe isotopes, Mössbauer spectroscopy, and extractions to monitor the structural, magnetic, and isotope composition changes of ferrihydrite within ∼30 min of Fe(II) exposure. We observed rapid isotope mixing between aqueous Fe(II) and ferrihydrite during this initial lag phase. Our findings from Mössbauer spectroscopy indicate that a more magnetically ordered Fe(I

SUBMITTER: Latta D 

PROVIDER: S-EPMC10591510 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature