Fabrication of a Highly Tunable Graphene Oxide Composite through Layer-by-Layer Assembly of Highly Crystalline Polyaniline Nanofibers and Green Corrosion Inhibitors: Complementary Experimental and First-Principles Quantum-Mechanics Modeling Approaches

Three-dimensional graphene oxide (GO) nanosheets were utilized as a unique versatile platform for the fabrication of an effective anticorrosion system through a layer-by-layer (L-b-L) assembly technique. In this way, the highly ordered crystalline polyaniline (Pani) nanofibers and green corrosion inhibitors (GIs) were synthesized. Sustainable corrosion inhibitors were obtained from the extract of Urtica Dioica leaves. The GO-Pani-GI nanosheets were characterized by Fourier transform infrared spectroscopy, high resolution transmission electron microscopy, field-emission scanning electron microscopy, UV visible spectroscopy, and thermal gravimetric analysis. In addition, the adsorption features of Pani onto GO sheets and its binding propensity against GIs were assessed by applying first-principles quantum-mechanics (QM) modeling approaches. The anticorrosion properties of the GO-Pani-GI were then examined using electrochemical impedance spectroscopy and polarization test. The results achieved from QM modeling studies demonstrated that the Pani strongly anchored to GO surfaces via physisorption mechanism. Computations further declared that all GIs interacted with Pani through intermolecular H-bonds. Moreover, the experimental investigations revealed the superior anticorrosion performance of multilayered graphene nanocomposites.