Pt Nanoparticle-Modified SnO2–ZnO Core–Shell Nanosheets on Microelectromechanical Systems for Enhanced H2S Detection.

Pt nanoparticle (NP)-modified SnO₂–ZnO (SnO₂–ZnO–Pt) core–shell nanosheets (NSs) for hydrogen sulfide (H₂S) gas sensing were successfully synthesized via atomic layer deposition, hydrothermal method, and magnetron sputtering. More importantly, the SnO₂–ZnO–Pt NS sensing materials were synthesized in situ on microelectromechanical system (MEMS) devices, which are expected to be high-performance gas sensors with superior sensitivity, great selectivity, good reproducibility, and low power consumption. To be specific, the SnO₂–ZnO–Pt NSs displayed a high sensitivity (R_a/R_g) of 30.43 and an excellent selectivity when detecting 5 ppm H₂S at an operating temperature of 375 °C. Their rate of resistance change was 29.43, which was about 24 and 9 times those of the pristine SnO₂ NS (∼1.25) and SnO₂–ZnO core–shell NS (∼3.43) sensors, respectively. These substantially improved sensing properties could be mainly attributed to the formation of heterojunctions, catalytic sensitization effect, and increased specific surface area of Pt NP modification. Thus, the proposed SnO₂–ZnO–Pt NS gas sensors demonstrate great potential as a high-performance sensing material for application in H₂S gas sensors. [ABSTRACT FROM AUTHOR]