RT Journal Article
T1 Microscopic and spectroscopic investigation of thecalcite surface interacted with Hg(II) in aqueous solutions
A1 Godelitsas, Athanasios
A1 Astilleros García-Monge, José Manuel
A1 Hallam, K.R.
A1 Löns, J.
A1 Putnis, Andrew
AB The interaction of the {101¯4} cleavage surface of calcite with Hg(CH3COO)2 aqueous solutions withconcentration of 5 mM Hg(II) (pH ≈3.5), was investigated using microscopic and spectroscopictechniques. In situ atomic force microscopy experiments showed that surface microtopography changessignificantly as a result of the interaction, and that the initial rhombic etch pits induced by H2Odissolution are rapidly transformed to deeper etch pits exhibiting an unusual triangular shape. Thegrowth of these etch pits is strongly anisotropic, moving faster along the [22¯1] direction than along the[010] direction (with step-retreat velocities of ~12 nm s –1 and ~4 nm s–1, respectively). The modifiedetch pits are due to Hg(II) sorption in the surface, rather than due to the effect of the acetate anion. Thesorption (adsorption and probably absorption also) of Hg(II), in the first minutes of the interaction, isshown by X-ray photoelectron spectroscopy. After ~2 h, the triangular etch pits are interconnected toform larger hexagonal etch pits, while Hg(II)-bearing phases (confirmed later by SEM-EDS) grow ontothe surface through a heterogeneous nucleation process. The crystal growth of orthorhombic(montroydite-type) hydrated Hg(II) oxide (HgO·nH2O) on the surface of calcite was confirmed byXRD patterns and FT-IR spectra from samples exposed for longer times to Hg(CH3COO)2 solution.
PB Mineralogical Society (Great Britain)
SN 0026-461X
YR 2003
FD 2003
LK https://hdl.handle.net/20.500.14352/57901
UL https://hdl.handle.net/20.500.14352/57901
LA eng
DS Docta Complutense
RD 9 abr 2025