络合沉淀制备纳米氧化铈及其紫外屏蔽性能与表征  

Preparation of Nanometer Cerium Oxide by Complex Precipitation and Its Ultraviolet Shielding Performance and Characterization

作　　者：刘杨 边雪 李艳平 杨玉明 吴文远 Liu Yang;Bian Xue;Li Yanping;Yang Yuming;Wu Wenyuan(College of Metallurgy,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学冶金学院,辽宁沈阳110819

出　　处：《稀有金属》2022年第10期1314-1321,共8页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51774070)资助

摘　　要：为了制备具有较佳紫外屏蔽性能的氧化铈,采用柠檬酸络合沉淀法制备了纳米氧化铈,研究沉淀pH及柠檬酸(A)与铈(Ce)摩尔比(n_(A)∶n_(Ce))的变化对样品紫外屏蔽性能的影响。X射线衍射(XRD)和扫描电镜(SEM)测试结果表明:样品由CeO_(2)和Ce_(11)O_(12)两种物相组成,定铈分析表明样品中含有Ce^(3+),从而引起了XRD衍射峰的宽化。制备的氧化铈晶粒尺寸为5.9~7.7 nm,微观形貌为球形纳米颗粒团聚物,样品XRD图像中最强峰与标准卡片相比右移,结合晶粒尺寸减小可知氧化铈的晶格内部产生氧空位缺陷。当pH=4.5,n_(A)∶n_(Ce)为0.75时,样品晶粒尺寸达到最小值5.9 nm,Ce^(3+)质量分数达到最高值62.98%,此条件样品紫外屏蔽性能最优,即中波紫外线平均透过率(TUVB)最低为2.2%和长波紫外线的平均透过率(TUVA)最低为6.3%,是性能较佳的紫外屏蔽剂。根据本文的研究可知,小的晶粒尺寸反映出氧化铈晶体中氧空位缺陷的产生,而缺陷和Ce^(3+)的形成使禁带宽度减小,提高了紫外屏蔽性能。Inorganic ultraviolet(UV)shielding agents are widely used due to their stable and non-toxic advantages,mainly including titanium oxide,zinc oxide and cerium oxide.CeO_(2) nanoparticles have low band gap,good UV shielding ability,and can buffer oxidation and reduce DNA damage through their Ce^(3+)/Ce^(4+) valence changes,thus becoming an important tool for skin cancer prevention.In this paper,by changing the preparation conditions,a sample with better UV shielding medium and long wavelengths was found.The citric acid complex precipitation method is a main method for the preparation of metal oxide nanoparticles,and the process is simple.The purpose of this paper was to prepare cerium oxide with small grain size by lemon complex precipitation method,and studied the single preparation conditions(pH or molar ratio of citric acid to cerium(n_(A)∶n_(Ce)))aftection on the UV shielding properties of the samples.The effect of grain size,lattice constant,product particle size(D_(50)),NaOH titration cerium citrate curve,scanning electron microscope(SEM)and other characterizations on the performance of UV medium and long wave transmittance was also studied.X-ray diffraction(XRD)and SEM test results showed that the sample was composed of CeO_(2) and Ce_(11)O_(12) phases,and the analysis of cerium showed that the sample contained Ce^(3+) ,which caused the broadening of XRD peak.The grain size of cerium oxide prepared in this paper was 5.9~7.7 nm,and the microscopic morphology was spherical nanoparticle agglomerates.From XRD pattern of the sample,the strongest peak in the XRD image of the sample was shifted to the right compared with the standard card.It was believed that the generation of oxygen vacancies caused the position of the strongest peak of the sample to shift to the high-angle direction.It could be seen that oxygen vacancy defects were generated inside the crystal lattice of cerium oxide.The lattice constant of the samples was smaller than the lattice constant of 0.54110 nm of pure stoichiometric CeO_(2) single crys

关 键 词：CeO_(2) 紫外屏蔽性能 禁带宽度 

分 类 号：TQ133.3[化学工程—无机化工] TB383.1[一般工业技术—材料科学与工程]