Highly efficient Zinc Oxide nanostructure based gas sensor for domestic application

Abstract

In this work, Zinc Oxide (ZnO) nanorods with high surface to volume ratio were fabricated through the hydrothermal synthesis process on a glass slide and highly conductive alumina ceramic based gold interdigitated electrode (IDE). The ZnO nanorods structure on substrates were characterized through X-ray diffraction (XRD) and UV absorption spectroscopy followed by growth verification by Scherrer’s equation. The sensitivity characterization of fabricated sensor was determined for 2000 ppm and 4000 ppm natural gas in the air through high resistance electrometer at room temperature. The 2000 ppm concentration of gas shows 11.3% sensitivity, response time of 66 seconds and recovery time of 92 seconds to the sensor. The 4000 ppm concentration of gas shows 64% sensitivity, the response time of 106 seconds and a recovery time of 174 seconds to the sensor. The higher sensitivities with slow response and recovery times exhibit the behavior of redox reactions of sensor surface to the higher concentration of natural gas. The minute reduction in resistance and with the fast response and recovery time of the sensor show the 11.3% sensitivity to lower concentration. The more concentration of natural gas in the air would show a higher sensitivity of the sensor. The experimental results indicate the growth of ZnO nanorods on substrates and their sensitivity to natural gas.