Unveiling the synergistic role of N-Doping and Ca/Al decoration in C68-graphyne for efficient CO2 capture: A DFT-D2 study

Abstract

This study employs the DFT-D2 method to investigate the CO2 adsorption properties of pristine and doped/decorated C68-GY structures. By placing the CO2 molecule in various sites on these structures, we identify the most stable configurations. Additionally, we examine the impact of dopants, specifically N, Ca, and Al atoms, on CO2 adsorption. Our results reveal that decorating with Ca and Al significantly enhances the ability to adsorb and trap CO2 molecules, while N doping does not have a similar effect. Notably, the highest binding energy is observed in the N-doped C68-GY structure with a decorated Ca atom (N, Ca-C68-GY) at -3.610 eV, indicating that the simultaneous presence of N and Ca atoms can remarkably enhance CO2 adsorption ability. The adsorption energy of CO2 onto N, Ca-C68-GY in its most stable configuration is -1.551 eV, representing a significant improvement of approximately 9 times compared to pristine C68-GY. On the pristine C68-GY surface, the capacity for capturing CO2 is 31.40 wt%, which remarkably increases to 60.70 wt% on the N, Ca-C68-GY structure. Overall, these research findings provide valuable insights into designing efficient materials for CO2 capture purposes.