Fig. 1: CO₂ adsorption in 3 nm CH slit pore with different water contents under 10 bars.

a Total CO₂ amount in the entire channel. b Dissolved CO₂ amount in the interfacial water film. c Gaseous CO₂ amount in the CH channel. The adsorption amount is taken from the average of the last 2 ns adsorption at the equilibrium stages. The value 8.6 nm⁻² is the coverage density of one water monolayer on the CH surface. Error bars are from the standard deviation resulting from the last 1 ns simulation of CO₂ adsorption. The unit is the number of molecules. d, e Molecular simulation snapshots showing CO₂ adsorption into the CH channels with one and four water layers, respectively. f Water density distribution along the Z direction of the CH channel at different water coverage densities. g Diffusion coefficients of CO₂ in the CH channel with different thicknesses of water coverage. Blue dashed lines stand for the diffusion coefficients of the surface-trapped CO₂ and free CO₂ in the dry CH nanopore. Red dashed lines designate the attractive potential between CO₂ and CH surface (E_att) and the adsorption energy of CO₂ (E_ads) as a function of the water coverage density. h The CO₂ isosteric heat of adsorption (Q_st) in 3 nm CH slit pores under varying water content. Source data are provided as a Source Data file.