Investigation of PANI/ZnO nanocomposite for alcohol vapor sensor

The aim of this study is to determine the characteristics of PANI/ZnO nanocomposites and its sensitivity to methanol, ethanol, and butanol at low concentrations. The synthesis process was oxidation polymerization followed by wet mixing. FTIR was used to identify the PANI/ZnO NCs phase, XRD to investigate the PANI/ZnO NCs structure, EDX to analyze the elements, and SEM to examine the sample microstructure. Sensitivity is determined using the four-point probe (FPP) method, which measures the change in resistance of PANI/ZnO NCs when exposed to alcohol vapor. The FTIR analysis results confirmed the presence of C=C stretch (Quinoid) and C-C stretch (Benzenoid) bonds from PANI, as well as ZnO's unique peaks, notably Zn-O-Zn. The PANI/ZnO nanocomposite's diffraction peak at 2θ=21.22° showed amorphous semicrystalline PANI, whereas the peak at 31.75° suggested crystalline ZnO. Elemental analysis revealed that the sample contained N and C elements from PANI, as well as Zn elements from ZnO. Microstructure investigations revealed that the PANI/ZnO NCs had an ovoidal form with an average diameter of 293 nm. PANI/ZnO NCs have been shown to detect methanol, ethanol, and butanol vapors at low levels. When exposed to butanol vapors, the PANI/ZnO NCs exhibit a greater resistance change response than when exposed to other alcohol vapor. Although PANI/ZnO NCs have a higher sensitivity for detecting butanol vapor, they respond faster to methanol vapor than the other two alcohols. The response time was 40 seconds when PANI/ZnO NCs were subjected to methanol vapor at a concentration of 5 ppm, followed by a 20-second recovery period. Furthermore, PANI/ZnO NCs become more sensitive as alcohol vapor concentration increases