Chemisorbed CO2 molecules on ZnO nanowires (100 nm) surface leading towards enhanced piezoelectric voltage

Absract Here, we have studied the behavior of ZnO based piezoelectric mechanical transducer in the presence of CO2. We have analyzed reduction-oxidation mechanism of CO2 gas on ZnO nanowire surface and studied its behavior for the enhancement piezoelectric output voltage. Rise in piezoelectric potential for various CO2 exposures time intervals from 30min to 3 h has been observed. Chemiresistive behavior of CO2 modified ZnO nanowires, is being explained by the generation of high piezoelectric voltage. ZnO nanowires based nanogenerator has been exposed to 30 min, 60 min, 90 min, 120 min and 3 h in a sealed chamber at 20 ppm, corresponding output piezoelectric voltages of 503.9 mV, 1.15 mV, 1.559 V and 1.795 V have been recorded respectively by using Picoscope 5204. It has also been observed that output voltage value has been saturated after 2 h of CO2 exposure. ZnO nanowire based VING (vertically integrated nanowire generator) structure is being used for the study under minute external force of ? 100 nN. Growth orientation of ZnO nanowires has been ensured along c-axis perpendicular to substrate