Oxygen-deficient lanthanum doped cerium oxide nanoparticles for potential applications in spintronics and photocatalysis

Abstract

In this report, we have investigated oxygen-deficient lanthanum (La) doped cerium oxide (CeO2) nanoparticles for their potential applications in spintronics and photocatalysis. XRD measurements indicate lattice expansion with an increase in La content in the host matrix. TEM images show that morphology of cerium oxide nanoparticles transformed into grain-like structures with La3+ ion concentration. The increase in defects with La content was confirmed by spectroscopic techniques viz. Raman and X-ray photoelectron spectroscopy (XPS). XPS revealed the introduction of new networks La3+-O-Ce3+ and La3+-O-Ce4+ that enhanced the vacancy defects. The defects in the form of oxygen vacancies played a vital role in increasing the net magnetization that can be explained by F-center exchange mechanism. Further, the formation of vacancy defects were responsible for the reduction in band gap up to La 8% (Eg = 3.08 eV) as compared to non-substituted CeO2 (Eg = 3.21 eV). Henceforth, it can be concluded that defects in the form of oxygen vacancies are key component for the enhancement in magnetic properties and photocatalytic efficiency towards the degradation of Rose Bengal dye.