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

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 PtSe2. It is found that both N-2 and O-2 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 N-2 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 O-2 adsorption. In addition, notable changes in the optical absorption spectra of the PtSe2 with Pt@Se defect are induced upon N-2 adsorption, which also occurs for PtSe2 with Pt and Se vacancies and Pt@Se anti-site defects upon O-2 adsorption. These results demonstrate that PtSe2 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.