Synthesis of PANIHCl/ZnO conductive composite by in-situ polymerization and for humidity sensing application

Abstract

In this study, the conductive polyaniline doped by hydrochloric acid (PANIHCl)/zinc oxide (PANIHCl/ZnO) conductive composite was synthesized by in-situ polymerization. The conductive PANIHCl solution or PANIHCl/ZnO conductive composite solution was coated on an interdigital electrode (IDE) by drop coating to make a humidity sensor. The synthesis process, chemical structure, surface morphology, and humidity sensing characteristics of PANIHCl and PANIHCl/ZnO conductive composite were investigated. Field emission scanning electron microscope (FE-SEM) images suggested that the surface morphology of the PANIHCl/ZnO conductive composite is fibrous or rod-shaped, with a diameter of about 100 nm. The sensing responses of PANIHCl and PANIHCl/ZnO were 40% and 87%, respectively. The humidity sensing response of PANIHCl/ZnO as the sensing material was more than twice that of PANIHCl as the sensing material. The response time (Tres) is 13 s, and the recovery time (Trec) is 171 s. Research results showed that adding ZnO to PANIHCl can effectively improve the response of the sensor to humidity detection. Therefore, using PANIHCl/ZnO conductive composite as a sensing material will have great potential for application in humidity or other gas sensing devices.