Synthesis of Fe(II-III) hydroxysulphate green rust by coprecipitation

• Published in: Solid state sciences 2002, Vol.4 (1), p.61-66
• Main Authors: Géhin, Antoine, Ruby, Christian, Abdelmoula, Mustapha, Benali, Omar, Ghanbaja, Jaafar, Refait, Philippe, Génin, Jean-Marie R.
• Format: Article
• Language: English
• Subjects: AFM; Chemical Physics; Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Coprecipitation; Exact sciences and technology; Green rust; Inorganic chemistry and origins of life; Inorganic compounds; Iron(II-III) hydroxysulphate; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Mossbauer effect; other γ-ray spectroscopy; Mössbauer effect; other γ-ray spectroscopy; Mössbauer spectroscopy; Physics; Preparations and properties; Salts; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; TEM; XRD
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/S1293-2558(01)01219-5

Iron(II-III) hydroxysulphate precipitates were prepared in absence of other compounds by coprecipitation that consists of mixing solutions of iron(II) and iron(III) salts with NaOH solution in adequate proportions. Precipitates were characterised by transmission Mössbauer spectroscopy (TMS), XRD, TEM and AFM. Mössbauer spectrum measured at 15 K was composed of Fe(II) and Fe(III) doublets with δ=1.33 and 0.51 mm s −1, and Δ=2.88 and 0.43 mm s −1, respectively. The Fe(II)/Fe(III) ratio of 2 is independent of the solution ratio set at 3 that confirms the composition, [Fe II 4Fe III 2(OH) 12] 2+·[SO 2− 4 · m H 2O] 2−. XRD analysis led to hexagonal unit cell parameters of a H= b H=0.318±0.004 nm and c H=1.090±0.004 nm. The value a H=0.314±0.002 nm was obtained by TEM diffraction pattern corresponding to ( h k 0 ) planes and displayed a distribution of hexagonal plates (10