Exploring the adsorption characteristics of toxic CO gas on pristine, defective, and transition metal-doped I-AsP monolayer

Utilizing first-principles calculations based on density functional theory, the adsorption characteristics of toxic carbon monoxide (CO) gas adsorbed on pristine, defective, and transition metal (TM) atoms (Sc, Mn, Fe, Ni, Cu, and Zn)-doped blue arsenic-phosphorene (I-AsP) are investigated to design potential sensing platforms. The pristine and defective monolayers exhibited weak CO gas sensing performance due to weak adsorption and unaltered electronic properties. In contrast, TM-doped monolayers exhibited strong interactions and enhanced the adsorption sensitivity due to their chemisorption behavior towards CO molecule. Furthermore, electronic properties obtained through the spin density of states analysis show significant changes in the adsorption of CO molecules on the doped I-AsP monolayer, influencing electrical conductivity. The significant change in the work function of system monolayers after CO adsorption confirmed that the TM-doped I-AsP monolayer is sensitive to CO gas. Therefore, the TM-doped I-AsP monolayer possesses strong sensitivity to CO gas, among which the Sc and Cu-doped monolayers emerge as promising candidates for toxic CO gas detection.