A DFT study of toxic gases (NH3, C2H2, NO) adsorption and detection on metal oxides (CuO, Ag2O, In2O3) modified MoTe2 monolayer

In this study, metal oxides (CuO, Ag2O, In2O3) modified MoTe2 were selected to investigate its adsorption and detection properties for three typical industrial toxic gases (NH3, C2H2, NO). Reaction mechanism is reported in terms of adsorption energy, energy band, charge density difference (CDD), density of states (DOS), and molecular orbit based on the first-principles density functional theory (DFT). And the practical application possibility is further explored in conjunction with desorption performance. According to the results, both CuO and Ag2O modified MoTe2 well upgrade the adsorption performance of the three gases to mostly intense chemisorption, while a remained level of physical adsorption performance in In2O3-MoTe2. The Eads of NH3 and C2H2 on CuO-MoTe2 monolayer are −1.302 eV and −1.110 eV, and a profitable desorption in quite short time can be achieved after artificial heating, making CuO-MoTe2 a suitable recyclable heater-type sensor for NH3 and C2H2. For the Ag2O-MoTe2 monolayer, its striking Eads (−2.480 eV) for C2H2 is about 10 times of the original with a hard desorption even in high-temperature environments, making it possible to be applied as a dedicated scavenger for C2H2. Moreover, its Eads (−3.028 eV) about 2.6 times higher for NO enables it to be a reliable NO adsorbent that can be employed at room temperature.