Effect of Temperature on the Structural and Optical Characterization of Mn-doped Cerium Oxide Nanoparticle as a Photocatalyst
Jaya Mootheadath Soney and Dhannia Thankappan
This paper presents a facile, cost-eﬀective, and environment-friendly synthesis of Mn-doped cerium oxide nanoparticles at different concentrations via co-precipitation with microwave irradiation method, using CeCl3.7H2O, MnCl2.4H2O, and ovalbumin in an aqueous medium. The effect of annealing temperatures on the structural and optical properties of the as-prepared samples are studied. XRD, SEM, and TEM results confirm the spherical also rectangular rod-like polycrystalline fluorite structure for all the samples. Crystallite size is found to decrease with an increase in Mn concentration. Raman studies show a redshift in the Raman active mode around 460cm-1 . UV-Vis analysis shows good absorption in the ultraviolet region for all samples. Bandgap energy of the as-prepared sample (3.2eV) is found to decrease with an increase in annealing temperature and also with doping concentration. Oxygen deficiency and lattice distortion of the as-prepared and annealed samples at different dopant concentrations are studied by Photoluminescence spectra. The valence states and the surface chemical composition of the as-prepared Ce0.97Mn0.03O2-δ are studied using XPS analysis. From the results, Mn-doped CeO2 renters prospects of application as a promising photocatalyst.
Keywords: CeO2, CeCl3.7H2O, MnCl2.4H2O, XRD, SEM, and TEM