Preparation: |
procedure of [SC91] which involved the hydrolysis of a Fe(NO3)3·9H2O solution by KOH with subsequent heating at 70 °C for 60 h; goethite concentrated by centrifugation and then extracted with acidified hydroxyl-amine hydrochloride
(0.25 mol/L NH2OH·HCl and 0.25 mol/L HCl; Chao and Zhou, 1983) three times to remove poorly crystalline iron oxides; washed repeatedly in 0.003 mol/L Ca(ClO4)2, dialyzed against deionized water, freeze-dried |