Structural, Optical, and Magnetic Studies of Palladium (Pd) Doped Cerium Oxide (CeO2) Nano Particles

In this study, an innovative method is used in the synthesis of Pd-doped CeO2 nanoparticles through co-precipitation, with a focus on an extensive characterization of their structural, optical, and magnetic properties. Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirm a cubic structure via XRD and spherical morphology through SEM, respectively. Energy-dispersive X-ray spectroscopy (EDAX) further corroborated the presence of Pd, Ce, and O constituents in these nanoparticles. An intriguing finding revolves around the optical band gap, as Pd concentration increased, the optical band gap diminished from 2.92 eV to 2.25 eV, spanning from Pd0.00 Ce100O2 to Pd5.0 Ce95.0O2. Chemical bonding analysis via X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of Ce, O, and Pd elements with distinct binding energies: Ce 3d at 850–920 eV, O1s at 530 eV, and Pd 3d at 360 eV. Additionally, Raman spectra displayed a prominent peak at 464.01 cm-1, indicating a slight deviation from the bulk CeO2's typical Raman active mode at 459 cm-1, hinting at potential phonon confinement effects due to reduced particle size. Besides, magnetic studies unveiled enhanced properties in 5% Pd-doped CeO2, transitioning from diamagnetic to paramagnetic behaviour.