Silicate coprecipitation reduces green rust crystal size and limits dissolution-precipitation during air oxidation.

ABSTRACT: Green rusts (GR) are mixed-valence iron (Fe) hydroxides which form in reducing redox environments like riparian and wetland soils and shallow groundwater. In these environments, silicon (Si) can influence Fe oxides' chemical and physical properties but its role in GR formation and subsequent oxidative transformation have not been studied starting at initial nucleation. Green rust sulfate [GR(SO₄)] and green rust carbonate [GR(CO₃)] were both coprecipitated from salts by base titration in increasing % mol Si (0, 1, 10, and 50). The minerals were characterized before and after rapid (24 h) aqueous air-oxidation by x-ray diffraction (XRD), scanning electron microscopy (SEM), Fe extended x-ray absorption fine structure spectroscopy (EXAFS), and N₂-BET surface a

SUBMITTER: Betts AR 

PROVIDER: S-EPMC11520823 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature