Kurosu Shunji, Kaizuka Yuma, Zhou Kang, Yokota Haruki, Hashimoto Ryusuké, Yanagisawa Keiichi, Shimoshigé Hirokazu, Tanuma Yuri, Morimoto Hisao, Maekawa Toru
Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Japan.
Graduate School of Interdisciplinary New Science, Toyo University, 2100, Kujirai, Kawagoe, Japan.
Commun Chem. 2024 Nov 30;7(1):283. doi: 10.1038/s42004-024-01367-0.
Carbon quantum dots (CQDs) have recently received a lot of attention due to their unique physical properties, and their environmentally friendly features such as low toxicity and high biocompatibility. Supercritical fluids, which possess unusual properties such as high solubility, high diffusivity, low viscosity and zero surface tension, are now commonly used particularly in the fields of electronic, chemical and materials science and engineering. Here, we synthesise carbon nano/microparticles in supercritical acetone, in which neither external molecules nor starting materials are dissolved/dispersed. We find that carbon microparticles and nano structures such as graphene quantum dots (GQDs), carbon nano onions (CNOs) and elongated carbon nano onions (eCNOs) are self-assembled via thermal decomposition of acetone under its supercritical conditions. We also find that the carbon microparticles are in fact formed by GQDs, CNOs and eCNOs, the microparticles being physically resolved into GQDs, CNOs and eCNOs with sonication. The fluorescence features of the carbon nano structures are clarified, noting that no photobleaching was observed for at least one month. The present result may well lead to the development of facile bottom-up methodologies for synthesising nano materials in solvents under their supercritical conditions without using any external precursors/starting materials.
碳量子点（CQDs）因其独特的物理性质以及低毒性和高生物相容性等环境友好特性，近来备受关注。超临界流体具有诸如高溶解性、高扩散性、低粘度和零表面张力等特殊性质，如今尤其常用于电子、化学以及材料科学与工程领域。在此，我们在超临界丙酮中合成碳纳米/微粒，在该体系中既没有外部分子也没有起始原料被溶解/分散。我们发现碳微粒以及诸如石墨烯量子点（GQDs）、碳纳米洋葱（CNOs）和拉长的碳纳米洋葱（eCNOs）等纳米结构是通过丙酮在其超临界条件下的热分解自组装而成。我们还发现碳微粒实际上是由GQDs、CNOs和eCNOs构成，通过超声处理可将这些微粒物理分解为GQDs、CNOs和eCNOs。阐明了碳纳米结构的荧光特性，注意到至少一个月内未观察到光漂白现象。目前的结果很可能会推动在超临界条件下的溶剂中不使用任何外部前驱体/起始原料来合成纳米材料的简便自下而上方法的发展。
