Plasmon-activated NO2 sensor based on Au@MoS2 core-shell nanoparticles with heightened sensitivity and full recoverability

Developing high-performance gas-sensing devices based on transition metal dichalcogenides (TMDs) has sparked significant research interest in efficient detection of hazardous gases at room temperature . Considering that the gas-sensing performances of TMDs-based sensors can be effectively improved by the localized surface plasmon resonance (LSPR) effect of decorated noble-metal nanoparticles, herein, we explored the LSPR effect on gas-sensitive features via the design of a visible-light-assisted gas sensor using Au@MoS 2 core-shell heterostructures as sensitive materials. The internal connection between the optical absorption and the gas-sensing properties of Au@MoS 2 heterostructures was investigated. Intriguingly, under the activation of indoor white-light, the optimized Au@MoS 2 sensor displayed an enhanced response by more than 8 times and elevated recoverability from 60% to 98% almost without baseline shift as compared with the pure MoS 2 gas sensor for the detection of NO 2 (1 ppm). The combination of experimental and theoretical analysis indicates that the improved gas-sensing performances can be primarily attributed to the effective amplification of the light absorption efficiency of MoS 2 induced by the LSPR effect from the Au nanoparticle cores. These results imply a potential application in monitoring NO 2 gas at room temperature and open up an effective thoughtway for developing high-performance visible-light-modulated gas sensors.