Adsorption and gas sensitivity of Janus SnSSe monolayers doped with transition metals to harmful gases: First principles studies

Abstract

Sensitivity detection of toxic gases has always been a very needed technology, and it is particularly important to prevent the gas from causing damage to the human body. To meet the demand, we propose TM atom-doped Janus SnSSe monolayers as a promising gas sensing material for the detection of three typical hazardous gases (CO, NO and CO2). In this paper, density functional theory is used to systematically study the adsorption process of the target gas on the surface of the pristine and modified substrate. By comparing the formation energy of the two sides of the TM-SnSSe monolayer, the TM atom doped on the surface of Se is more stable. Compared with SnSSe monolayers, the Os-SnSSe system has the best adsorption performance for CO and the Ru-SnSSe system has the best adsorption performance for NO and CO2. By calculating the density of state, charge density difference, work function and recovery time of each adsorption system, the interaction mechanism between gas molecules and TM-SnSSe is described, and the function and reusability of the sensor materials are explored. The results show that the SnSSe monolayer modified with TM can be used as a kind of gas detection and purification material. The research work in this paper can predict new sulfide sensing materials, increase their application possibility in the field of environmental monitoring, and provide theoretical guidance for the development of promising new sensors.