Preparation And Their Photocatalytic Activities Of CeO₂ And Modified Materials

Energy shortage and environmental pollution have become serious problems that we are facing at this stage owing to rapid development of industrialization. Therefore, the important is how to solve the problems effectively. The using of photocatalytic performance of semiconductor photocatalytic material is an effective measure to resolve the problems at present. Cerium, as one of the most abundant rare earth elements, performances of its oxide is similar to titanium dioxide, which is a typical photocatalyst. However, the using of cerium dioxide is limited because of its wide bandgap. Thence, this study expounds that using different reagents to modify cerium dioxide to enhance the photocatalytic activity, we and study the impact of morphology, structure and composition of modified samples. The main achievements are listed as following:(1) CeO2 nanoparticles of face-centered cubic fluorite structure have prepared by low temperature combustion method. Moreover, utilizing the same method to prepared CeO2 doped with F. And the photocatalytic activity of the doped samples can be controlled by adjusting the amount of sodium fluoride. The methylene blue degradation efficiency plots certificates that appropriate amount of sodium fluoride doped samples shows the strongest photocatalytic activity.(2) By adjusting the molar ratio of fluorine and cerium atoms, we get pure CeO2, pure CeF3 and CeO2/CeF3 composite nanoparticles. And the photocatalytic activities under ultraviolet of prepared samples have corresponding changes. The results of experiments show that the photocatalytic activity of pure CeF3 prepared by combustion better than pure CeO2 and the composites prepared by the same method. Furthermore, by the first principle calculation of CeO2 and CeF3, we explain the reason of the high photocatalytic activity of CeF3 than CeO2.This work confirms the potential application of CeF3 as a photocatalyst.(3) Ceria modifed materias are prepared via combustion with different amounts of phosphoric acid. With the increase of the amount of phosphotic acid, the morphologies, surface areas and photocatalytic activities of prepared samples have changes. And the results of experiments indicate that the phtocatalytic activity of modified samples with phosphoric acid better than pure CeO2.