含氮石墨烯量子点的制备及其光学性质研究  

Preparation and Optical Properties of Graphene Quantum Dots Containing Nitrogen

作　　者：张东梅[1] 田磊[1] 郭慧林[1] ZHANG Dong-Mei TIAN Lei GUO Hui-Lin(Key Laboratory of Synthetic and Natural Functional Molecule Chemistry （Ministry of Education）, College of Chemistry and Materials Science, Northwest University, Xi＇an 710069, China)

机构地区：[1]西北大学化学与材料科学学院,合成与天然功能分子化学教育部重点实验室,西安710069

出　　处：《无机材料学报》2016年第10期1123-1128,共6页Journal of Inorganic Materials

基　　金：陕西省自然科学基金(2014JM2042);陕西省教育厅专项基金(14JK1728)~~

摘　　要：采用水热法一步合成了含氮石墨烯量子点(NGQDs),通过原子力显微镜(AFM)、透射电镜(TEM)、X射线光电子能谱(XPS)等对NGQDs的形貌和组成进行表征,并进一步通过紫外–可见光谱(UV-Vis)、荧光光谱(PL)等手段研究了NGQDs的光学性质。AFM和TEM分析结果表明,NGQDs尺寸约为8.9 nm、厚度为0.6~2.0 nm(即1~3个碳原子层)。XPS分析结果表明NGQDs中氮含量约为17%,且氮元素主要以"吡咯N"形式存在。光谱学实验表明,NGQDs的激发光谱与吸收光谱基本一致,且其发射光谱与激发波长之间不存在依赖关系。此外,NGQDs的量子产率为~18%,并随着含氮量的增加而增加,且其荧光寿命衰变曲线可以被拟合成很好的双指数衰变曲线(τ_1=2.93 ns,τ_2=9.00 ns),表明NGQDs有两种发色源,即边缘富有含氧官能团的sp^2碳簇和含氮五元环–吡咯环。Graphene quantum dots containing nitrogen （NGQDs） were synthesized by the hydrothermal method. AFM, TEM and XPS were employed to investigate the morphology and composition of NGQDs, and their optical properties were studied by UV-Vis and photoluminescent （PL） spectroscopy. AFM and TEM images showed that NGQDs were about 8.9 nm in size and 0.6-2.0 nm in thickness （1-3 layers graphene）. The result of XPS showed that nitrogen content in NGQDs was -17% and nitrogen existed mainly in the form of ＂pyrrolic N＂. Spectroscopy experiments indicated that excitation spectra of NGQDs were similar to their absorption spectra, and their emission spectra were excitation-independent. In addition, quantum yield of NGQDs was calculated to be -18%, increasing with the content of nitrogen in NGQDs increase. Furthermore, the lifetime decay curve was well fitted to a double exponential decay curve （τt=2.93 ns, τ2=9.00 ns）, which indicates that there are two feature chromophores in NGQDs. The chromophores are sp： clusters with oxygen groups and pyrrolic ring.

关 键 词：石墨烯量子点 水热法 氮掺杂 光学性质 

分 类 号：TQ174[化学工程—陶瓷工业]