Multifunctional Polyaniline–Silver Nanocomposites for Dye Removal, Corrosion Protection, and Antioxidant Activity

ABSTRACT

Multifunctional polyaniline–silver (Ag) nanocomposites were explored as a sustainable multifunctional material for environmental remediation and material protection applications. The nanocomposites achieved an efficient removal of fluorescein dye (89.6% ± 1.3%) under the selected experimental conditions of neutral pH, an initial dye concentration of 40 ppm, and an NC dose of 40 mg within 180 min at 60°C. The adsorption behavior was well explained by pseudo‐second‐order kinetics ( R ² = 0.9993) and Langmuir isotherm, exhibiting a maximum adsorption capacity of 52.8 mg g ^{− 1} . Anticorrosive performance studies on mild steel in 0.5 M HCl demonstrated superior protection by PANI–Ag nanocomposites in comparison with the garlic extract, with inhibition efficiencies of 85.04% and 82.2% from potentiodynamic polarization analysis and 82.1% and 62.0% from weight‐loss measurements, respectively. EIS results confirmed increased charge‐transfer resistance and the development of a protective film on the steel surface. Antioxidant evaluation using DPPH and ABTS assays revealed strong radical‐scavenging activity, achieving 87.91% ± 1.06% and 89.87% ± 1.32%, respectively, in methanol at a dose of 40 mg. These results highlight the ability of PANI–Ag nanocomposites to integrate dye remediation, corrosion protection and antioxidant functionality within a single multifunctional nanocomposite system, contributing to sustainable development goals (SDGs) 6, 9, and 12.