Preparation Of Ce/Sm-O-S Composite Compound And Study On Its Light-shielding Performance

The currently used ultraviolet absorbers are mainly divided into organic and inorganic types.Organic UV absorbers have problems such as skin irritation,easy aging,poor stability,and toxicity,while inorganic UV absorbers also have the disadvantage of narrow UV shielding range.This paper is based on the fact that cerium oxide has a certain UV shielding function.In order to broaden its UV shielding range,a Ce/Sm-O-S composite compound is prepared by a wet method,and Sm and S are used to improve the UV shielding performance of the product.This thesis uses cerium nitrate,samarium nitrate,sodium thiosulfate and sodium hydroxide solution as raw materials,and PVP as template.Through orthogonal experiment and single factor experiment,the precursor is prepared by the method of aqueous solution precipitation,and then calcined to obtain Ce/Sm-OS compound compound.The product has been tested by UV-Vis,XRD,XPS,and other tests to investigate the ratio of samarium-cerium-sulfur,solution pH,solution temperature,stirring time,roasting temperature,roasting time to the product’s UV shielding performance,optical band gap,crystallinity,and surface element content.And the influence of microscopic morphology.The experimental results show that when the molar ratio of sulfur to samarium-cerium is 2:1,the molar ratio of samarium-cerium is 1:1,the pH of the solution is 12,the solution temperature is 30℃,the stirring time is 4h,the roasting temperature is 500℃,and the roasting time The UV shielding effect of the samples prepared from 3h to 5h is relatively good,but considering the factors of energy saving and environmental protection,the 3h roasting time is selected,the TUVA value is 3.80%,and the TUVB value is 2.35%.The XRD test shows that the phases are mainly Sm2O2S,Sm2O3,and CeO1.66.As the molar ratio of samarium-cerium decreases,the pH value of the solution increases,and the calcination time is prolonged,the crystallinity of the product increases.As the stirring time increases,the crystallinity of the product first increases and then decreases.Combined with the results of ultraviolet analysis,it can be seen that the ultraviolet shielding effect is better when there are Sm2O2S and Sm2O3 phases in the product.The XPS test shows that the higher pH value of the solution during the preparation process is conducive to the formation of Ce4+,and more rare earth oxides and rare earth sulfur oxides will be formed.In addition,the molar ratio of cerium in the raw materials increases and the solution pH value is higher.,The product has a higher proportion of lattice oxygen Oβ,and the product shows that the UV shielding effect is better when the content of Ce4+ ions and lattice oxygen Oβ is higher.The SEM test shows that the UV shielding effect is better when the microscopic morphology of loose and porous fine strip particles appears on the surface of the sample.