Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 200444, P.R. China.
SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, P.R. China.
Nat Commun. 2014 Oct 28;5:5357. doi: 10.1038/ncomms6357.
Graphene quantum dots (GQDs) have various alluring properties and potential applications, but their large-scale applications are limited by current synthetic methods that commonly produce GQDs in small amounts. Moreover, GQDs usually exhibit polycrystalline or highly defective structures and thus poor optical properties. Here we report the gram-scale synthesis of single-crystalline GQDs by a facile molecular fusion route under mild and green hydrothermal conditions. The synthesis involves the nitration of pyrene followed by hydrothermal treatment in alkaline aqueous solutions, where alkaline species play a crucial role in tuning their size, functionalization and optical properties. The single-crystalline GQDs are bestowed with excellent optical properties such as bright excitonic fluorescence, strong excitonic absorption bands extending to the visible region, large molar extinction coefficients and long-term photostability. These high-quality GQDs can find a large array of novel applications in bioimaging, biosensing, light emitting diodes, solar cells, hydrogen production, fuel cells and supercapacitors.
石墨烯量子点（GQDs）具有各种诱人的性质和潜在的应用，但由于目前的合成方法通常只能少量合成 GQDs，其大规模应用受到限制。此外，GQDs 通常表现出多晶或高度缺陷的结构，因此光学性质较差。在这里，我们报告了一种简便的分子融合方法，在温和的绿色水热条件下，以克级规模合成单晶 GQDs。该合成方法涉及芘的硝化，然后在碱性水溶液中进行水热处理，其中碱性物质在调节其尺寸、功能化和光学性质方面起着关键作用。单晶 GQDs 具有优异的光学性质，如明亮的激子荧光、延伸到可见光区域的强激子吸收带、大的摩尔消光系数和长期光稳定性。这些高质量的 GQDs 在生物成像、生物传感、发光二极管、太阳能电池、制氢、燃料电池和超级电容器等领域有着广泛的应用。
