Electrochemical characterization of ZnO/Mt@Fe-TA nanocontainers tested as corrosion inhibitor for metallic structures in a 3.5% NaCl medium

This work presents the electrochemical behavior of ZnO/Mt@Fe-TA nanocontainers as corrosion inhibitors at 50, 100 and 200 ppm on a low-carbon steel in NaCl (3.5%). The nanocontainer was, composed of a ZnO core with a hierarchical structure and Mimosa tenuiflora (Mt) extract as a stored substance and encapsulated with an external layer of iron-tannic acid complex (Fe-TA). The characterization of the nanocontainers was performed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS). Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization Curves (PPC). The results showed that the concentration of 100 ppm presented the highest efficiency. Finally, it was found that the adsorption mechanism of the nanocontainers is physisorption, this was determined by the adjustment made with the Frumkin–Fowler–Guggenheim (FFG) adsorption isotherm. Graphical abstract