Abstract
Ammonia (NH(3)) is a hazardous gas requiring rapid detection at room temperature for practical environmental and agricultural monitoring. Herein, we report a flower-like CNTs@MoS(2) core-shell heterostructure synthesized via a facile hydrothermal process for room-temperature NH(3) sensing. Structural analyses confirm uniform MoS(2) nanosheets anchored on the CNT networks, forming well-defined p-n heterojunction interfaces that facilitate efficient charge transport. This architecture effectively combines the high surface activity and gas adsorption capability of MoS(2) with the superior electrical conductivity of CNTs, promoting rapid charge transfer and enhanced sensing performance. The optimized sensor achieves a high response of 94% toward 500 ppm of NH(3) with rapid response and recovery times of 36 and 68 s, respectively. Additionally, humidity-assisted interfacial charge transfer further improves the sensor response under high relative humidity. Long-term stability tests demonstrate ∼80% response retention after 150 days. This study elucidates the dominant role of MoS(2) and the synergistic charge modulation enabled by CNTs@MoS(2) heterostructures, providing a clear design strategy for high-performance NH(3) gas sensor at room temperature.