Morphological and Elemental Evolution of Moringa oleifera Leaf Extract-Doped Polyaniline Thin Films Fabricated by Spray Pyrolysis for Light-Harvesting Applications

Abstract

This study investigates the morphological and elemental characteristics of green-sensitized polyaniline (PANI) nanocomposite thin films, fabricated using a spray pyrolysis technique with Moringa oleifera leaf extract as a natural dopant. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were employed to analyze the surface structure, aggregation patterns, and elemental composition of thin films doped with varying volumes (0, 5, 10, 15, 20 mL) of the extract. Results indicate that the introduction of Moringa oleifera dye significantly alters the surface morphology of pure PANI, transforming it from a smooth, homogeneous film to a rougher, clustered texture. EDS confirmed successful dye integration, showing a progressive increase in oxygen content from approximately 2% in pure PANI to 25% in composites doped with 20 mL of the extract. This oxygen enrichment indicates functionalization with oxygenated phytochemical groups from the natural extract. These morphological changes enhanced surface area, porosity, and cluster formation that are directly contribute to improved light-trapping capabilities. In conclusion, Moringa oleifera leaf extract serves as an effective, eco-friendly natural dopant that modifies the phytochemical properties of PANI nanocomposite thin films, enabling their optimization for enhanced light-harvesting applications in dye-sensitized solar cells and photocatalysis.