Structural evolution and \(\hbox {CO}_{2}\) capture performance of silicon oxycarbide-derived carbon by thermal-treatment under an Ar atmosphere

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 \(2100^{\circ }\hbox {C}\), which will be characterized by means of \(\hbox {N}_{2}\) adsorption, X-ray diffraction, Raman and transmission electron microscopy techniques, and studied their \(\hbox {CO}_{2}\) 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 \(<1500^{\circ }\hbox {C}\). Subsequently, increasing the temperature (especially up to \(1800^{\circ }\hbox {C}\)) 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 \(\hbox {CO}_{2}\) capture performance at \(0^{\circ }\hbox {C}\) under ambient pressure, up to \(3.16\,\hbox {mmol}\,\hbox {g}^{-1}\). The thermal-treatment process under an Ar atmosphere in the range of 1200–1500\(^{\circ }\hbox {C}\) could further help in increasing the \(\hbox {CO}_{2}\) adsorption ability by increasing the ultra-micropore (\(d < 0.6\,\hbox {nm}\)) volume.