Photoluminescence, photocatalysis and Judd-Ofelt analysis of Eu super(3+)-activated layered BiOCl phosphors

Eu super(3+)-activated layered BiOCl phosphors were synthesized by the conventional solid-state method at relatively low temperature and shorter duration (400 degree C for 1 h). All the samples were crystallized in the tetragonal structure with the space group P4/nmm(no. 129). Field emission scanning electron microscopy (FE-SEM) studies confirmed the plate-like morphology. Photoluminescence spectra exhibit characteristic luminescent super(5)D sub(0) arrow right super(7)F sub(J) (J= 0-4) intra-4f shell Eu super(3+) ion transitions. The electric dipole transition located at 620 nm ( super(5)D sub(0) arrow right super(7)F sub(2)) was stronger than the magnetic dipole transition located at 594 nm ( super(5)D sub(0) arrow right super(7)F sub(1)). The evaluated Commission International de l'Eclairage (CIE) color coordinates of Eu super(3+)-activated BiOCl phosphors were close to the commercial Y sub(2)O sub(3):Eu super(3 +) and Y sub(2)O sub(2)S:Eu super( 3+) red phosphors. Intensity parameters ( Omega sub(2), Omega sub(4)) and various radiative properties such as transition probability (A sub(tot)), radiative lifetime ( tau sub(rad)), stimulated emission cross-section ( sigma sub(e)), gain bandwidth ( sigma sub(e) Delta lambda sub(eff)) and optical gain ( sigma sub(e) tau sub(rad)) were calculated using the Judd-Ofelt theory. The experimental decay curves of the super(5)D sub(0) level in Eu super(3+)-activated BiOCl have a single exponential profile. In comparison with other Eu super(3+) doped materials, Eu super(3+)-activated BiOCl phosphors have a long lifetime ( tau sub(exp)), low non-radiative relaxation rate (W sub(NR)), high quantum efficiency ( eta ) and better optical gain ( sigma sub(e) tau sub(rad)). The determined radiative properties revealed the usefulness of Eu super(3+)-activated BiOCl in developing red lasers as well as optical display devices. Further, these samples showed efficient photocatalytic activity for the degradation of rhodamine B (RhB) dye under visible light irradiation. These photocatalysts are useful for the removal of toxic and non-biodegradable organic pollutants in water.