Highly Efficient Humidity Sensor Based on Sulfuric Acid Doped Polyaniline-Copper Oxide Composites

The use of humidity sensors in environmental monitoring application such as the creation of safe, comfortable, and cost-effective environment has been the subject of interest right from the beginning. The current study is focused on the organic-inorganic composite material as humidity sensor. Polyaniline (PANI) and its composites with copper oxide (PANI-CuO) doped with sulfuric acid (H2SO4) are prepared by the in-situ polymerization method. Structural features are investigated by different techniques including Ultraviolet/Visible (UV/Vis), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), and Scanning Electronic Microscopy (SEM). The structural characterizations confirm the emeraldine salt (ES) form of the PANI doped with H2SO4. The conductivity measurements are recorded by using a four-probe conductivity meter, which indicates higher conductivity of the composites as compared to neat PANI. The cyclic voltammetry of the synthesized PANI and its composites with CuO is performed to study the redox properties. The humidity sensing properties in terms of measurement of capacitance are studied by using an LCR meter, which show the linear increase in the capacitance of the prepared composites. The sensor shows fast response and recovery with high stability.

Automated summary

The study focuses on the use of an organic-inorganic composite material as a humidity sensor. The structural characteristics, conductivity, redox properties, and humidity sensing properties of the composite are investigated using various techniques. The sensor shows fast response, high stability, and linear increase in capacitance, indicating promising potential for environmental monitoring applications.