Enhanced CO2 capture and separation in two-dimensional carbonaceous materials through Li metal doping and coordination environment modification

As a major greenhouse gas, CO 2 significantly contributes to environmental challenges, necessitating advanced capture and separation technologies to mitigate emissions. Herein, we systematically explore CO 2 capture and separation using a two-dimensional C 2 O framework, specifically constructing C 2 X and Li-doped C 2 X (X = O, N, CH, B) through Li doping and coordination environment modifications. The study comprehensively analyzes structural stability, pore characteristics, electronic properties, CO 2 adsorption capacity and separation performance, gas-structure interactions, and CO 2 spatial distribution patterns within both C 2 X and Li-C 2 X systems. Results demonstrate that Li-C 2 X structures exhibit significantly enhanced binding energies of − 1.75 to − 7.81 eV and cohesive energies of 5.91 to 6.77 eV/atom, attributable to the optimized coordination environment promoting strong interactions. Li–C 2 B achieves an exceptional CO 2 adsorption capacity of 12.60 mmol/g at 298 K and 1.0 bar, along with high selectivity for CO 2 over N 2 of ~ 593 and CH 4 of ~ 2109. These results are from the modified coordination environment and Li incorporation. Analyses of CO 2 spatial arrangements confirm that electropositive Li atoms, engaging in interactions with electronegative O atoms of CO 2 , facilitating vertical configurations and compact distributions. These results underscore the ultra-high-performance potential of Li-C 2 X adsorbents, where coordination environment refinement synergistically enhances CO 2 capture and separation efficacy. Strategic dual-Li doping coupled with coordination-engineered 2D carbon frameworks (C 2 X, X = O/N/CH/B) demonstrates breakthrough CO 2 capture and separation performance, where precisely tailored Li-X coordination motifs synergistically enhance adsorbent-adsorbate interactions while achieving remarkable CO 2 adsorption capacity and exceptional selectivity.