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. X-ray 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 photo-catalytic 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 photo-catalyst 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.