Abstract
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 of 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 (similar to -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.