Electrochemical and surface evaluation of the anti-corrosion properties of reduced graphene oxide

Abstract

Herein, reduced graphene oxide nanosheets (RGON) were electrochemically grown onto a carbon steel alloy from graphene oxide (GO). The produced RGON was characterized using FT-IR, Raman, XRD, SEM and TEM techniques. Then, the anti-corrosion performance of the RGON-deposited layers was evaluated by weight loss and electrochemical methods such as open circuit potential (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in NaCl 3.5%. Covering the surface with RGON led to a negative shift in the corrosion potential (E_corr) and a decrease in the slope of the cathodic (β_c) and anodic (β_a) reactions, in which both demonstrate that the RGON can hinder the corrosion reaction. Parameters affecting film formation and consequently anti-corrosion performance, such as applied voltage and deposition time, were optimized. After applying 12 V during 180 s, the formed RGON layer on carbon steel showed the lowest corrosion current density (J_corr) and corrosion rate (CR), and the highest charge transfer resistance (R_ct). Finally, the morphology of the uncovered surface and that covered by RGON after 72 h immersion in NaCl 3.5%, was studied using SEM and EDXA techniques. The observed results are presented and discussed here.