Fast and complete recovery of TMDs-decorated rGO fiber gas sensors at room temperature

Abstract

Transition metal dichalcogenides (TMDs) possess great potential for use in gas sensing applications because, in contrast to conventional metal oxides, they have unique semiconducting properties with band gaps that can be tuned by adjusting thickness and composition. However, one issue is that their recovery time at room temperature is too long for them to be used practically in sustainable sensing applications. We found that incorporating Se atoms weaken interactions with gas molecules compared to when S atoms are used alone, therefore, the responsivity, as well as the recovery properties, of MoSxSe2-x sensors were significantly enhanced by increasing the ratio of Se to S. Herein, we demonstrate high-performance gas sensors that are based on reduced graphene oxide (rGO) fibers coated with MoSxSe2-x, the fabricated sensor could efficiently refresh its surface to allow fast, complete recovery at room temperature. Furthermore, it was shown that the porosity of rGO fibers with their large surface-to-volume ratio leads to enhanced sensing at room temperature.