Abstract
Porous biomass-based chars are promising active materials for the adsorption of greenhouse gases such as carbon dioxide. In the Middle East, an exceptionally abundant biomass resource is the date palm tree, for which reason there is an increasing interest in using its fruit pits as bio-char precursors. We designed a KOH-activated carbon-carbon powder, constituted by a mixture of two components, reduced graphene oxide (rGO) and a palm date seeds (bio-)char, and investigated its performance in capturing CO
2
gas. The optimised mixture had a specific surface area of 845 m
2
/g, with 92% of the pore volume attributed to microporosity, and a CO
2
adsorption capacity (at 0 °C, 1 bar) of 3.4 mmol/g. Given the observed “sorption dampening” action of the rGO, it effectively acted as an indirect probe on how the CO
2
uptake is impacted by the presence of potassium. Here, we suggest that the alkali metal cations, intercalated at the surface graphene layers, improve the CO
2
adsorption capacity of the activated bio-char component.
Graphical abstract