Enhanced Photocatalytic Activity of Manganese-Doped Cerium Oxide Nanoparticles under Visible and UV Irradiation

Manganese-doped cerium oxide nanoparticles were synthesized in different concentrations (3 and 5 mol %), by simple aqueous coprecipitation method by adding manganese chloride to cerium(III) nitrate hexahydrate.The synthesized nanoparticles were characterized by powdered XRD measurements, EDAX, SEM, TEM and UV-visible spectroscopic techniques.Powder X-ray diffraction results revealed the phase purity with fluorite structure.EDAX confirmed the doping of manganese in the cerium oxide lattice at different concentrations.Spherical shape of the synthesized particles with fair agglomeration was revealed by SEM analysis.The morphology was further confirmed by TEM analysis which asserted the average particle size to be 12-15 nm.Remarkable red shift in the band gap of manganese-doped cerium oxide nanoparticles was observed by UV-visible spectroscopic analysis.Photocatalytic activity of the pure and Mn-doped CeO2 nanoparticles was evaluated by studying degradation of anthraquinone dye remazol brilliant blue R under visible and UV irradiation.The 3 mol % Mn-doped CeO2 nanoparticles exhibited 61.7 and 62.4% photocatalytic efficiency under visible and UV irradiation, respectively and 5 mol % Mn-doped CeO2 nanoparticles showed photocatalytic efficiency of 62.4 and 67.7 % under visible and UV irradiation, respectively.The present study suggests a facile method to narrow the band gap of cerium oxide nanoparticles and making it more efficient photocatalyst by doping it with Mn ions.