Preparation And Luminescence Properties Study Of Solid Multicolor Luminescnet Carbon Dots/Clay Complexes

Carbon dots（CDs）,as an emerging luminescent nano-material with so many advantages like good optical property,biocompatibility,low toxicity and facile preparation,have been applied in many fields,such as sensing,bioimaging and lighting,etc.At present,most of the reported carbon dots will be fluorescence quenched due to the agglomeration effect in the solid state,which limits their wide application.Carbon dots are dispersed in porous or layered materials to prepare carbon dots-matrix composites.Carbon dots are dispersed by the space restriction of matrix,which can realize the carbon dots fluorescence in solid state.Nowadays,CDs in the solid state with tunable color are scarcely reported.The solid-state CDs/clay hybrid materials with multiple luminescent color are obtained by controlling the reaction condition or combining other color of luminescent materials.The specific work is as follows:1.The solid-state SNC/Lap mateirals with multiple luminescent color were prepared through an easy solvothermal method with citric acid and thiourea as the precursors.We prove that the luminescence performances of the material are closely related with the amount of COOH on the surface of carbon dots（SNC）and the extent carbonization of SNC through research and analysis.In addition,the amount of COOH on the surface of SNC and the extent carbonization of SNC can be controlled by changing the reaction condition including reaction temperature,heating time and the ratio of the reactors.Therefore,the luminescent color of SNC/Lap can be tuned by changing the reaction condition,including cyan,green,yellow-green,yellow and orange light.Additionally,SNC/Lap possesses good optical and thermal stability.Hence SNC/Lap is a good candidate in the filed of solid-state optical devices,which possesses an important application value in the field of colorful luminescent material,and it can be applied in white light emitting diodes.2.CDs nanomaterials were in situ synthesized between laponite layers by hydrothermal method with citric acid as carbon source and urea as nitrogen source.And CDs/clay composites（CDs/Lap）were prepared to realize the solid luminescence of CDs.However,the prepared CDs/Lap mainly show luminescence emission in the blue-to-green spectral region,and the SNC/Lap also lacks red luminescence,which cause that the white luminescence can not be achieved and limit their further application.Therefore,the lanthanide complexes（Eu（DPA）₃）and CDs were intercalated within the laponite to achieve red and white luminescence.The luminescent color of Eu-CDs@Lap can be tuned by varying the wavelength of the excitation light,including blue,red and white light.These good optical properties make Eu-CDs@Lap applied in the solid-state and multiple-color luminescent devices and lighting fields.