Title : Tuning the photocatalytic activity of cerium oxide
Abstract:
facial one-step synthesis procedure was applied to prepare porous sponge-like ceria (CeO2) and manganese doped porous ceria (Mn-CeO2) with different Mn content (1 to 10%) to improve its photocatalytic performance. The synthesis was performed by were prepared by using a flash combustion technique (one-step) process and water only as a solvent. Moreover, citric acid was utilized as a fuel in an aqueous medium, and the overall synthesis mixture was dried at 100 °C overnight and then calcinated at 550 °C for 3 h. The obtained final solid product was characterized by inductively coupled plasma (ICP), X-ray powder diffraction (XRD), diffuse reflectance ultraviolet visible spectroscopy (DR-UV-Vis), and scanning electron microscopy (SEM), which was coupled with Energy Dispersive X-Ray Analysis (EDX), N2 sorption measurement, high resolution transmission electron microscopy (HR-TEM), and photoluminescence (PL) analysis. The characterization data showed that the nanoparticles of the porous ceria were formed with a three-dimensional pore system. Moreover, the measured surface area of the porous sample was eight times higher than the commercially available ceria and showed that Mn ions were totally incorporated into the framework of ceria up to the applied loading. Under visible light illumination, the photocatalytic activity of the prepared samples was tested in the decolorization reaction of methyl green (MG) dye (wavelength greater than 425 nm). The obtained results showed that the photocatalytic activity of porous ceria was higher than that of the commercial sample and showed that increasing Mn content improved the photocatalytic activity of ceria. The sample with a Ce/Mn ratio of 10 performed 1.8 times better than bare porous ceria. The second application was the photocatalytic elimination of a gaseous mixture consisting of five short chain hydrocarbons (C1–C3). Finally, the reusability of the best-performing sample was investigated in four consecutive runs without treatment, and slight deactivation (less than 9%) was monitored after the fourth run.
