High Surface Area MoS₂/Graphene Hybrid Aerogel for Ultrasensitive NO₂ Detection

A MoS 2 /graphene hybrid aerogel synthesized with two‐dimensional MoS 2 sheets coating a high surface area graphene aerogel scaffold is characterized and used for ultrasensitive NO 2 detection. The combination of graphene and MoS 2 leads to improved sensing properties with the graphene scaffold providing high specific surface area and high electrical and thermal conductivity and the single to few‐layer MoS 2 sheets providing high sensitivity and selectivity to NO 2 . The hybrid aerogel is integrated onto a low‐power microheater platform to probe the gas sensing performance. At room temperature, the sensor exhibits an ultralow detection limit of 50 ppb NO 2 . By heating the material to 200 °C, the response and recovery times to reach 90% of the final signal decrease to <1 min, while retaining the low detection limit. The MoS 2 /graphene hybrid also shows good selectivity for NO 2 against H 2 and CO, especially when compared to bare graphene aerogel. The unique structure of the hybrid aerogel is responsible for the ultrasensitive, selective, and fast NO 2 sensing. The improved sensing performance of this hybrid aerogel also suggests the possibility of other 2D material combinations for further sensing applications.