Highly enhanced performance for sensing by monolayer 1T’ WS₂ with atomic vacancy

Superior gas capture and detection performance play an important role in gas sensing materials. Effects of atomic vacancy defects on intrinsic properties of material are also not negligible. Here we firstly discuss gas adsorption behavior of defective 1T’ WS₂ monolayer. We take toxic NO₂ gas as an example to compare adsorption effects between defective and perfect 1T'WS₂ monolayer. First-principles study based on density functional theory(DFT) is carried out to act as the theoretical basis. These results demonstrate vacancy defects could enhance adsorption stability of 1T’ WS₂ monolayer, which provide lower adsorption energy, more charge transfer and more overlaps of density of states. Therefore, vacancy defects make 1T’ WS₂ monolayer possess more outstanding surface activity and adsorption performance. This can also offer theoretical support for the improvement of nanomaterials applied in those high performance gas sensing devices.