Self-powered ethanol gas sensor based on the piezoelectric Ag/ZnO nanowire arrays at room temperature

Nowadays, sensors are increasingly pursuing the characteristics of miniaturization and high sensitivity. A self-powered ethanol gas sensor based on Ag/ZnO nanowire arrays prepared by two-step hydrothermal method is reported. The piezoelectric output of Ag/ZnO nanowire arrays serves as power supply for self-powered sensors, which also can detect various concentrations of ethanol gas at room temperature. It is verified that the piezoelectric output capability of the sensor increases greatly after Ag-doping. Upon exposure to ethanol gas with concentration increasing from 10 to 1000 ppm, the piezoelectric output voltage for the sensor decreases from 1.75 to 0.2 V. The reason is attributed to the addition of Ag, which plays a strong catalytic role. At the same time, Schottky barrier is formed between Ag and ZnO, which affects the piezoelectric gas sensing performance and accelerates the reaction. The results show that this method is a feasible way to realize self-powered gas sensor for various applications.