Enhanced gas-sensing to low-concentration ethanol gas from 3-dimensional (3D) urchin-like ZnO micro/nanospheres

Highly sensitive and long-term stable ethanol gas sensors based on 3D urchin-like ZnO micro/ nanospheres are synthesized. The formation mechanism of the 3D urchin-like ZnO structure is analyzed. The 3D urchin-like ZnO micro/nanospheres sensor displayed a high sensitivity of 15.0, a fast response time of 14 sec, and a recovery time of 7 sec when detecting 200 ppm ethanol gas at the optimal operating temperature of 280 °C. Moreover, the sensor is in the low concentration of ethanol gas for 450 days, in this case, the sensitivity of the sensor is 5.9, when detecting 200 ppm ethanol gas at an operating temperature 280 °C. The prepared 3D urchin-like ZnO micro/nanospheres have higher response strength to low-concentration ethanol gas and still have good stability after long-term storage