Investigation the nature of CO2 binding to borophene χ3

Global warming following the release of greenhouse gases, especially CO2, is one of the important areas of research to adsorption of CO2 to remove it from the environment. But the CO2 binding to the surfaces is weak, and scientists want to correct this defect.
Here we used borophene χ3 as a novel 2D material with the hole density (η=1/4) and investigated the nature of CO2binding to its surface. DFT calculations and plane-wave basis set with the ultrasoft pseudopotentials were used in the quantum espresso. The GGA approximation with PBE functional was applied for the electron exchange-correlation energy. The VDW interactions were taken into account using the DFT-D2 method. The binding site for CO2 was determined and the adsorption energy and electronic properties of the χ3-CO2were analyzed.
The calculated binding energy (~0.2eV) and distance of CO2 to the surface (~3.5Å) indicated weak adsorption. The charge density differences calculation shows the charge depletion between the boron sheet and CO2. The Bader charges analysis shows that the CO2 tends to capture electrons from boron atoms. during the adsorption. Therefore, because of the electron deficiency of the surface, the CO2 physisorbed. Therefore, to achieve stronger adsorption, the surface modifications were needed.