Effects of hydrogen peroxide on the electrical conductivity of graphite/polyaniline composites

The effects of hydrogen peroxide (H2O2) on the direct current (dc) electrical conductivity of graphite (G)/polyaniline (PANI) composites are studied. It was found that the conductivity of G/PANI composite reacted with H2O2 decreases with increasing time. Results are confirmed by UV–vis, FTIR absorption measurements, X-ray diffraction analysis and Raman spectroscopy. From X-ray diffraction and Raman spectroscopy measurements we prove that H2O2 affects only PANI but not Graphite particles. After their treatment with H2O2 only G(10%)/PANI, G(20%)/PANI and G(30%)/PANI samples show a semi-conductor behavior. The charge transport mechanisms in these three samples are due to hopping and tunneling and are described by both Mott's three-dimensional variable range hopping model and Sheng's fluctuation induced tunneling model. The transition in the nature of charge transport in G(10%)/PANI, G(20%)/PANI and G(30%)/PANI samples after treatment with H2O2 is caused by disorder and localization, whereas the inverse semi-conductor-metal transition which occurs at above G(30%) in the same samples arises essentially from percolation in G/PANI composites.