Photoluminescence, structural, optical, ferroelectric and photo-catalytic properties of magnetically separable CdO/CoFe2O4 hetero-junction

A series of cobalt ferrite/cadmium oxide (CFO/CO) hetero-junctions were synthesized via an ultra-sonication approach. The compositions were examined based on ferroelectric, optical and photo-catalytic properties. Xray diffraction (XRD), UV-visible (UV-Vis) spectroscopy and photo-luminescence (PL) were employed for the characterization of the prepared materials. XRD analysis confirmed a distorted cubic phase with space group fm3m and grain size was in 17.6-19.2 nm range. The ferroelectric parameters were enhanced significantly by the addition of CO (CdO) into the CFO (CoFe2O4) crystal lattice. The band-gap energy was decreased significantly of hetero-junctions from 3.29 to 2.54 eV. The enhanced ferroelectric polarization with low band-gap energy boosts their ferroelectric and optical responses. A reduction in PL intensity was observed in hetero-junctions. The photocatalytic activity (PCA) of CFO and cobalt ferrite/cadmium oxide (1-4) hetero-junctions CFO/CO (1-4) was examined by photo-degradation of Methylene Blue (MB) dye under visible light exposure. The CFO/CO4 photocatalyst exhibited superior PCA of 92% within 90 min irradiation. Additionally, photo-catalyst dose and pH effect on the kinetics of MB dye degradation was also examined. Superior PCA of CFO/CO4 in comparison to pure CFO makes this material a promising candidate for the removal of hazardous dyes in effluents under visible light irradiation.