柠檬酸络合法制备La_2CuO_4纳米晶  

Preparation of La_2CuO_4 Nanocrystallites by Citric Acid Chelating Process

作　　者：李意峰[1] 黄剑锋[1] 曹丽云[1] 吴建鹏[1] 

机构地区：[1]陕西科技大学教育部轻化工助剂化学与技术重点实验室,西安710021

出　　处：《无机化学学报》2011年第11期2157-2161,共5页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.50942047);陕西省自然科学基金(2010JM6001);陕西科技大学科研创新团队基金(TD09-05);陕西科技大学研究生创新基金资助项目

摘　　要：以硝酸镧和硝酸铜为起始原料,柠檬酸为络合剂,采用溶胶-凝胶法制备了La2CuO4纳米晶。通过X射线衍射、场发射扫描电子显微镜、透射电子显微镜研究了柠檬酸的加入量对La2CuO4纳米粉体相组成、显微结构的影响,并采用Kissinger方法研究了La2CuO4纳米晶的合成活化能。结果表明:600℃煅烧保温2 h后,可获得单一物相的La2CuO4,晶粒为类钙钛矿型结构,晶粒尺寸为60～80 nm,分布集中;在制备过程中提高柠檬酸的加入量能够降低La2CuO4晶体的合成活化能,当柠檬酸与溶液中阳离子(La3+和Cu2+)的物质的量的比由1∶1增加至1.5∶1时,La2CuO4纳米晶的合成活化能由147.0 kJ.mol-1降低到133.4 kJ.mol-1。La2CuO4 nanocrystallites were prepared via a sol-gel process using lanthanum nitrate and cupric nitrate as raw materials and citric acid as complexing agent.The influences of citric acid amount on the phase composition and microstructure of the powders were characterized by XRD,FESEM and TEM.The preparation activation energy of La2CuO4 crystallites was investigated by Kissinger method.The results show that pure La2CuO4 nanocrystallites can be obtained after calcining at 600 ℃ for 2 h and exhibit an perovskite-like type structure,the grain size is 60～80 nm with narrow distribution.The preparation activation energy of La2CuO4 nanocrystallites can be decreased by elevating the amount of citric acid,with the increase of the molar ratio of citric acid to cations（La3＋ and Cu2＋） in the solution from 1∶1 to 1.5∶1,the preparation activation energy decreases from 147.0 kJ·mol-1 to 133.4 kJ·mol-1.

关 键 词：铜酸镧 柠檬酸 合成活化能 纳米晶 溶胶-凝胶 

分 类 号：O614.331[理学—无机化学] TB34[理学—化学]