Synergetic effects of metals in graphyne 2D carbon structure for high promotion of CO2 capturing

Structural and electronic properties of co-decorated graphyne (GY) by Sc and Cr atoms toward CO2 capture are investigated by DFT-D3 method. First, different configurations of Sc-Cr co-decorated GY (SCGY) are considered to find the best site and side of GY for SC and Cr atoms and structural, magnetic, and electronic properties of them are investigated. Then, the adsorption behavior of the best configurations toward CO2 capture is followed. Results show that in single Sc or Cr decorated GY, the best site for metals is the center of the 12-membered ring (H1) and E-ads are -4.856 and -2.414 eV, respectively. In SCGY, the best site for Cr and Sc are H1 and H3 sites, but they lie in the opposite sides and E-ads improves about 0.505 eV. In brief, E-das of CO2 for pristine GY (PGY), ScGY, Cr-GY, Sc-Cr-GY, Sc-Sc-GY, and Cr-Cr-GY are about -0.242, -0.717, -1.502, -0.795, -2.970 and - 1.754 eV, respectively. Increasing of Eads due to the insertion of one or two metal atoms for some systems is about 3 to 12 times more than PGY, surprisingly. The best system can capture up to 19 CO2 molecules with of - 0.516 eV/CO2 that is CO2 storage capacity of 55.66 wt%. These results show that co-decorated GYs with various metals, due to having synergistic effects, can be used as promising candidates for the CO2 capture, storage, detection, and removal applications in the future.