Abstract
In this work, we demonstrate that a simple hydrothermal treatment followed by pyrolysis of regular and diet soft drinks can generate well-defined carbon structures including solid and hollow spheres with a high degree of microporosity. These materials show high and selective CO2 adsorption with a capacity up to 4.65 mmol g−1 at 0 °C and 1 bar depending on the particular soft drink used as the precursor. Isosteric heats of adsorption ranged from 22.3 kJ mol−1 to 29.2 kJ mol−1 which suggests a relatively low regeneration energy for ease of re-use. Carbon dioxide adsorption cycles were repeated for ten cycles with no loss of capacity confirming the reusability of the carbon. We also explore the effect of artificial sweeteners on the morphology and CO2 interaction of the resulting carbon materials. These results show that waste soft drinks can be used to create high-value, porous carbon materials for applications such as carbon capture.
