Yuan Jian-Min, Zhao Rui, Wu Zhen-Jun, Li Wei, Yang Xin-Guo
College of Material Science and Engineering, Hunan University, No. 2, South of Lushan Road, Changsha, 410082, China.
College of Chemistry and Chemical Engineering, Hunan University, No. 2, South of Lushan Road, Changsha, 410082, China.
Small. 2018 May;14(20):e1703714. doi: 10.1002/smll.201703714. Epub 2018 Apr 17.
Graphene oxide quantum dots (GOQDs) attract great attention for their unique properties and promising application potential. The difficulty in the formation of a confined structure, and the numerous and diverse oxygen-containing functional groups results in a low emission yield to GOQDs. Here, GOQDs with a size of about 5 nm, exfoliated from carbon fibers by microwave irradiation, are detected and analyzed. The exfoliated GOQDs are deeply oxidized and induce large numbers of epoxy groups and ether bonds, but only a small amount of carbonyl groups and hydroxyl groups. The subdomains of sp clusters, involving epoxy groups and ether bonds, are responsible for the two strong photoluminescence emissions of GOQDs under different excitation wavelengths. Moreover, GOQDs tend to self-assemble at the edges of their planes to form self-assembly films (SAFs) with the evaporation of water. SAFs can further assemble into different 3D patterns with unique microstructures such as sponge bulk, sponge ball, microsheet, sisal, and schistose coral, which are what applications such as supercapacitors, cells, catalysts, and electrochemical sensors need. This method for preparation of GOQDs is easy, quick, and environmentally friendly, and this work may open up new research interests about GOQDs.
氧化石墨烯量子点（GOQDs）因其独特的性质和广阔的应用潜力而备受关注。受限结构形成的困难以及大量多样的含氧官能团导致GOQDs的发射产率较低。在此，检测并分析了通过微波辐照从碳纤维上剥离的尺寸约为5 nm的GOQDs。剥离的GOQDs被深度氧化，诱导产生大量环氧基团和醚键，但只有少量羰基和羟基。涉及环氧基团和醚键的sp簇亚域是GOQDs在不同激发波长下产生两种强荧光发射的原因。此外，随着水的蒸发，GOQDs倾向于在其平面边缘自组装形成自组装膜（SAFs）。SAFs可以进一步组装成具有独特微观结构的不同三维图案，如海绵块、海绵球、微片、剑麻和片状珊瑚，这些是超级电容器、电池、催化剂和电化学传感器等应用所需要的。这种制备GOQDs的方法简便、快速且环保，这项工作可能会开辟关于GOQDs的新研究方向。
