Effects of Coal Rank and Macerals on the Structure Characteristics of Coal‐Based Graphene Materials from Anthracite in Qinshui Coalfield

Abstract

Thirteen raw coal samples from Qinshui coalfield were prepared to produce coal‐based graphene, and the raw coal, coal‐based graphite, and coal‐based graphene sheets (GS) were characterized by X‐ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy with energy dispersive spectrometer (SEM‐EDS), and high‐resolution transmission electron microscopy (HRTEM). The results show that the graphitization degree of coal‐based graphite is positively linearly correlated with the reflectance of raw coal, has a low positive correlation with the content of inertinite, and has a low positive correlation with the content of vitrinite in raw coal. The crystallite width (La) and crystallite height (Lc) of coal‐based graphite and graphene are positively linearly correlated with the reflectance of raw coal. La and Lc of coal‐based graphite are distributed in 17.591– 48.374 nm and 11.359–23.023 nm, respectively. After redox, La and Lc of coal‐based graphene are distributed in 4.405 nm–6.243 nm and 0.804–1.144 nm, respectively. The defect degree (ID/IG) of coal-based graphene is higher than that of raw coal, demineralized coal, and coal‐based graphite. The coal‐based graphene is thin and transparent, and only contained carbon and oxygen. Combined with the parameters of XRD and HRTEM, it is calculated that the interlayer spacing (d002) of Qinshui‐coal‐based graphene is about 0.4007 nm and the number of layers (Nave) is about 5.