Theoretical Investigation of Br2 and Cl2 Detection by the Pristine and Co-Doped Graphyne

The Br 2 and Cl 2 interaction with the intrinsic, and Co-doped graphyne nanosheets has been explored by density functional theory calculations. Two vertical and parallel configurations were identified for Br 2 and Cl 2 adsorption. Calculations showed that the adsorption of Br 2 was stronger than Cl 2 on the graphyne nanosheet. Neither Br 2 nor Cl 2 could make serious changes to the HOMO-LUMO gap (E g ) and electrical resistance pf pristine sheet. By manipulating the structure of pristine graphyne by Co atom, its reactivity and sensitivity dramatically improved toward Br 2 and Cl 2 gases. Compared to the Cl 2 , the Br 2 much more decreases the electrical resistance and E g of the Co-doped graphyne (~ -40.25%). Thus, the Co-doped graphyne may selectively recognize the Br 2 gas in the presence of Cl 2 . The computed recovery time value for Br 2 from the surface of the Co-doped graphyne is 36.4 s , which shows that the graphyne, as a sensor, benefits from a short recovery time to detect Br 2 .