Ultrasonic process parameter of ZnO-nano sensor on toluene detection

ZnO nanorod sensors were fabricated by sonochemical method with normal temperature and pressure to measure the VOC gas of indoor air pollution. In order to increase the sensitivity, a substrate was improved and set the parameters about solution concentration, irradiation time in ultrasound procedure. The nanorod morphology of each sensor studied over the FE-SEM. The diameter and length of nanorod can be controlled by two parameters. In addition, it observed the sensitivities of sensors upon exposure to toluene gas. The sensitivity is different according to each morphology of ZnO nanorod, the best condition of sensor which has good sensitivity was 0.01 M, 90 min because longer nanorod has larger effective surface areas and it makes the more chance to absorptiondesorption between oxygen and target gas. Furthermore, added Pt, Au helped to improve the sensitivity of sensor and the sensor had a good reproducibility.