Surface acoustic wave ammonia sensor based on ZnS mucosal-like nanostructures.

Mucosal-like ZnS nanostructures were synthesized on surface of ST-cut quartz surface acoustic wave (SAW) device using a chemical bath deposition method for ammonia sensing applications. Results showed the SAW device with ZnS mucosal nanostructures achieved a good sensitivity, e.g., with a frequency shift of ~190 Hz upon exposure to 1 ppm ammonia gas. This is mainly attributed to the large specific surface areas and more active sites on the surfaces of the ZnS mucosal nanostructures. Selectivity of the SAW device with the ZnS mucosal nanostructure for ammonia sensing was excellent in comparisons with those for other types of gases such as hydrogen sulfide, hydrogen, nitrogen dioxide, carbon monoxide and ethanol. Unlabelled Image • Mucosal-like ZnS nanostructures were deposited on surface of SAW device for sensing ammonia. • The SAW device with ZnS mucosal nanostructures achieved a good sensitivity and selectivity to ammonia. • The negative frequency shift of SAW sensor is associated to the effects of mass loading and electrical loading. [ABSTRACT FROM AUTHOR]