Physical/Materials Chemistry Division, National Chemical Laboratory, Homi Bhabha Road, Pune-411008, India.
Chemistry. 2012 Sep 24;18(39):12522-8. doi: 10.1002/chem.201201043. Epub 2012 Aug 14.
Green luminescent, graphene quantum dots (GQDs) with a uniform size of 3, 5, and 8.2(±0.3) nm in diameter were prepared electrochemically from MWCNTs in propylene carbonate by using LiClO(4) at 90 °C, whereas similar particles of 23(±2) nm were obtained at 30 °C under identical conditions. Both these sets of GQDs displayed a remarkable quantum efficiency of 6.3 and 5.1%, respectively. This method offers a novel strategy to synthesise size-tunable GQDs as evidenced by multiple characterisation techniques like transmission and scanning electron microscopy, atomic force microscopy, Raman spectroscopy and X-ray diffraction (XRD). Photoluminescence of these GQDs can be tailored by size variation through a systematic change in key process parameters, like diameter of carbon nanotube, electric field, concentration of supporting electrolyte and temperature. GQDs are promising candidates for a variety of applications, such as biomarkers, nanoelectronic devices and chemosensors due to their unique features, like high photostability, biocompatibility, nontoxicity and tunable solubility in water.
绿色发光，石墨烯量子点（GQDs）的均匀尺寸为 3、5 和 8.2（±0.3）nm 的直径电化学从 MWCNTs 在碳酸丙烯酯中使用 LiClO(4)在 90 °C，而类似的颗粒 23（±2）nm 是在 30 °C 下获得相同的条件。这两组 GQDs 分别显示出显著的量子效率为 6.3 和 5.1%。这种方法提供了一种新的策略来合成尺寸可调的 GQDs，这一点可以通过多种表征技术来证明，如透射电子显微镜、扫描电子显微镜、原子力显微镜、拉曼光谱和 X 射线衍射（XRD）。通过系统地改变关键工艺参数，如碳纳米管的直径、电场、支持电解质的浓度和温度，可以通过尺寸变化来调整这些 GQDs 的光致发光。由于其独特的特性，如高光稳定性、生物相容性、无毒和在水中可调的溶解度，GQDs 是各种应用的有前途的候选者，如生物标志物、纳米电子器件和化学传感器。
