A DFT study of the adsorption behavior and sensing properties of CO gas on monolayer MoSe2 in CO2-rich environment

Abstract

Context: Carbon monoxide, also known as the “silent killer,” is a colorless, odorless, tasteless, and non-irritable gas that, when inhaled, enters the bloodstream and lungs, binds with the hemoglobin, and blocks oxygen from reaching tissues and cells. In this work, the monolayer MoSe<inf>2</inf>-based CO gas sensors were designed using density functional theory calculation with several dopants including Al, Au, Pd, Ni, Cu, and P. Here, Cu and P were found to be the best dopants, with adsorption energies of −0.67 eV (Cu) and −0.54 eV (P) and recovery times of 1.66 s and 13.8 ms respectively. Cu conductivity for CO adsorption was found to be 2.74 times that of CO<inf>2</inf> adsorption in the 1.0–2.26 eV range. P displayed the highest selectivity, followed by Pd and Ni. The dopants, Pd and Ni, were found suitable for building CO gas scavengers due to their high recovery times of 9.76 × 1020 s and 2.47 × 1011 s. Similarly, the adsorption of CO<inf>2</inf> on doped monolayer MoSe<inf>2</inf> was also investigated. In this study, it is found that monolayer MoSe<inf>2</inf> could be employed to create high-performance CO sensors in a CO<inf>2</inf>-rich environment. Method: The electrical characteristics of all doped MoSe<inf>2</inf> monolayers are obtained using a DFT calculation with the PBE-GGA method from the Quantum ESPRESSO package. The self-consistent field (SCF) computations were performed using a 7 × 7 × 1 k-point grid and a norm-conserving pseudo potential (NCPP) file. To determine electrical conductivity, the semi-classical version of Boltzmann transport theory, implemented in the Boltz Trap code, was used. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.