Potential application of a defective NiCl2 monolayer as a toxic gas sensor: a computational study

Abstract

Utilizing density functional theory (DFT) calculations, we systematically explored the potential of the defective NiCl₂ nanosheet with Cl vacancies (V_Cl-NiCl₂) as a gas sensor for the detection of H₂, CO₂, NO, O₂, H₂O, CO, and NO₂ gases. The results revealed that NO, O₂, H₂O, CO, and NO₂ can be chemisorbed on Ni sites around Cl vacancies with significant adsorption energy (−0.66 to −1.83 eV), accompanied by a considerable amount of charge transfer and an obvious change in the electronic and magnetic properties of the V_Cl-NiCl₂ system. In particular, due to the short recovery times, we predicted that V_Cl-NiCl₂ could be utilized as a promising gas sensor for CO at 398 K and O₂ under ambient conditions. Our results not only further expand the potential application of NiCl₂ monolayers as a gas sensor, but also offer new options for developing candidate detection materials for toxic gases.