Formation of hydroxysulphate and hydroxycarbonate green rusts in the presence of zinc using time-resolved in situ small and wide angle X-ray scattering

摘要

The formation and transformation of hydroxysulphate (GRSO_4) and hydroxycarbonate (GRCO_3) Green Rusts were studied in situ using synchrotron-based time-resolved small and wide angle X-ray scattering. The time-resolved data revealed, for the first time, the pH dependent transition from poorly-ordered schwertmannite (pH <6.5) into GRSO_4 (pH approx 6.8) followed by GRCO_3 (at pH approx 9.6). These data also showed that the addition of Zn to the starting sulphate Fe~(2+)/Fe~(3+) solution resulted in a change in size of the GR unit-cell due to substitution of Zn into the GR structure.