Inorganic Acid Doped Polyaniline Based Carbon Monoxide (Co) Sensor

Simple in situ chemical oxidation method was employed to prepare different molar of HCl doped DL−PLA/PANI composites using AnHCl as precursor. Surface morphology, ATR−FTIR, UV–Visible, and band gap were studied. PANI nanowires with different diameter and smooth surface were observed for composites. The lowest direct band gap was found to be 1.68 eV for 2 (M) HCl doped DL−PLA/PANI. DC conductivity at room temperature was measured and followed the ohmic behaviour. The calculated highest DC conductivity at room temperature was found to be 0.1628 × 10−2 (S/cm) for 2 (M) HCl doped DL−PLA/PANI. Temperature variation (70−300 K) DC conductivity without magnetic field of as prepared composites was analysed using linear four probe techniques and showed semiconducting nature. The conductivity in the range of temperature (70−300 K) follows 3D VRH hopping mechanism. In kivelson model, the exponents are increased with increasing dopant concentration and was obeyed the power law. MR of the prepared DL−PLA/PANI composite films is strongly dependent on temperature, magnetic field, and concentration of HCl dopant. Negative MR is discussed in terms of a wave function−shrinkage effect on hopping conduction. In addition, we were discussed the response of carbon monoxide (CO) gas with polyaniline-based sensor materials.