Photoluminescent Carbon Nanoparticles:Synthesis And Investigation Of Luminescence Mechanism

A series of carbon nanoparticles were synthesized by the hydrothermal method. Synthesis conditions such as temperature, time and different molecular prescursors were investigated. Together with fluorescence properties, surface functional groups and morphology of carbon nanoparticles were discussed under these conditions. The photoluminescence of carbon nanoparticles were much enhanced with the addition of Al(NO3)3 for surface passivation; Carbon nanoparticles were entrapped into the silica-based ionogels by physical immersion, which hold a promising potential for the application of carbon nanoparticles in optoelectronic devices.(1) Optimum synthesis conditions were explored with glucose and critic acid as molecular precursors respectively. It was found that the resulted carbon dots have appropriate spherical morphology, uniform size, good dispersion, high photostability and can exhibit excitation-dependent photoluminescence behavior. The two kinds of carbon nanoparticels can emit green and blue photoluminescence under UV excitation,and the brightness of canrbon nanoparticels with critic acid as molecular precursors were much higher than that of the glucose.(2) The morphology, fluorescence properties, surface functional groups and the luminescence mechanism of carbon nanoparticels were investigated when the carbon nanoparticels reacted with Al(NO3)3, where Al(NO3)3 acts as a surface modifier at first time. It was found that the particle size, fluorescence intensity and fluorescence quantum yields of carbon nanoparticles were much enhanced with the addition of Al(NO3)3. The enhanced photoluminescence were attributed to the surface passivation.(3) Silica-based ionogels were prepared by a sol–gel route. Ionic liquids in the ionogels were extracted with acetonitrile and nanosized pores were obtained. Carbon nanoparticles were then entrapped into the ionogels by physical immersion. The Ionogels-Functionalized carbon nanoparticles Monolith emit blue photoluminescence under UV excitation. Carbon nanoparticles were confined in the nanosized pores among ionogels, leading a certain distance between the carbon nanoparticles as well as preventing them from aggregation, which contributed to the high photoluminescence. Ionogels-Functionalized carbon nanoparticles Monolith provide a new potentiality for the applications of carbon nanoparticles in optoelectronic devices.