DFT study on the adsorption of CO, NO2, SO2 and NH3 by Te vacancy and metal atom doped MoTe2 monolayers

Abstract

Based on the first-principles calculation, the adsorption structure and electronic characteristics of CO, NO 2 , SO 2 and NH 3 adsorbed on pure, defective and metal atom doped MoTe 2 monolayer were systematically studied. The original MoTe 2 monolayer and MoTe 2 monolayer containing Te defects can be used as room temperature gas sensors to detect NO 2 gas and SO 2 gas, and the adsorption effect can steadily increase in the simulated working environment. The adsorption behaviors of Ag, Pd and Rh atoms with different doping methods were studied. The calculation results show that the conductivity and chemical activity between metal atoms and gas is improved after doping, resulting in tremendous adsorption energy and charge transfer. Due to the changes in the energy band structure, the density of states, work function and recovery time after adsorption, different doped systems show the potential of high-performance gas sensors at room temperature and high temperature. The research results are significant to the gas sensing mechanism of the modified MoTe 2 monolayer and helpful in exploring the modified MoTe 2 monolayer as a sensing material and gas scavenger. • MoTe 2 containing defects can improve gas adsorption capacity, especially for SO 2 molecules. • Two methods of metal atom doping can improve the chemical activity of gas and substrate. • The adsorption structures under different systems were explored as gas sensors and scavengers.