蘼芜水热合成碳量子点的透射电子显微镜结构表征  

Characterization of Hydrothermally Synthesized Carbon Quantum Dots from Ligusticum Wallichii by Transmission Electron Microscopy

作　　者：孙晶莹 郭琳娜 董鑫[1] 黄烘[1] 梁超伦[1] SUN Jingying;GUO Linna;DONG Xin;HUANG Hong;LIANG Chaolun(Instrumental Analysis and Research Center,Sun Yat-sen University,Guangzhou 510275,China)

机构地区：[1]中山大学分析测试中心,广东广州510275

出　　处：《分析测试技术与仪器》2024年第3期161-165,共5页Analysis and Testing Technology and Instruments

摘　　要：运用透射电子显微镜技术(transmission electron microscopy,TEM)观察分析了以植物蘼芜为碳源,通过水热法合成的CQDs(carbon quantum dots,CQDs)的结构.针对TEM明场像中CQDs衬度弱而难以观察的问题,利用高角环形暗场扫描透射技术(high angle annular dark field-scanning transmission electron microscopy,HAADF-STEM)在铜网中快速定位CQDs.相应区域的明场像显示CQDs形貌为不规则多边形,尺寸约3 nm.通过高分辨透射电子显微镜技术(HRTEM)及相应的快速傅里叶变换(fast Fourier transform,FFT),观察到具有六次对称性的晶格条纹(0.21 nm)和衍射斑点,以及石墨π键的层间距(0.34 nm),讨论了CQDs特征晶面指数的指标化方法.晶格结构分析结果表明,CQDs为晶态六方相类石墨烯结构.The structure of carbon quantum dots(CQDs)synthesized by one-pot hydrothermal method using Ligusticum wallichii as carbon source was observed and analyzed by the transmission electron microscopy(TEM).Aiming at the problem of weak contrast of CQDs in TEM bright field imaging,the high angle annular dark field-scanning transmission electron microscopy(HAADF-STEM)was carried out to rapidly locate the CQDs in the copper grid.The corresponding TEM images showed that the CQDs were irregular shape with a size of about 3 nm.By the high-resolution transmission electron microscopy(HRTEM)and the corresponding fast Fourier transform(FFT),the lattice fringe of 0.21 nm,diffraction with six-fold symmetry,as well as the graphitic layer spacing of 0.34 nm were observed.The indexing method of characteristic indices of crystalline CQDs was also discussed.The HRTEM analysis indicated that the CQDs were crystalline hexagonal phase graphene-like structure.

关 键 词：植物碳源 碳量子点 高分辨透射电子显微镜 

分 类 号：O656.4[理学—分析化学] TN16[理学—化学]