Electrochemically fabricated Polyaniline/Reduced Graphene Oxide nanocomposite films for enhanced photocatalytic and antibacterial applications

In this work, hybrid nanocomposite thin films composed of polyaniline (PANI) and reduced graphene oxide (rGO) were successfully fabricated on indium tin oxide (ITO) substrates through an electrochemical polymerization approach. Reduced graphene oxide was prepared from graphene oxide using a modified Hummers method and subsequently incorporated into the growing PANI matrix during electropolymerization. The structural, morphological, optical, and photoelectrochemical characteristics of the obtained nanocomposites were investigated using field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), UV–Visible spectroscopy, and photocurrent measurements. Morphological observations revealed the formation of well-defined PANI nanorods with diameters ranging from approximately 50 to 100 nm, while XPS analysis confirmed the successful integration of rGO within the polymer framework. Consequently, the incorporation of rGO significantly enhanced the photoelectrochemical behavior of the material, leading to an increase in photocurrent density from 7 to 13 mA cm⁻² due to the efficient charge transport and reduced recombination of photogenerated charge carriers provided by the conductive graphene network. Furthermore, the photocatalytic performance of the nanocomposite films was evaluated through the degradation of Congo red dye under acidic conditions, where the PANI-rGO system exhibited superior photocatalytic activity compared with pristine PANI, achieving a dye removal efficiency close to 90%. Additionally, chitosan-modified ITO/PANI and ITO/PANI-rGO films were assessed for their antibacterial properties against Escherichia coli, demonstrating notable antibacterial activity and indicating their potential for multifunctional environmental applications. Overall, these findings highlight the synergistic effect between PANI and rGO, demonstrating the suitability of the developed nanocomposites for photocatalytic wastewater treatment and antimicrobial surface coatings.