Synthesis, characterization, electrical and sensor behavior of PANI/In₂O₃ nano composites

Indium oxide (In₂O₃) nanoparticles were successfully prepared by sol-gel method. Nanocomposites of polyaniline (PANI) and Indium oxide (In₂O₃) have been synthesized using insitu polymerization method for different concentrations of nano In₂O₃ powder. The formation of polymer nanocomposite and changes in its structural and micro structural properties of the materials were investigated by X-ray diffractometry (XRD) and Fourier infrared spectroscopy (FTIR) techniques. The surface morphology of PANI–In₂O₃ nanocomposite was elucidated using Scanning Electron Microscopy (SEM). DC conductivity studies of PANI-In₂O₃ composites for different weight percentage (wt%) show thermally activated behaviour. The conductivity was found to increase with the increase in temperature indicating the semiconducting behaviour of all the compositions. Maximum conductivity was observed in 30 wt% of In₂O₃ in polyaniline. On exposure of the composites to liquefied petroleum gas (LPG), increase in resistance was observed with the increase in gas concentration. Maximum sensitivity for gas sensing was observed in the composite of 50 wt% In₂O₃ in polyaniline.