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

Abstract

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 (Eg) 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.