Characterization of the effects of silicon on the formation of goethite

Abstract Goethite samples were synthesised with different sodium silicate concentrations (0, 10−5, 10−4, 10−3 and 10−2 M) in the initial aqueous solution. X-ray diffraction (XRD), Mossbauer spectrometry, inductively coupled plasma mass spectrometry (ICP-MS) and transmission electron microscopy (TEM) were used to investigate the influence of Si content on the formation and physical characteristics of goethite. Mossbauer spectroscopy and TEM results demonstrate that the particle size changes as the sodium silicate content increases. XRD results (lattice parameters, line width and mean coherence length values) do not show any indication that Si species would substitute for Fe in the goethite structure.