Naslov
Formation of AgFeO2, alpha-FeOOH, and Ag2O from mixed Fe(NO3)(3)-AgNO3 solutions at high pH

Autori
Krehula, Stjepko ; Musić, Svetozar

Izvornik
Journal of molecular structure (0022-2860) 1044 (2013); 221-230

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Silver ferrite ; Goethite ; Silver oxide ; XRD ; 57Fe Mössbauer ; FE-SEM

Sažetak
Precipitation of ternary oxide silver ferrite (AgFeO2), iron oxyhydroxide goethite (α-FeOOH) and silver(I) oxide (Ag2O) from mixed Fe(NO3)3–AgNO3 solutions in a whole [Ag+]:[Fe3+] concentration ratio range at high pH was investigated using X- ray powder diffraction (XRD), 57Fe Mössbauer, FT- IR and UV–Vis–NIR spectroscopies and field emission scanning electron microscopy (FE-SEM). Strong alkalis organic tetramethylammonium hydroxide (TMAH) or inorganic NaOH were used as precipitating agents. Monodispersed lath-like α- FeOOH particles were formed from a pure Fe(NO3)3 solution. The presence of Ag+ ions influenced the formation of the delafossite-type ternary oxide AgFeO2 beside α-FeOOH. The positions of XRD and Mössbauer lines did not suggest any significant incorporation of Ag+ ions into the α-FeOOH structure. AgFeO2 was formed in the precipitation system with the equimolar initial [Ag+]:[Fe3+] concentration ratio. The size and shape of AgFeO2 particles, as well as their structural polytype (2H or 3R), were dependent on reaction temperature, aging time and alkali used. In systems with an excess of Ag+ ions mixtures of AgFeO2 and Ag2O were formed. Single phase Ag2O precipitated from a pure AgNO3 solution.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

Napomena
Rad je prezentiran na skupu XXXIst European Congress on Molecular Spectroscopy "Molecular spectroscopy and molecular structure 2012", održanom od 26.–31.08.2012.g., Cluj-Napoca, Rumunjska.

POVEZANOST RADA