Effect of Morphology on the Electrical Conductivity of Polyaniline as Potential Photocatalyst

Abstract

Materials with different morphologies may possess different electrical conductivities which contribute to different photodegradation efficiencies. Hence, it is crucial to control the morphology of the photocatalysts. Therefore, the effect of PANI morphology on the electrical conductivity is investigated in this research. PANI with different morphologies have been fabricated via template-free method in the presence of various dopants and utilized as photocatalyst. The different morphologies of PANI are expected to yield different photocatalytic ability towards pollutants such as dyes in wastewater due to their differences in surface area and charge carriers (conductivity). The chemical structures and oxidation states of the prepared photocatalysts were confirmed by FTIR and UV–Vis spectra. The electrical conductivity of photocatalysts were measured using four probe point method on PANI pellet while the morphological studies were investigated using FESEM. From the results, nanotube-PANI exhibited the highest electrical conductivity (1.22 × 10^–2 S/cm), followed by nanosphere-PANI (1.16 × 10^–2 S/cm), nanofiber-PANI (4.59 × 10^–3), star-PANI (5.84 × 10^–4 S/cm) and leaf-PANI (5.57 × 10^–3 S/cm). PANI with nanotube structure is more conductive as the nanostructure has a longer conjugated polymer chain than the other micro/nanostructures and hence it can facilitate electron transport and subsequently enhances electrical conductivity of PANI.