Adsorption of indoor hazardous gases on Zn and ZnO modified MoS2 monolayers: A first-principles study

Abstract

The detection of indoor hazardous gases is crucial for safeguarding human health, while MoS${}_2$ shows great potential in absorbing harmful indoor gases. However, the adsorption performance of MoS${}_2$ monolayer is still very limited. In this study, first-principles theoretical calculations are employed to investigate the adsorption performance of Zn and ZnO modified MoS${}_2$ towards NH${}_3$, HCHO and C${}_6$H${}_6$. We systematically examined the thermal stability, gas adsorption mechanisms and practical application potential of three modified MoS${}_2$ (Zn-MoS${}_2$, ZnO-MoS${}_2$ and ZnO+Zn-MoS${}_2$). The results reveal that modified MoS${}_2$ exhibits excellent conductivity and gas adsorption capabilities. Specifically, both ZnO-MoS${}_2$ and ZnO+Zn-MoS${}_2$ exhibit strong chemisorption with the HCHO molecule, demonstrating adsorption energies of -1.915 eV and -1.985 eV, respectively. Furthermore, when the temperature reaches 348 K, ZnO-MoS${}_2$ shows high sensitivity (249%) and excellent recovery capability (4.2 S) towards C${}_6$H${}_6$, indicating its potential advantages in the development of recyclable C${}_6$H${}_6$ sensors. This research provides theoretical insights into utilizing MoS${}_2$-based sensors for detecting indoor hazardous gases.