共沉淀法合成La_(2)Ce_(2)O_(7)粉体及其作为防晒剂的性能研究  

A Study of the Synthesis of La_(2)Ce_(2)O_(7) Powder by Co-precipitation Method and Its Properties as Sunscreen Agent

作　　者：夏小洁 孙玥 金星 冉松林[1,2] XIA Xiaojie;SUN Yue;JIN Xing;RAN Songlin(Key Laboratory of Metallurgical Emission Reduction&Resources Recycling,Ministry of Education,School of Materials Science&Engineering,Anhui University of Technology,Maanshan 243032,China;Advanced Ceramics Research Center,School of Materials Science&Engineering,Anhui University of Technology,Maanshan 243032,China)

机构地区：[1]安徽工业大学冶金减排与资源综合利用教育部重点实验室,安徽马鞍山243032 [2]安徽工业大学材料科学与工程学院先进陶瓷研究中心,安徽马鞍山243032

出　　处：《安徽工业大学学报(自然科学版)》2025年第2期143-150,共8页Journal of Anhui University of Technology(Natural Science)

基　　金：国家自然科学基金项目(52072003)。

摘　　要：针对高温固相法合成La_(2)Ce_(2)O_(7)粉体存在合成温度高、反应时间长等问题,以La(NO_(3))_(3)·6H_(2)O和Ce(NO_(3))_(3)·6H_(2)O为金属离子源,氨水为沉淀剂,采用共沉淀法成功合成La_(2)Ce_(2)O_(7)粉体。采用同步热分析仪、傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)以及扫描电子显微镜(SEM)研究前驱体的转化过程、产物的物相演变和形貌特征;利用紫外–可见光分光光度计测试分析产物的紫外吸收性能;通过光催化降解罗丹明B染料实验评价分析材料的光催化活性。结果表明:La_(2)Ce_(2)O_(7)粉体在300~700℃温度范围处于结晶阶段,500℃时即可观察到明显的细小颗粒或絮状产物,与高温固相法(合成温度1400℃)相比,共沉淀法的合成温度降低了900℃,500℃下合成的La_(2)Ce_(2)O_(7)粉体具有明显的微孔结构,且分布均匀,禁带宽度更低,紫外吸收性能更佳,较高温固相法提高了21.7%。由于La2O_(3)的引入有效抑制了纯CeO_(2)中活性氧自由基(ROS)的产生,使得材料的光降解率不随光照时间延长而持续下降,最终稳定在15%左右。本研究证明,共沉淀法不仅能显著降低La_(2)Ce_(2)O_(7)粉体的合成温度和反应时间,还能有效优化其作为防晒剂应用的紫外吸收性。To address the issues of high synthesis temperature and prolonged reaction time in the high-temperature solid-phase synthesis of La_(2)Ce_(2)O_(7)powder,using La(NO_(3))_(3)·6H_(2)O and Ce(NO_(3))_(3)·6H_(2)O as metal ion sources with ammonia water as the precipitant,La_(2)Ce_(2)O_(7)powder was successfully prepared by co-precipitation method.The synchronous thermal analyzer,Fourier transform infrared(FTIR)spectrometer,X ray diffractometer(XRD)and scanning electron microscopy(SEM)were employed to investigate the precursor transformation process,phase evolution,and morphological characteristics of the products.UV–Vis spectrophotometry was used to analyze the UV absorption properties,while photocatalytic activity was evaluated through Rrhodamine B degradation experiments.The results show that La_(2)Ce_(2)O_(7)powder undergoes crystallization between 300–700℃,with distinct fine particles or flocculent products appearing at 500℃.Compared to the high-temperature solid-state method(synthesis temperature of 1400℃),the co-precipitation approach reduces the synthesis temperature by 900℃.The La_(2)Ce_(2)O_(7)powder synthesized at 500℃exhibits well-distributed micropores,narrower bandgap,and significantly enhanced UV absorption performance-showing a 21.7%improvement over the solid-state method.The incorporation of La2O_(3) effectively suppressed the generation of reactive oxygen species(ROS)in pure pure CeO_(2),resulting in a stabilized photodegradation rate that remained constant at approximately 15%without further decrease upon prolonged irradiation.This study demonstrates that the co-precipitation method not only substantially reduces the synthesis temperature and reaction time for La_(2)Ce_(2)O_(7)powder production,but also effectively optimizes its UV absorption properties for sunscreen applications.

关 键 词：La_(2)Ce_(2)O_(7) 共沉淀法 防晒剂 紫外吸收性能 光催化活性 降解率 CeO_(2) 

分 类 号：X51[环境科学与工程—环境工程]