摘要
采用微波水热法合成不同孔径的介孔分子筛(mesoporous molecular sieve,MCM-41),通过Pechini溶胶-凝胶法合成Eu-MCM-41,并将EuPO4:Zn晶体沉积在MCM-41表面,研究介孔材料孔径对荧光强度的影响。结果表明:EuPO4:Zn无荧光,Eu-MCM-41发出很强的蓝光(468nm)和橙光(593nm);当EuPO4:Zn颗粒的孔径小于3.1nm时,荧光强度随孔径的增大而增加,大于3.1nm时,则相反。影响铕离子(Ⅲ)的发光强度主要有量子点的密度、铕离子中心的分裂和量子点的集聚程度,并且都与MCM-41的孔径有关,在改变选择规则的同时也影响磁偶极子,尤其使得f→f转换的量子跃迁成为可能。
A series of mesoporous molecular sieves （MCM-41） with different pore sizes were synthesized through hydrothermal method under microwave irradiation. Europium-MCM-41 composites were obtained through Pechini sol–gel process. Crystals of EuPO 4 ：Zn were deposited on MCM-41. Effects of pore sizes on photoluminescence （PL） were investigated. Investigation of PL spec- tra indicates that EuPO 4 ：Zn particles are non-fluorescent. However, the Eu-MCM-41 possesses strong blue （468 nm） and orange （593 nm） PL emission. The PL intensity of the Eu-MCM-41 increases along with the pore size until aperture≤3.1 nm, and then gradually decreases as aperture continued to increase. There are three factors responsible for the PL intensity of Eu（Ⅲ） ions： density of quantum dots （QDs）, splitting of centers of Eu（Ⅲ） ions, and degree of agglomeration of QDs. These factors are related to the pore size of the MCM-41, which change the selection rules and affect magnetic dipole-allowed transition probabilities of particular f→f transitions.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2011年第12期1981-1987,共7页
Journal of The Chinese Ceramic Society
基金
重庆大学研究生创新基金(201005A1A0010332)
中央高校基本科研业务费(CDJXS10221136)资助项目
关键词
介孔分子筛
铕(Ⅲ)
孔径
荧光
mesoporous molecular sieves
europium
pore size
photoluminescence
