Chitosan biomolecules-modified graphene oxide nano-layers decorated by mesoporous ZIF-9 nanocrystals for the construction of a smart/pH-triggered anti-corrosion coating system

The present research has focused on introducing a novel carbon nano-filler modified by stable nano-crystals based on Co-based MOF (called ZIF-9). For improving the GO dispersion, the graphene layers were modified with chitosan (CS-rGO) and then decorated with MOF particles. The fabricated hybrid particles' structures were probed by detailed spectroscopic techniques (i.e., XRD, UV-Vis, Raman, and FT-IR) and the morphology was observed by FE-SEM. The zeta potential and UV-Vis/ICP achievements displayed the pH sensitivity of the constructed ZIF-9@CS-rGOs structure. The solution phase electrochemical explorations displayed the ZIF-9@CS-rGO nanoparticles' effectiveness in anodic reaction rate mitigation, providing corrosion resistance around 4100 Ω.cm 2 in the best condition (EIS), and the FE-SEM images have proved that a high compact film generation could result in the steel surface damage control in chloride media. The active protection ability of the ZIF-9@CS-rGO/EP scratched composite was explored by EIS approaches and the scratched line morphology was probed by aiding FE-SEM. Outcomes have displayed that the scratched composite resistance was raised to 89000 Ω.cm 2 after ZIF-9@CS-rGO inclusion and FE-SEM micrographs have displayed sufficient scratched line surface coverage. Also, the intact ZIF-9@CS-rGO/EP composite coating resistance was improved to 26 MΩ.cm 2 , confirming the notable EP pathways blockage after introducing ZIF-9@Cs-rGO nano-filler.