Design and performance characterization of highly wettable core-shell structured SiC@C composites

Abstract

SiC@C composites are extensively used in high-temperature metallurgy owing to their distinctive physicochemical properties. In this study, SiC@C composites with a core-shell structure were synthesized using silicon powder and Fe2O3 as the silicon source and catalyst, respectively. The effect of various temperatures on the synthesis of the SiC@C composites was investigated. The results indicated that a SiC whiskers layer covers the graphite surface at 1600 °C. At this temperature, the production of silicon carbide reaches 9.2 %. Transmission electron microscope (TEM) revealed that the preferred growth orientation of SiC was the (111) crystal plane. Based on density functional theory, the adsorption properties of different crystal planes of SiC crystals and their interactions with Fe atoms on the crystal surface were investigated. The results showed that the adsorption properties of different SiC crystal planes varied, with the (111) crystal plane exhibiting the strongest adsorption ability. In the presence of Fe atoms, the adsorption properties of the (111) crystal plane reaches to a value of −2686.5253 Ha, indicating that Fe atoms can promote the adsorption of other atoms or molecules on the surface of SiC crystals. Additionally, the wettability of the SiC@C composites was improved, as evidenced by the decrease in the contact angle from 109° to 46°.