| Autor: |
Jonathan B Junio, Marlon T Conato, Candy C Mercado |
| Jazyk: |
angličtina |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Materials Research Express, Vol 8, Iss 9, p 095501 (2021) |
| Druh dokumentu: |
article |
| ISSN: |
2053-1591 |
| DOI: |
10.1088/2053-1591/ac2192 |
| Popis: |
Tin (Sn ^2+ ) and strontium (Sr ^2+ ) are potential replacements to lead (Pb ^2+ ) in perovskite synthesis since Sn is on the same IVA group in the periodic table as Pb while Sr is a promising alternative according to Goldschmidt’s rules and quantum mechanical analysis. The crystal radii of their ions are also nearly identical with Pb ^2+ = 1.33 Å, Sn ^2+ = 1.36 Å, and Sr ^2+ = 1.32 Å. In this study, both Sn and Sr were explored in transforming calcite, a polymorph of calcium carbonate (CaCO _3 ) into a leaving group in the first step of a sequential ion-exchange reaction towards perovskite formation. Instead of forming the intermediate tin carbonate (SnCO _3 ), the reaction resulted in the formation of gypsum or calcium sulfate dihydrate (CaSO _4. 2H _2 O) and Sn in the form of oxides. These oxides, however, are useful especially when these are in the form of tin dioxide-coated CaCO _3 shell-core structures—having demonstrated flame retardant and smoke suppressant properties. On the other hand, calcite was successfully transformed into strontium carbonate (SrCO _3 ) or strontianite through the cation exchange reaction. X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) were used to observe the resulting materials and understand the transformation of both Placuna placenta (or Capiz) shells and single-crystal calcite from the ion-exchange reactions. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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