Li Ruiqing, Tang Yuegang, Che Qili, Huan Xuan, Ma Pengliang, Luo Peng, Mao Xingjun
College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), D11, Xueyuan Road, Beijing 100083, People's Republic of China.
Geological Bureau of Ningxia Hui Autonomous Region, 158 Xinchang East Road, Jinfeng District, Yinchuan 750004, People's Republic of China.
Nanotechnology. 2022 Aug 17;33(45). doi: 10.1088/1361-6528/ac842e.
Coal-based graphene sheets (GS) and coal-based graphene quantum dots (GQDs) are usually prepared separately. In this paper, symbiosis of coal-based GS and coal-based GQDs was successfully prepared with our proposed preparation method by using three raw coals with different reflectance (collected from Qinshui coalfield, Shanxi Province) as carbon sources. The results showed that coal-based GS and coal-based GQDs can exist stably in the symbiosis and are distributed in different layers, and the GQDs are freely distributed between layers of GS. The average number of GS () in the three symbiosis is about 7 and the average interlayer spacing () is about 0.3887 nm. The average diameter of GQDs in the three symbiosis is about 4.255 nm and the averageis about 0.230 nm. The averageof the three symbiosis was about 3 and the averageis about 0.361 nm. The morphology and crystal parameters of symbiosis is more similar to that of graphene, the elements are only carbon and oxygen. In the prepared symbiosis, the higher the reflectance of raw coal, the smoother the lattice skeleton and the less vortex-layer structure of GS, and the larger the diameter and the denser the six membered ring of GQDs. The C and O functional groups of the prepared symbionts are similar. The higher the reflectance of coal, the higher the content of C-C/C=C. Under ultraviolet light, the prepared products all emit blue, and the higher the reflectance of coal, the higher the ultraviolet absorption, and the stronger the fluorescence intensity.
煤基石墨烯片（GS）和煤基石墨烯量子点（GQDs）通常是分别制备的。本文以三种不同反射率的原煤（取自山西省沁水煤田）为碳源，采用我们提出的制备方法成功制备了煤基GS和煤基GQDs的共生体。结果表明，煤基GS和煤基GQDs能在共生体中稳定存在且分布于不同层，GQDs自由分布于GS层间。三种共生体中GS的平均层数（）约为7，平均层间距（）约为0.3887nm。三种共生体中GQDs的平均直径约为4.255nm，平均（此处原文似乎不完整）约为0.230nm。三种共生体的平均（此处原文似乎不完整）约为3，平均（此处原文似乎不完整）约为0.361nm。共生体的形态和晶体参数与石墨烯更相似，元素仅为碳和氧。在所制备的共生体中，原煤反射率越高，GS的晶格骨架越光滑，涡层结构越少，GQDs的直径越大且六元环越密集。所制备共生体的C和O官能团相似。煤的反射率越高，C-C/C=C的含量越高。在紫外光下，所制备的产物均发出蓝色光，煤的反射率越高，紫外吸收越高，荧光强度越强。
