Enhanced charge carrier dynamics, synergistic effects, and photocatalytic properties in heterostructured polyaniline/sodium-doped nickel oxide nanocomposites

The synergistic integration of polyaniline (PANI) with sodium-doped nickel oxide (NNO) in nanocomposites form presents a promising strategy for addressing environmental challenges posed by methylene blue (MB), a persistent cationic dye pollutant. PANI/NNO composites were synthesized via in-situ chemical oxidative polymerization. X-ray diffraction analysis revealed an average crystallite size of approximately 12 nm. Fouriertransform infrared spectroscopy, Energy-dispersive X-ray spectroscopy, Elemental mapping, and X-ray photoelectron spectroscopy confirmed the successful formation of the composites. Field Emission Scanning Electron Microscopy images showed nanofibrous structures for composites. The composites exhibited enhanced thermal stability, as demonstrated by thermal gravimetric analysis. Electrical measurements indicated improved charge transport due to enhanced interactions between the components. The incorporation of sodium-doped nickel oxide into the polyaniline matrix significantly reduced the band gap to about 3.1 eV, improving light absorption. Photoluminescence studies indicated reduced recombination rates of charge carriers. Under UV irradiation, the composites achieved 93.72 % methylene blue degradation, retaining over 90 % efficiency over four catalytic cycles, highlighting their photostability. BET analysis showed a surface area of 73.46 m2/g, a pore diameter of 9.21 nm, and a pore volume of 119.74 cm3 /g, confirming the composites' potential for catalytic applications.