Efficient N₂- and O₂-Sensing Properties of PtSe₂ With Proper Intrinsic Defects

Developing efficient N₂ and O₂ gas sensors is of great importance to our daily life and industrial technology. In this work, first-principles calculations are performed to study the N₂ and O₂ gas-sensing properties of pure and defected PtSe₂. It is found that both N₂ and O₂ adsorb weakly on pure PtSe₂, and adsorption of the molecules induces negligible changes in the electrical and optical properties. Whereas the Pt@Se anti-site defect significantly improves the N₂ adsorption capacity of PtSe₂ 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 O₂ adsorption. In addition, notable changes in the optical absorption spectra of the PtSe₂ with Pt@Se defect are induced upon N₂ adsorption, which also occurs for PtSe₂ with Pt and Se vacancies and Pt@Se anti-site defects upon O₂ adsorption. These results demonstrate that PtSe₂ with the corresponding defects can be both excellent electrical and optical sensors for detecting N₂ and O₂ gases. Our work offers a new avenue for preparing efficient gas sensors.