Surface Acoustic Wave (SAW) Ammonia Gas Sensor Based on the ZnO Nanorod Array

摘要

Surface acoustic wave (SAW) sensors based on ZnO nanorod array for ammonia detection were investigated at room temperature. The ZnO nanorod array was synthesized by a hydrothermal process. The length and width of the nanorod were 1 μm and 100 nm, respectively. The XRD and AFM characterizations showed that the ZnO nanorod array was highly crystallinity and oriented. Compared to the flat film, the ZnO array had much higher specific surface area, which was beneficial for the gas sensing property. The sensor exhibited a negative frequency shift of 300 Hz to 50 ppm ammonia, and also showed excellent stability, reproducibility at room temperature.