Exploration and structural characteristics of laser-induced preparation of coal-based graphene

In order to explore the possibility of using laser induced technology to produce coal-based graphene by using coal as carbon-containing precursor, this paper chooses high volatile bituminous coal in Wajinwan and low volatile bituminous coal in Tashan as carbon sources, and uses laser induced technology to produce coal-based graphene. Raman spectroscopy (Raman), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) were used to characterize raw coal and the products after laser irradiation. The results show that after laser irradiation, the Raman spectra of the products have a typical 2D peaks and sharp G peaks, indicating an alignment structure for the products generated. XRD results show that the diffraction peaks (002) and (100) become narrow and sharp, and the layer spacing is 0.345 nm. XPS results show that the C=C bond and π—π interaction of sp² are enhanced after laser irradiation of bituminous coal, forming sp² network aromatic layer. The layered porous structure of the sample after laser irradiation was observed by SEM, HRTEM results show that the aromatic fringe has the characteristics of few graphene layers, the graphene layers are mostly concentrated in 2−10 layers, and the layer spacing is 0.346 nm, which is basically consistent with the XRD results. All these data indicate that bituminous coal has been formed into coal-base graphene after laser irradiation. However, limited by the number of samples used in this paper, this study is only a preliminary understanding, and further research needs to increase the number of samples.