One-dimensional Mo6S6 nanowire for potential application in gas sensing

Nanowires have emerged as excellent candidates for gas sensing due to their superior specific surface area and active sites. In this work, we focused on Mo6S6 nanowires and systematically investigated the adsorption characteristics of nine common gases in air (CO, CO2, CH4, H2O, H2S, SO2, NO, NO2, and NH3) on their surfaces. This included the analysis of adsorption energy, adsorption distance, charge transfer amount, and adsorption type. The results indicated that CO2, CH4, H2O, H2S, and SO2 exhibited typical physical adsorption on Mo6S6 nanowires, while the other four gases (CO, NO, NO2, and NH3) underwent chemical adsorption. Calculations of the electronic structure revealed that physical adsorption had almost no impact on the electronic structure of Mo6S6 nanowires. In contrast, chemical adsorption directly affected the electronic structure near the Fermi level of Mo6S6 nanowires due to charge transfer between the gases and the nanowires, thereby influencing their transport properties. Finally, quantum transport property calculations based on the nonequilibrium Green's function revealed that the adsorption of CO, NO, NO2, and NH3 on the surface of Mo6S6 nanowires reduced their current density, making them promising candidates for gas detection. Our work provides theoretical support for the application of Mo6S6 nanowires in the field of gas sensing.