Expanding Selectivity Functionality of a ZnO Nanotetrapod-Based Volatile Organic Compound Sensor Using Au Nanoparticle Decoration

Gassensors with multiselectivity are drawing increasing attentionand sensors with temperature-tuned dual selectivity have been developed.Because Au nanoparticles (NPs) can lower the activation barrier forsensing reactions, herein, Au NP decoration was used to expand theselectivity range of a ZnO nanotetrapod (NTP)-based sensor. A temperature-tunedtriselectivity sensor based on Au NP-ZnO NTPs was developed.The sensor exhibited enhanced selectivity for formaldehyde when theoperation temperature was <200 degrees C, ethanol when the operationtemperature was between 200 and 340 degrees C, and acetone when theoperation temperature was >400 degrees C. Additionally, Au NP decorationincreased the magnitude of response and decreased the optimal detectiontemperature of the sensor. This work demonstrates that Au NP decorationis an efficient approach for improving the performance of semiconductor-basedgas sensors with temperature-tunable selectivity.