화학공학소재연구정보센터
Fuel Processing Technology, Vol.183, 8-18, 2019
Structural characterization of graphenic material prepared from anthracites of different characteristics: A comparative analysis
The purpose of this study is to evaluate the effects of minerals, elemental composition and macerals in anthracite on the microstructure and chemical composition of anthracite-based graphene. Two types of high rank B anthracite (ISO 11760 - Classification of coals) were selected as carbon sources, of which WTP is moderately high vitrinite, low-medium ash anthracite, and XFL is high vitrinite, very low ash anthracite. Natural graphite G-LT was used as a contrast. After the graphitization of raw and demineralized samples at 2800 degrees C, the anthracite based graphene was synthesized by a modified version Hummers method. The morphology-of-raw-anthracites and G-LT was observed by optical microscope. From the results obtained by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy, it was possible to evaluate the morphology and microstructure evolution of raw materials, intermediate products and graphene sheets (GS). The results showed that with or without demineralized, the two anthracites can be used for preparing anthracite-based graphene, showing a typical two-dimensional lamellar structure. The minerals inherent in anthracite were not favorable to high temperature graphitization and inhibited the ordering of GS, resulting in the existence of various inorganic elements in the prepared graphene oxides (GOs), and eventually led to multiple irregular pore defects in anthracite-based graphene. The ability of anthracites to graphitize is different, and even anthracites of close rank, such as the WTP and XFL anthracites, show distinct evolution during high temperature treatment. The higher the net hydrogen content in raw anthracite is, the more favorable graphitization is, the easier the formed anthracite-based graphite is to oxidize and intercalate, and the easier it is to reduce the O/C ratio of the final graphene product.