CRYSTAL STABILITY OF THE PHASE Ca2Fe2O5 WHEN USED IN HETEROGENEOUS PHOTOCATALYSIS

CRYSTAL STABILITY OF THE PHASE Ca2Fe2O5 WHEN USED IN HETEROGENEOUS PHOTOCATALYSIS

da Silva, E. B.; Valentini, A.

Abstract:

In the field of academic study has been proposed to use Ca2Fe2O5 phase as applicable material in heterogeneous photocatalysis for degradation of organic compounds such as dyes. However, it is unclear the real applicability of this compound and little is known about the phase stability under reaction conditions. Thus, a suitable study is necessary, the interaction of this crystalline phase with carbon dioxide in aqueous solution. By means of monitoring of structural composition using X-ray diffraction, before and after various reaction conditions with the change of the bubbling gas used in the reaction system, was verified low stability of Ca2Fe2O5 phase under reaction conditions, when applied on the degradation of dyes in aqueous system. Lower conversion efficiency was observed when the process was carried out in the presence of CO2; although, the instability of Ca2Fe2O5 phase was observed also under N2, air or CO2. The degradation of the crystalline phase Ca2Fe2O5 (orthorhombic) occurs in a complete way in a short reaction time. The XRD patterns pointed out the CaCO3 phase formation, additionally suggest the formation of FeO(OH) and CaFe2O4 phases.

In the field of academic study has been proposed to use Ca2Fe2O5 phase as applicable material in heterogeneous photocatalysis for degradation of organic compounds such as dyes. However, it is unclear the real applicability of this compound and little is known about the phase stability under reaction conditions. Thus, a suitable study is necessary, the interaction of this crystalline phase with carbon dioxide in aqueous solution. By means of monitoring of structural composition using X-ray diffraction, before and after various reaction conditions with the change of the bubbling gas used in the reaction system, was verified low stability of Ca2Fe2O5 phase under reaction conditions, when applied on the degradation of dyes in aqueous system. Lower conversion efficiency was observed when the process was carried out in the presence of CO2; although, the instability of Ca2Fe2O5 phase was observed also under N2, air or CO2. The degradation of the crystalline phase Ca2Fe2O5 (orthorhombic) occurs in a complete way in a short reaction time. The XRD patterns pointed out the CaCO3 phase formation, additionally suggest the formation of FeO(OH) and CaFe2O4 phases.

Palavras-chave:

DOI: 10.5151/phypro-sic100-085

Como citar:

da Silva, E. B.; Valentini, A.; "CRYSTAL STABILITY OF THE PHASE Ca2Fe2O5 WHEN USED IN HETEROGENEOUS PHOTOCATALYSIS", p-85-85. In: Proceedings of the International Symposium on Crystallography [Blucher Physics Proceedings, v.1, n.3]. São Paulo: Blucher, 2015.
ISSN 23582359, DOI 10.5151/phypro-sic100-085