Synthesis, characterization, and performance evaluation of pristine and cerium-doped WO3 nanoparticles for photodegradation of methylene blue via solar irradiation

In this study, an effective photodegrading properties of WO3 nanoparticles has been enhanced by doping with cerium. To achieve our goal pristine and Ce-doped WO3 nanoparticles were prepared by a simple and cost effective co-precipitation route. Characterization of all the specimens were conducted which showed that there were no noticeable structural changes. WO3 retained its monoclinic structure even after doping with (3%, 5%, 8%, 10%) cerium which was also confirmed with X-ray diffraction (XRD) and Raman spectroscopy. In addition, XRD and Fourier transform infra-red spectroscopy also confirm that no new phases were formed in doped specimens. XRD also depicts that minimum crystallite size is achieved at 3% cerium doping. Scanning electron microscope images show decrease in particle size initially at 3% cerium doping, that is, 80 +/- 2.5 nm. In contrast, further increase in doping percentage increases crystallite and particle sizes. Additionally, defect generation increased at lower doping percentage 3%. In contrast, further increase in dopant (5%, 8%, 10%) caused defect annihilation process to dominate over defect generation. C/C-o ratio and rate constant (K-MB) values suggest that maximum degradation of methylene blue will occur at 3% cerium doping due to increase in crystalline defects. Ultraviolet visible Spectroscopy further validates C/C-o ratio and degradation rate constant values by showing drastic decline in peak intensity at 3% cerium doping. Therefore, 3% cerium-doped WO3 is more effective photocatalyst to degrade methylene blue in comparison to most of the previously used photocatalysts. The prepared cerium-doped WO3 nanoparticles as a sun light driven photocatalyst, may be utilized for industrial wastewater purification.