The properties of Balsa wood carbon quantum dots and its application in fluorescent ink
Carbon quantum dots(CQDs)are fluorescent nanomaterials with a size less than 10 nm and their preparation methods are diverse.Due to excellent luminescent properties,carbon quantum dots have attracted much attention in multiple fields,especially in the field of anti-counterfeiting.To explore the similarities and differences in the fluores-cence properties of carbon quantum dots prepared by different methods,this study used Balsa wood packaging waste with light weight,non-toxic properties,and its own silicon element as raw materials.The silicon element contained in Balsa wood was used as a doping element in the synthesis process of CQDs to improve the fluorescence quantum yield of CQDs.CQDs were prepared using the one-step hydrothermal method and microwave method,which were named as H-CQDs and M-CQDs,respectively.The optimal preparation process parameters for the hydrothermal method were the solid-liquid ratio of 1∶120,reaction temperature of 190 ℃,and reaction time of 10 h.While the optimal process parameters for the microwave method were the solid-liquid ratio of 1∶60,reaction power of 720 W,and reaction time of nine minutes.H-CQDs and M-CQDs were selected under the optimal experimental conditions for examinations of transmission electron microscopy(TEM),ultraviolet(UV),Fourier transform infrared(FT-IR),fluorescence and other tests to analyze and compare the similarities and differences of their performances.Through the analysis of the physical morphology,composition,and fluorescence performance of the prepared carbon quantum dots,it was found that both methods can emit blue fluorescence under the 365 nm ultraviolet light irradiation,but the fluorescence inten-sity of H-CQDs can reach up to three times of M-CQDs.The optimal excitation wavelength for H-CQDs was 340 nm,while the optimal excitation wavelength for M-CQDs was 360 nm.Meanwhile,CQDs solution was freeze-dried into powder,then the elements and functional groups in it were detected.According to the FT-IR and XPS results,it can be concluded that the optical properties of H-CQDs and M-CQDs were similar with the same luminescence color and similar peak positions.However,there were also certain differences in excitation wavelengths.The number of oxygen-containing functional groups in H-CQDs was significantly higher than that in M-CQDs.The fluorescence quantum yield of H-CQDs(2.82％)was higher than that of M-CQDs(1.61％),the average particle size of H-CQDs was 4.52 nm,while the average particle size of M-CQDs was 6.08 nm,and their optical properties were more excellent.At the same time,H-CQDs were used to prepare fluorescent ink,which showed obvious blue fluorescence under UV light.This finding indicates that Basha wood carbon quantum dots can successfully prepare fluorescent ink,providing a pos-sible approach for its application in anti-counterfeiting.
万方数据
维普
