Mechanism of adsorption of hazardous gases by MoTe2 monolayers modified with nanoclusters

Abstract

For the detection and monitoring of hazardous gases, for which two-dimensional material gas-sensitive elements have excellent gas-sensitive properties, the adsorption behavior and electrical response to hazardous gases (NO2 and SO2) revealed by MoTe2 monolayers modified by Cun, Agn and Aun (n = 1 to 4) are investigated in this article using first principles. To better simulate the situation under realistic doping, the number of nanoclusters doped ranges from 1–4, while the most stable calculated structure is chosen based on the formation energy. Calculations of the energy band structure, work function, density of states, frontier molecular orbitals and other electronic properties of the adsorbed systems show that the introduction of metal atoms effectively improves the electrical conductivity of the MoTe2 monolayer, with significant improvements for the gas-sensitive response, as well as increasing the adsorption capacity of the gas. The adsorption strength for NO2 molecules is higher than that for SO2 molecules in the three atom-doped systems. By analyzing the electronic and adsorption properties, it is found that Cu atoms show excellent properties among the three metal atoms, especially the Cu3 system has good adsorption and desorption properties for gases. These studies provide a theoretical basis for preparing high-performance MoTe2 gas-sensitive elements with selectivity and sensitivity for detecting and removing hazardous gases.