Plant-based synthesis of ceria nanoparticles and its catalytic activity

Nanotechnology is a new and emerging technology with the wealth of applications.Green synthesis route is highly relevant as it is nontoxic, decreasing/completely eliminating the use and generation of substances hazardous to human health and the environment. The biological process is a bottom-up method and green route which ituses plant, fungus, biopolymer, bacteria and, algae in the synthesis process. These materials contain some biochemical components acting as capping and/or stabilizingagents in the synthesis process. Cerium oxide is rare in the earth crust and it has wide band gap. CeO2 nanomaterials have used in a wide range of applications, such ascatalyst, gas sensors, polishing materials, solid oxide fuel cells, optical devices, etc. Here, cerium oxide nanoparticles have been synthesized in Falcaria Vulgaris leaf extract by sol-gel method. They were characterized by some physical and chemical methods such as XRD, UV-Vis spectroscopy, FT-IR, and FE-SEM. The XRD pattern confirmed the formation of cerium oxide nanoparticles with average size 19.5 nm estimated by Scherrer equation. The Ce─O vibrational stretching was observed about 410 cm-1 and UV-Visible spectrum showed a peak at 313 nm with band gap energy of 3 eV. Due to investigate catalytic properties of synthesized nanoparticles, dye degradation of methylene blue in the presence of sodium borohydride was done. The results showed that the rate of degradation increased when cerium oxide nanoparticles were added to a solution containing a mixture of methylene blue and sodium borohydride; moreover, dye was degraded 90% after 3 hours.