Multicolor emissive carbon dots(M-CDs)have tremendous potential applications in manifold fields of bioimaging,biomedicine and light-emitting devices.Until now,it is still difficult to produce fluorescence tunable CDs ...Multicolor emissive carbon dots(M-CDs)have tremendous potential applications in manifold fields of bioimaging,biomedicine and light-emitting devices.Until now,it is still difficult to produce fluorescence tunable CDs with high quantum yield across the entire visible spectra.In this work,a type of M-CDs with concentration-tunable fluorescence and solvent-affected aggregation states was synthesized by solvothermal treatment of citric acid(CA)and 1-(2-pyridylazo)-2-naphthol(PAN)and the formation mechanism was monitored by different reaction time and raw material ratio.The fluorescence spectra of M-CDs in organic solvents can range from 350 to 750 nm by adjusting the concentration.M-CDs possess different aggregation states in water and organic solvents,accompanied by different fluorescence emission,which is attributed to the different surface states of various component CDs in M-CDs.Moreover,the obtained products can be uniformly dispersed into polymethylmethacrylate(PMMA)solutions as well as epoxy resins to fabricate transparent CDs/PMMA films and CDs/epoxy composites,which can effectively prevent the aggregation and produce multicolor and white light-emitting diodes(WLED).In addition,the prepared WLED with Commission Internationale de L’Eclairage(CIE)of(0.29,0.31)by using M-CDs/epoxy resin as packages,demonstrating the M-CDs exhibit potential applications for light-emitting devices.展开更多
Carbon dots(CDs),as a new kind of carbon-based luminescent nanomaterials,have drawn widespread attention in the fields of fluorescence sensing,optoelectronic devices,and biological imaging.This work uses citric acid(C...Carbon dots(CDs),as a new kind of carbon-based luminescent nanomaterials,have drawn widespread attention in the fields of fluorescence sensing,optoelectronic devices,and biological imaging.This work uses citric acid(CA)and Nile Blue A(NBA)as precursors.By simply changing the solvent in the reaction,their bandgaps were systematically controlled,thereby successfully obtaining bright blue,yellow and red fluorescence emission CDs(B-,Y-and RCDs).The higher quantum yield(QY)of B-,Y-and RCDs are 64%,57%and 51%,respectively.The selected precursors and different solvents are the key to the formation of three emission CDs.Detailed characterization and density functional theory(DFT)calculations further indicate that the difference in emission color of CDs is due to the size of the sp^(2) conjugate domain.In addition,we used multicolor CDs as fluorescent probes to investigate their performance in detection.Among them,BCDs and YCDs can detect Sudan Red I with high selectivity and sensitivity.In the concentration range of 0 to 80 pM,the detection limits are 56 and 41 nM,respectively.Multicolor emitting phosphors and fluorescent films are also obtained by mixing CDs with other matrices.Using Ultraviolet(UV)chip as the excitation source and combining with multicolor fluorescent film and a certain proportion of B-,Y-,and RCDs/epoxy resin composites,bright monochromatic light-emitting diodes(LEDs)and white LED(WLED)with high color rendering index(CRI)were prepared.The above results indicate that the multicolor CDs prepared by us have great application potential in the fields of food safety control and optical devices.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51678409,51638011 and 51578375)Tianjin Research Program of Application Foundation and Advanced Technology(Nos.18JCYBJC87500 and 15ZCZDSF00880)+1 种基金State Key Laboratory of Separation Membranes and Membrane Processes(No.Z1-201507)the Program for Innovative Research Team in University of Tianjin(No.TD13-5042).
文摘Multicolor emissive carbon dots(M-CDs)have tremendous potential applications in manifold fields of bioimaging,biomedicine and light-emitting devices.Until now,it is still difficult to produce fluorescence tunable CDs with high quantum yield across the entire visible spectra.In this work,a type of M-CDs with concentration-tunable fluorescence and solvent-affected aggregation states was synthesized by solvothermal treatment of citric acid(CA)and 1-(2-pyridylazo)-2-naphthol(PAN)and the formation mechanism was monitored by different reaction time and raw material ratio.The fluorescence spectra of M-CDs in organic solvents can range from 350 to 750 nm by adjusting the concentration.M-CDs possess different aggregation states in water and organic solvents,accompanied by different fluorescence emission,which is attributed to the different surface states of various component CDs in M-CDs.Moreover,the obtained products can be uniformly dispersed into polymethylmethacrylate(PMMA)solutions as well as epoxy resins to fabricate transparent CDs/PMMA films and CDs/epoxy composites,which can effectively prevent the aggregation and produce multicolor and white light-emitting diodes(WLED).In addition,the prepared WLED with Commission Internationale de L’Eclairage(CIE)of(0.29,0.31)by using M-CDs/epoxy resin as packages,demonstrating the M-CDs exhibit potential applications for light-emitting devices.
基金supported by the National Natural Science Foundation of China(Nos.51678409,51638011,and 51578375)Tianjin Research Program of Application Foundation and Advanced Technology(Nos.19JCYBJC19800,18JCYBJC87500,and 15ZCZDSF00880)+1 种基金State Key Laboratory of Separation Membranes and Membrane Processes(Z1-201507)the Program for Innovative Research Team in University of Tianjin(TD13-5042).
文摘Carbon dots(CDs),as a new kind of carbon-based luminescent nanomaterials,have drawn widespread attention in the fields of fluorescence sensing,optoelectronic devices,and biological imaging.This work uses citric acid(CA)and Nile Blue A(NBA)as precursors.By simply changing the solvent in the reaction,their bandgaps were systematically controlled,thereby successfully obtaining bright blue,yellow and red fluorescence emission CDs(B-,Y-and RCDs).The higher quantum yield(QY)of B-,Y-and RCDs are 64%,57%and 51%,respectively.The selected precursors and different solvents are the key to the formation of three emission CDs.Detailed characterization and density functional theory(DFT)calculations further indicate that the difference in emission color of CDs is due to the size of the sp^(2) conjugate domain.In addition,we used multicolor CDs as fluorescent probes to investigate their performance in detection.Among them,BCDs and YCDs can detect Sudan Red I with high selectivity and sensitivity.In the concentration range of 0 to 80 pM,the detection limits are 56 and 41 nM,respectively.Multicolor emitting phosphors and fluorescent films are also obtained by mixing CDs with other matrices.Using Ultraviolet(UV)chip as the excitation source and combining with multicolor fluorescent film and a certain proportion of B-,Y-,and RCDs/epoxy resin composites,bright monochromatic light-emitting diodes(LEDs)and white LED(WLED)with high color rendering index(CRI)were prepared.The above results indicate that the multicolor CDs prepared by us have great application potential in the fields of food safety control and optical devices.