Study on SO2 and Cl2 sensor application of 2D PbSe based on first principles calculations.

ABSTRACT

In this paper, we use 2D PbSe to design a gas sensor to monitor the presence of SO2 and Cl2. We use first principles to verify the feasibility of this material, such as atomic structure, band gap, differential charge density and Bader charge. The results show that 2D PbSe can distinctly adsorb SO2 and Cl2. Furthermore, the adsorption of SO2 and Cl2 will affect the electronic structure of 2D PbSe, and some electrons in the PbSe are transferred to gas atoms. The band gap of the system after adsorption is smaller than that of the PbSe before adsorption. The band gap of single layer PbSe decreases by 41.92% after SO2 adsorption and 60.61% after Cl2 adsorption. The band gap of multi-layer PbSe decreases by 72.97% after SO2 adsorption and 43.24% after Cl2 adsorption. This shows that single layer PbSe is more sensitive to Cl2 and multi-layer PbSe is more sensitive to SO2. It provides a potential possibility for designing gas sensors for SO2 and Cl2 based on 2D PbSe.