Substitution of Ca2+ in Calcite by Sn2+ and Sr2+ cations through ion exchange characterized by X-ray absorption and photoelectron spectroscopies

Autor: Prae Chirawatkul, Jonathan B. Junio, Marlon T. Conato, Candy C. Mercado
Rok vydání: 2021
Předmět:
Zdroj: MRS Advances. 6:342-349
ISSN: 2059-8521
DOI: 10.1557/s43580-021-00061-w
Popis: Tin (Sn2+) and strontium (Sr2+), two potential alternatives to lead (Pb2+) in perovskite formation, were explored in transforming calcium carbonate (CaCO3) into a leaving group in a cation exchange reaction. This is the first part of a sequential ion exchange process in transforming calcite into a Pb-free perovskite material for perovskite solar cell applications. Calcite, a polymorph of CaCO3, was successfully transformed into strontianite (SrCO3) through a cation exchange reaction. In the Sn substitution reaction on the other hand, no SnCO3 formation was noted. Instead, oxides of Sn were formed. The wider spaces in between Ca2+ cations in (100) orientation account for the higher atomic Sn2+ and Sr2+ concentrations as compared to (001) orientation, where the cation movement is restricted. X-ray absorption and photoelectron spectroscopies were used to investigate the ion-exchange transformation of calcite towards the formation of an intermediate carbonate material. Graphic abstract
Databáze: OpenAIRE