宁夏碱沟山脱灰无烟煤石墨烯量子点制备与谱学特征
Preparation and spectroscopic characteristics of coal⁃based graphene quantum dots from demineralized anthracite in Jiangoushan，Ningxia
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摘要: 采用一步化学氧化法，以宁夏碱沟山无烟煤为碳源，探讨了脱灰无烟煤制备石墨烯量子点 的可行性。 利用 X 射线衍射分析、拉曼光谱、高分辨透射电镜、X 射线光电子能谱和荧光光谱等谱 学方法，表征了脱灰无烟煤以及产物石墨烯量子点的化学结构和化学组成。 宁夏碱沟山无烟煤及 其脱灰样品的碳质量分数较高，分别为 94.19%和 94.43%，H / C 原子比非常低，分别为 0.14 和 0.15。 原煤的显微组分以镜质体为主，为 81.4%。 X 射线衍射分析结果表明，脱灰无烟煤的芳香片层直 径(La)、堆砌高度(Lc)及平均堆积层数(Nave)均较好，La达 6.0 nm 以上，Lc为 2.02 nm，平均 Nave超 过 6，具有较高的芳香度，fa 为 0.89。 拉曼光谱分析显示，脱灰无烟煤多环芳香化合物的 C—C 震动 强烈，ID / IG 强度比为 0.85，G-D 峰位差为 157.88 cm-1 ，利于石墨烯量子点的制备。 研究发现，碱沟 山无烟煤通过一步化学氧化法可以制备出尺寸均一、晶型良好、荧光性质稳定的石墨烯量子点，芳 香簇尺寸整体较大(8~9 nm)，最大直径为 12 nm，尺寸在 6~10 nm 的芳香簇数量达 92%;与前驱体 煤样相比，脱矿煤样制备的煤基石墨烯量子点具有更小的缺陷度，ID / IG 强度比为 0.81，G-D 峰位差 为 264.25 cm-1 。 高分辨透射电镜下煤基石墨烯量子点芳香环排列比较规则，六边形晶体结构可 见，具有较好的结晶度。 X 射线光电子能谱表征表明脱灰无烟煤和所制备的石墨烯量子点的含氧 官能团较为单一，主要为 C 唐跃刚，李瑞青，樊江涛，等.宁夏碱沟山脱灰无烟煤石墨烯量子点制备与谱学特征J.煤炭学报，2022，47(12):4278-4289.Abstract: The feasibility of preparing graphene quantum dots(GQDs)from demineralized anthracite was studied by one⁃step chemical oxidation using the Jiaogoushan anthracite in Ningxia as carbon source. The chemical structure and composition of demineralized anthracite and graphene quantum dots were characterized by X⁃ray diffraction， Raman spectroscopy，high⁃resolution transmission electron microscopy，X⁃ray photoelectron spectroscopy and fluores⁃ cence spectroscopy. The carbon content of the Jiangoushan anthracite and its demineralized samples is high，94.19% and 94.43% respectively，and the H / C atomic ratio is very low，0.14 and 0.15 respectively. The macerals of raw coal are mainly vitrinite，accounting for 81.4%. The results of X⁃ray diffraction analysis show that the aromatic layer diame⁃ ter(La)，stacking height(Lc)and average stacking layer number(Nave)of demineralized anthracite are all good，with La being more than 6.0 nm，Lc being 2.02 nm，Nave being more than 6 and fa being 0.89. The Raman spectroscopy analysis shows that the C—C vibration of the demineralized anthracite polycyclic aromatic compounds is strong，the ID / IG value is 0.85，and the G—D value is 157.88 cm-1，which is conducive to the preparation of graphene quantum dots. It is found that the graphene quantum dots with uniform size，good crystal form and stable fluorescence properties can be prepared by one⁃step chemical oxidation from the Jiangoushan anthracite. The overall size of aromatic clusters of GQDs is large(8-9 nm)，the maximum diameter is 12 nm，and the number of aromatic clusters with sizes between 6-10 nm reaches 92%. Compared with precursor coal samples，the graphene quantum dots prepared from the demineralized coal samples have smaller defects，with ID / IG values of 0.81 and G-D values of 264.25 cm-1. Under the high⁃resolu⁃ tion transmission electron microscope， the aromatic rings of coal⁃based graphene quantum dots are arranged regularly，the hexagonal crystal structure is visible，and the crystallinity is good. The X⁃ray photoelectron spectroscopy shows that the oxygen containing functional groups of the demineralized anthracite and graphene quantum dots prepared are relatively simple，mainly C
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