Ab-initio study of molybdenum carbide (Mo2C) as an adsorption-based filter

Abstract

Motivated by recent research on adsorption properties of TMCs employed in gas sensing channels, we investigate the adsorption of various poisonous gas molecules (H2S, SO2, CO, NH3, NO, NO2) on various locations of molybdenum carbide (Mo2C) monolayer using density functional theory (DFT). Novel gas sensing characteristics were exhibited by the molybdenum carbide sensors which have not been unveiled by foregoing typical sensing materials. Adsorption energy, adsorption distance, Bader charge, and recovery time are calculated. All the molecules, except NH3 at the Carbon atom and hollow (Ho) site of the monolayer, are chemisorbed on the Mo2C monolayer with high adsorption energies and apparent charge transfer. The electronic properties of Mo2C monolayer before and after the adsorption of gas molecules are analyzed. Furthermore, a versatile gas sensing response is noticed for NO and NO2 gas molecules with higher adsorption energies −3.508 eV and −5.933 eV respectively. Moreover, due to their high adsorption energies and structural stability, TMCs can be availed as channel materials for sensors.