Performance of Polyaniline Thin Film as a Functional Material of Acid Vapor Sensors

Abstract

Polyaniline (PANI) is a conductive polymer that can be produced by the electrodeposition process. The purpose of this research is to evaluate the performance of PANI sensors on hydrochloric acid (HCl) and acetic acid (CH3COOH) vapor using a scan rate of 100 mV/s and ten cycles, a thin PANI layer was created on the surface of the ITO substrate. The PANI spectroscopic test results before and after CH3COOH vapor exposure revealed no differences and remained within the PANI functional group range. A four-point probe (FPP) test was performed to evaluate the sensing performance of the PANI thin film against analyte gas. The results of recovery time, response time, and sensitivity tended to increase as analyte concentration increased. The quickest CH3COOH sensing (1 ppm) has a reaction time of 29.7 seconds, a recovery time of 21.9 seconds, and a sensitivity of 5.11%. The greatest CH3COOH sensing (10 ppm) resulted in a reaction time of 50.3 seconds, a recovery time of 39.7 seconds, and a sensitivity of 13.64%. The reaction time for the lowest HCl sensing (1 ppm) was 42.6 s, the recovery time was 32.4 s, and the sensitivity was 7.82%. The greatest level of CH3COOH sensing (10 ppm) resulted in a response time of 60.6 s, a recovery time of 55.3 s, and a sensitivity of 16.31%. As a result, the PANI thin film is a functional material for acid gas sensors.