EFFECTS OF Eu-DOPING SITE ON STRUCTURAL AND PHOTOLUMINESCENT PROPERTIES OF CaTiO3 PARTICLES

In this paper, Eu3+-doped CaTiO3 (CTO) nanoparticles were prepared by a sol-gel method. Three different charge compensation mechanisms were realized by substituting Eu ion at different sites. (i) Ca site substitution with Ca vacancy compensation (CTO-A); (ii) Ti site substitution with O vacancy compensation (CTO-B); (iii) simultaneous substitution at both Ca and Ti sites with self-compensation (CTO-AB). Strongly related to the site substitution, the photoluminescent (PL) intensities were increasing in the sequence of CTO-B> CTO-AB> CTO-A. The absorbance spectra analysis of pure CTO nanoparticles showed absorption in the UV light region, while the absorption of Eu-doped CTO samples exhibited the blue shift owing to the presence of Eu3+. Moreover, the photocatalytic activities of samples for decomposing dyes were reverse to the sequence of PL intensities. The PL properties and photocatalytic activity of the Eu3+-doped CTO nanoparticles were thus discussed in detail from the viewpoints of the microstructures and charge transfer-related processes.