Enhanced gas-sensing performance at room temperature and electrical properties of polyaniline–Ni 0.6 Zn 0.4 Fe 2 O 4 nanocomposites

In this work, polyaniline–nickel–zinc–ferrite nanocomposites were synthesized by the in situ polymerization method by varying the concentrations of Ni_0.6Z_0.4Fe₂O₄ nanoparticles in the polyaniline matrix (10, 20, 30, 40, and 50 wt%). The synthesized nanocomposites were subjected to structural characterizations viz., X-ray diffraction, Fourier-transform infrared spectroscopy, and field-emission scanning electron microscopy techniques. Fourier-transform infrared spectroscopy and X-ray diffraction spectral studies reveal the presence of characteristic bands of both polyaniline and Ni_0.6Z_0.4Fe₂O₄ nanoparticles and the formation of their composites is confirmed with the interfacial interaction of Ni_0.6Z_0.4Fe₂O₄ nanoparticles in the polyaniline systems. The field-emission scanning electron microscopy images of polyaniline–Ni_0.6Z_0.4Fe₂O₄ nanocomposites show a symmetric morphological variation of Ni_0.6Z_0.4Fe₂O₄ nanoparticles compared to polyaniline. The electrical properties of the prepared samples were studied in the frequency range of 100 Hz–5 MHz at room temperature. The gas-sensing performance of the nanocomposites was studied at room temperature for butane gas. The polyaniline–10 wt% Ni_0.6Z_0.4Fe₂O₄ nanocomposite shows maximum sensing response (109%) at room temperature for 5000 ppm of butane gas with a good response of 28 s and recovery time of 31 s. The stability of the prepared sample was tested for 60 days.