Synthesis of a Se0/Calcite Composite Using Hydrothermal Carbonation of Ca(OH)2 Coupled to a Complex Selenocystine Fragmentation

G. Montes-Hernandez (1) , L. Charlet (1) , F. Renard (2, 3) , A. C. Scheinost (4, 5) , Maïté Bueno (6) , A. Fernandez Martinez (1, 7)

1 LGIT - Laboratoire de Géophysique Interne et Tectonophysique
2 PGP - Physics of Geological Processes [Oslo]
3 LGCA - Laboratoire de Géodynamique des Chaines Alpines
4 Institute of Resource Ecology [Dresden]
5 ESRF - European Synchrotron Radiation Facility
6 IPREM - Institut pluridisciplinaire de recherche sur l'environnement et les matériaux
7 ILL - Institut Laue-Langevin

Elemental selenium (Se0)/calcite composites were synthesized in a batch system by hydrothermal carbonation of calcium hydroxide under high CO2−Ar pressure (90 bar) and high temperature (90 °C) coupled to a complex selenocystine fragmentation. Under O2-poor conditions, the composite consisted predominantly of spherical, amorphous nanoparticles of elemental red selenium (<500 nm) deposited on the calcite matrix. Conversely, under O2-rich conditions, the composite consisted rod-shaped, well-crystallized microparticles of elemental gray selenium (<25 µm) dispersed in the calcite matrix. The carbonate matrix was constituted by nano- to microrhombohedral crystals (<2 µm) and micrometric agglomerates and/or aggregates (<5 µm). Our results present a new synthesis path to Se0/calcite composites, with spherical or rod-shaped Se0 morphology with high potential for medical (e.g., dietary supplement) or industrial (e.g., pigments) applications. Furthermore, this study may have implications in the field of biomineralization.

Domains: Earth Sciences

G. Montes-Hernandez, L. Charlet, F. Renard, A. C. Scheinost, Maïté Bueno, et al.. Synthesis of a Se0/Calcite Composite Using Hydrothermal Carbonation of Ca(OH)2 Coupled to a Complex Selenocystine Fragmentation. Crystal Growth & Design, 2008, 8 (7), pp.2497 à 2504. ⟨10.1021/cg800141p⟩. ⟨insu-00351971⟩