掺氮荧光碳量子点的制备及性能研究

Preparation and properties of nitrogen-doped fluorescent carbon quantum dots

以柠檬酸为碳源、对氨基苯甲酸为氮源,通过一步水热法制备了氮掺杂荧光碳量子点(N-CQDs),采用透射电子显微镜、傅里叶变换红外光谱仪、稳态瞬态荧光磷光光谱仪对其形貌、结构和光谱进行表征,研究了反应温度、反应时间、酸碱度对N-CQDs荧光性能的影响。结果表明:N-CQDs呈球形,具有良好的分散性;N-CQDs的荧光强度较碳量子点增强约17倍,N-CQDs最佳激发波长为404nm,最佳发射波长为480nm,说明氮的掺杂有助于碳量子点荧光强度的增强;反应温度为180℃、反应时间为6h,酸碱度为中性时,N-CQDs荧光强度最强。

Nitrogen-doped fluorescent carbon quantum dots(N-CQDs)were prepared by one-step hydrothermal method using citric acid as carbon source and p-aminobenzoic acid as nitrogen source.The morphology,structure and spectra of N-CQDs were characterized by transmission electron microscopy,Fourier transform infrared spectrometer and steady-state transient fluorescence phosphorescence spectrometer.The effects of reaction temperature,reaction time and pH on the fluorescence properties of N-CQDs were studied.The results showed that N-CQDs were spherical and exhibited good dispersion.The fluorescence intensity of N-CQDs was about 17 times stronger than that of carbon quantum dots.The optimal excitation wavelength of N-CQDs was 404nm,and the optimal emission wavelength was 480nm,indicating that nitrogen doping contributed to the enhancement of fluorescence intensity of carbon quantum dots.The fluorescence intensity of N-CQDs was strongest when reaction temperature was 180℃,reaction time was 6h and pH was neutral.