纳米CeO2光催化材料合成与性能研究

AbstractDue to the rapid development of industry and other factors,the problem of waterpollution has become more and more serious.How to efficiently degrade organic dyes andpollutants produced in various production processes has become a major problem hinderingthe sustainable development of human beings.Photocatalysis,which has the advantages ofnon-toxic,pollution-free and mild reaction conditions,is an effective method to degradeorganic pollutants by light energy.Nano-oxide semiconductor is one of the most effectivephotocatalysts for photocatalytic degradation.Rare earth oxide semiconductor cerium dioxide(CeO2)has the advantages of abundant reserves,low price,stable physical and chemicalproperties.Since Ce element has a special 4f electron orbital,REDOX electron pairs ofCe3/Ce#exist in CeO2 and have a strong REDOX capacity,which is of great help to improvethe photocatalytic performance.Due to the presence of Ce3 and size effect,a large number of oxygen defects exist inCeO2 nanomaterial,which makes it have high photocatalytic performance.In this paper,Ce-MOF was prepared by using the synthesis route of metal organic framework and theporous CeO2 photocatalytic materials with large area were obtained,so as to improve the lightabsorption range and the efficiency of photocatalytic degradation of organic pollutants.Themain research contents and conclusions are as follows:1.Firstly,Ce-MOF was synthesized by solvent heat method using Ce(NO3)36H2O ascerium source,polyvinylpyrrolidone and citric acid as collaborative template.Ce-MOFspherical nanomaterials with regular morphology were prepared by controlling the amount ofcitric acid.Subsequently,by calcining the prepared Ce-MOF in air,porous nano-CeO2photocatalyst with high specific surface area and porosity were obtained.XRD analysis showsthat the crystallinity of the sample is high and no impurity peaks was found.By SEMobservation,it was found that the morphologies of the samples were different under differentcitric acid dosage.When the citric acid dosage was 0.5g,the obtained sample had the bestmorphology,which was a regular sphere with a particle size of 0.6um to 0.8um.By BET test,it was found that sample had a specific surface area of 43.49m2/g and a concentratedmesoporous aperture of 2.45nm.2.In order to further explore the physicochemical properties and photocatalyticproperties of the porous nano CeO2 photocatalyst samples,the structure and properties of thesamples were characterized and analyzed by various testing methods.Through X-rayphotoelectron spectroscopy and photoluminescence spectroscopy,it was found that Ce3accounted for 66.395%of the sample,and there were a large number of oxygen vacancies.The ratio of oxygen vacancies to lattice oxygen was about 49.53%.According to the analysis