Erbium-doped oxygen deficient cerium oxide: bi-functional material in the field of spintronics and photocatalysis

Present work is focused on the study of Er-doped CeO2 nanoparticles for their potential applications in the field of spintronic devices and photocatalysis. X-ray diffractometer (XRD) shows the lattice expansion with an increase in Er concentration that leads to tensile stress in the lattice system. High-resolution transmission electron microscopy (HRTEM) reveals that (111) and (200) are dominating planes with narrow particle size distribution in accordance with XRD. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) elucidate the vacancy defects which increase with Er3+ ions concentration. New originated Frohlich-like (FL) mode is present in Raman spectra of all the samples which contribute to the defects in the host lattice structure. UV-Vis. measurements show decrease in bandgap energy (E-g) with Er content up to 8% and then increment due to impact of vacancy defects. Defect-based room temperature ferromagnetism (RTFM) has also been briefly discussed on the basis of new network formation like Ce3+-O-Ce4+, Ce4+-O-Er3+ and Ce3+-O-Ce3+. Photocatalytic degradation of rose bengal (RB) dye using Er incorporated CeO2 photocatalysts has been demonstrated under the influence of UV light. The results elucidated that incorporation of Er3+ ions enhances the reduction of Ce4+ to Ce3+ ionic state that ultimately leads to increase in vacancy defects which improve the photocatalytic efficiency up to 91.3% for Er 8 photocatalyst and decreases afterwards.