Exploring the sensing ability of B‐ and Si‐doped WS2 monolayer toward CO and NO gas

Abstract

AbstractSearching for new two‐dimensional (2D) materials to capture toxic gas molecules has drawn great attention from scientific community. In this work, the adsorption of CO and NO molecules on B‐ and Si‐doped WS2 monolayer (B:WS2 and Si:WS2) has been explored using first‐principles calculations. Pristine WS2 monolayer is a non‐magnetic semiconductor with an energy gap of 1.81 eV. It is magnetized upon doping with B atom to form a half‐metallic material, meanwhile the paramagnetic nature is preserved upon Si doping. CO and NO molecules are weakly physisorbed on pristine WS2 monolayer. Doping strategies enhance significantly the adsorption process decreasing drastically the adsorption energy. The adsorbed gas molecules alter considerably the fundamental properties of the doped systems. Specifically, the magnetic properties of B:WS2 system are quenched by both CO and NO molecules to form paramagnetic metallic and semiconductor materials, respectively. CO adsorption increases the energy gap of Si:WS2 system, meanwhile the adsorbed NO molecule induces significant magnetism, leading to the emergence of the half‐metallicity. Results presented herein may recommend B‐ and Si‐doped WS2 monolayer as promising candidates to detect and capture CO and NO molecules. Moreover, doping strategy may be used to functionalize 2D transition metal dichalcogenides for toxic gas sensing.