Vacancy engineering and lithium functionalization of plumbene for CO2 sensing

Plumbene, the lead (Pb) counterpart of graphene, has recently had a major impact by broadening the exclusive roster of two-dimensional (2D) materials. Here, we report the CO 2 gas sensing performances of pristine, vacancy (Pb-vac), lithium (Li)-doped (Pb − Li ), Li-decorated pristine (Pb + Li ), and Li-decorated vacancy (Pb + vac+Li ) plumbene sheets, as calculated using density functional theory (DFT). Our study reveals that the CO 2 interaction with pristine and Pb − vac sheets falls in the category of weak physisorption with an interaction energy (E int ) of -16.4 and − 15.4 kJ/mol, respectively. While the E int of CO 2 at Pb − Li , Pb + Li and Pb − vac+Li sheets are − 27.8, -34.5 and − 32.5 kJ/mol, respectively. The sensing performance is studied through work function, recovery time, electrical conductivity, and sensitivity parameters. All these parameters suggest that Pb − Li is the most favorable plumbene sheet for CO 2 gas sensing application due to a suitable work function shift (0.062 eV), a conductivity drop (46.1%), and good recovery time (6.90 × 10 − 8 sec).