Structural evolution and CO$_2$ capture performance of silicon oxycarbide-derived carbon by thermal-treatment under an Ar atmosphere

[摘要] In this paper, we investigated the effect of thermal-treatment under an Ar atmosphere on the structural evolution of silicon oxycarbide-derived carbons (SiOC-DCs) by adjusting the temperature from 1200 to 2100$^{\circ}$C, which will be characterized by means of N$_2$ adsorption, X-ray diffraction, Raman and transmission electron microscopy techniques, and studied their CO$_2$ capture performances. The results show that the structure of SiOC-DCs varied regularly with treatment temperature. The porosity and crystallinity of the as-received sample are almost stable when the thermal-treatment temperatureis <1500$^{\circ}$C. Subsequently, increasing the temperature (especially up to 1800$^{\circ}$C) will lead to an obvious improvement in the carbon crystallinity at the cost of pore structure breakage, which can be characterized by a quick decrease in the surface area and total pore volume of SiOC-DCs. Interestingly, the as-received SiOC-DC sample exhibits good CO$_2$ captureperformance at 0◦C under ambient pressure, up to 3.16 mmol g$^{−1}$. The thermal-treatment process under an Ar atmosphere in the range of 1200–1500$^{\circ}$C could further help in increasing the CO$_2$ adsorption ability by increasing the ultra-micropore ($d$ < 0.6 nm) volume.

[学科分类] 材料工程

[关键词] Silicon oxycarbide;carbon;thermal-treatment;porosity;crystallinity;CO$_2$ capture performance.