Synthesis And Properties Of Rare Earth Ions-doped Metal Cyanamide Low-dimensional Nanostructures

Metal cyanamide,as an important luminescent matrix,has drawn more and more attention of researchers owing to their unique structures.Nowadays,some metal cyanamide powders,such as MgCN₂,SrCN₂,Cr2?CN₂?3,Ln2O2CN₂?Ln = Y,Ho,Er,Yb?,RE2O2CN₂:Eu³⁺?RE = La,Gd?,have been successfully obtained by high temperature solid state method,organic metal precursor method,sol-gel method,etc.However,there is only a few reports on the fabrication of metal cyanamide low-dimensional nanostructures,and more work needs to be done.Electrospinning is a simple and effect method to prepare low-dimensional nanostructures.Hence,fabrication of metal cyanamide low-dimensional nanostructures by electrospinning remains a meaningful subject of study.In this dissertation,La₂O₂CN₂:RE³⁺?RE = Tm,Pr,Yb/Tm?nanofibers and nanobelts,?-SrCN₂ nanoparticles,?-SrCN₂ namosheets and CaCN₂ monodisperse nanoparticles were fabricated via electrospinning technique combined with cyanamidation method.The samples were characterized by XRD,SEM and PL methods.The results show that La₂O₂CN₂:RE³⁺ nanofibers and nanobelts are pure tetragonal system.The mean diameter of La₂O₂CN₂:RE³⁺ nanofibers and width of nanobelts are,respectively,74-109 nm and 1.5-2.0 ?m.La₂O₂CN₂:Tm³⁺,La₂O₂CN₂:Pr³⁺ nanofibers and nanobelts possess excellent down conversion luminescent properties,and La₂O₂CN₂:Yb³⁺/Tm³⁺ nanofibers and nanobelts exhibit obvious up conversion luminescent properties while nanofibers have higher luminescent intensities than nanobelts.The ?-SrCN₂ and ?-SrCN₂ are pure system,and the mean size are 149-209 nm.CaCN₂ monodisperse nanoparticles are pure trigonal system,and the mean size is about 127 nm.Moreover,possible formation mechanisms of metal cyanamides low-dimensional nanostrctures are also presented.These new findings have provided the novel research idea for the future study of metal cyanamides.