Abstract
Developing efficient N(2) and O(2) gas sensors is of great importance to our daily life and industrial technology. In this work, first-principles calculations are performed to study the N(2) and O(2) gas-sensing properties of pure and defected PtSe(2). It is found that both N(2) and O(2) adsorb weakly on pure PtSe(2), and adsorption of the molecules induces negligible changes in the electrical and optical properties. Whereas the Pt@Se anti-site defect significantly improves the N(2) adsorption capacity of PtSe(2) and induces notable changes in the electrical property. Similar results are also observed for the Pt and Se vacancies and Pt@Se anti-site defects when examining O(2) adsorption. In addition, notable changes in the optical absorption spectra of the PtSe(2) with Pt@Se defect are induced upon N(2) adsorption, which also occurs for PtSe(2) with Pt and Se vacancies and Pt@Se anti-site defects upon O(2) adsorption. These results demonstrate that PtSe(2) with the corresponding defects can be both excellent electrical and optical sensors for detecting N(2) and O(2) gases. Our work offers a new avenue for preparing efficient gas sensors.