Adsorption and Sensing of CO₂, CH₄ and N₂O Molecules by Ti-Doped HfSe₂ Monolayer Based on the First-Principle

Abstract

With the continuous emission of greenhouse gases, the greenhouse effect is becoming more and more serious. CO2, CH4, and N2O are three typical greenhouse gases, and in order to limit their emissions, it is imperative that they are accurately monitored. In this paper, the doping behavior of Ti on the surface of HfSe2 is investigated, based on the first-nature principle. Additionally, the parameters of adsorption energy and the transfer charges of Ti−HfSe2 for CO2, CH4, and N2O are calculated and compared, while the sensing characteristics of Ti−HfSe2 are analyzed. The results show that the structure is most stable when Ti is located above the lower-layer Se atom. The CO2 and N2O adsorption systems with large adsorption energies and transfer charges are a chemical adsorption, while the CH4 system is a physical adsorption with small adsorption energies and transfer charges. In addition, Ti−HfSe2 has a good sensitivity and recovery time for CO2 at 298 K, which is feasible for industrial application. All the contents of this paper provide theoretical guidance for the implementation of Ti−HfSe2 as a gas-sensitive material for the detection of greenhouse gas components.

Keywords

• greenhouse gas
• first-principle
• Ti−HfSe₂
• adsorption