Antenna Effect in Highly Luminescent Eu~(3+)Anchored in Hexagonal Mesoporous Silica

摘要

A route for coordination of Eu~(3+)by dibenzoylmethane(DBM)covalently bonded inside hexagonal mesoporous silica was established here to produce the highly luminescent nanomaterial SiDBM-Eu-(DBM)2.Thermogravimetry,luminescence,X-ray diffraction,N2 adsorption,FTIR,FTRaman,~(29)Si NMR,and ~(13)C NMR in solid-state techniques were used to characterize SiDBM-Eu(DBM)2.The ~(29)Si NMR spectrum proved that the DBM was covalently bonded to a silica framework.Thermogravimetric and titration data showed the 6.4 x 10~(-2)mmol of Eu~(3+)per gram of silica,and each Eu~(3+)is coordinated by three DBMs in SiDBM-Eu(DBM)2.SEM images confirmed that this material is formed by nanoaggregates with 200 nm diameter.N2 adsorption isotherms showed the SiDBM-Eu(DBM)2 complex with 800 m~2 g~(-1)and 6.4 nm of porous diameter,characterizing mesoporosity of this nanomaterial.SiDBM-Eu(DBM)2 showed an efficient DBM to Eu~(3+)intramolecular energy process,namely,antenna effect,which favored a highly luminescent behavior in this modified hexagonal mesoporous silica.