Structural evolution and CO 2 capture performance of silicon oxycarbide-derived carbon by thermal-treatment under an Ar atmosphere

Abstract

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 ∘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 temperature is < 1500 ∘C. Subsequently, increasing the temperature (especially up to 1800 ∘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 capture performance at 0 ∘C under ambient pressure, up to 3.16mmolg-1. The thermal-treatment process under an Ar atmosphere in the range of 1200–1500∘C could further help in increasing the CO 2 adsorption ability by increasing the ultra-micropore (d<0.6nm) volume.