Group V Elements (V, Nb and Ta) Doped CeO₂ Particles for Efficient Photo-Oxidation of Methylene Blue Dye

A facile chemical route was adopted to synthesize doped CeO₂ nanoparticles (NPs) with group V elements (V, Nb and Ta) as dopants. Successful incorporation of dopants was confirmed with higher angle shift of diffraction peaks in X-ray diffraction (XRD) patterns. As a result of doping, a red shift in the absorption edge has also been observed with significant decrement in optical band gap (3.3 → 2.7 eV). Surface chemical composition was also determined with the help of X-ray photoelectron spectroscopy in which presence of dopants supported the XRD results. The associated structural modifications (O-defects) has also been determined by Raman spectroscopy in order to understand the structure-optical co-relationship. Here, the detailed photodegradation of methylene blue dye revealed the effect of individual chemical characteristics of dopants on optical and electronic transitions between valence and conduction band edges of prepared CeO₂. Further, the prepared Nb-doped CeO₂ exhibited better photocatalytic efficiency (96.8%) as compared to other samples with excellent reusability upto 4 continuous cycles.