First-principles study of chi3-borophene for charge-modulated switchable CO2 capture
A first-principles calculation is performed to investigate the switchable CO2 capture on chi3-borophene by injecting/removing the extra electrons. The results show that the CO2 adsorption energy on the neutral chi3-borophene is 0.150 eV. After extra 2.5 e injected, the adsorption energy is raised up to 0.802 eV, showing a significant enhancement with the change from the physical adsorption to chemical adsorption. Furthermore, both the CO2 capture and release processes are exothermic reactions by injecting/removing extra electrons. chi3-borophene possesses a metallic electronic structure, which is conducive to the injection of extra electrons. The minimum charge density for CO2 capture on negatively charged chi3-borophene is 1.6×1014 e/cm2. The CO2 capture capacity of chi3-borophene is 4.09×1014 cm-2. Finally, we study the selectivity of negatively charged chi3-borophene. The results show that the negatively charged chi3-borophene possesses a high selectivity for CO2 from its mixtures with CO, CH4, NH3, N2, H2S, and H2. chi3-borophene is a new promising charge-modulated switchable CO2 capture material with good stability, high CO2 capture capacity, high selectivity, and excellent electronic conductivity.