Study on the Formation Mechanism of a Core-Shell Structure during Graphitization of Anthracite.

Graphite is a revolutionary material, and the development of synthetic graphite could potentially solve the shortage of natural graphite in the future. In this paper, the formation of core-shell-structured synthetic graphite prepared from an anthracite-FeO mixture was systematically investigated by a two-step method. First, heat treatment was performed on a layer of almandine (3FeO·Al2O3·3SiO2) particles to obtain a large quantity of uniform-sized glass-phase spheroids. Second, the deashed anthracite was graphitized on the surface of the obtained spheroids to prepare core-shell-structured graphite. Furthermore, the obtained graphite products were systematically characterized by XRD, Raman spectroscopy, SEM-EDS, and TEM. Finally, a model was proposed to illustrate the formation mechanism of the core-shell structure during graphitization of the anthracite-almandine mixture. Under lower temperatures, almandine started to melt into spheroids. Under higher temperatures, the volatile components in the anthracite turned into the gas phase, and the carbon matrix started to bend on the surface of the core material and deposit layer by layer, thus forming the core-shell-structured graphite. The findings could provide theoretical guidance for the synthetic graphite industry and have meaningful implications for the coal chemistry field.

Complete chloroplast genome of Erythropsis kwangsiensis (Sterculiaceae), an endemic wild tree from South China.

Erythropsis kwangsiensis (Sterculiaceae), a wild endangered tree that grows in South China, is an economically important species. There is scant information available on the chloroplast (cp) genome of this species. The present study is the first to analyze the cp genome of E. kwangsiensis using genome skimming. The whole cp genome is 160,836 bp long with 131 genes, including 84 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. The GC content is 37.0%. Phylogenetic analysis revealed a close relationship to Firmiana colorata. This data will be useful for future investigations of conservation genetics and potential applications in breeding new varieties of this endangered and economically important tree.