Designing a potent anti-corrosion system based on graphene oxide nanosheets non-covalently modified with cerium/benzimidazole for selective delivery of corrosion inhibitors on steel in NaCl media

Graphene oxide was utilized as a unique nano-platform for high capacity of adsorption/desorption of corrosion inhibitors in order to fabricate a controlled release system with targeted delivery of inhibitive compounds on the corrosion sites of metal. Therefore, in this study, the graphene oxide (GO) nanosheets surface was modified by combination of benzimidazole/cerium compounds. Field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy techniques were utilized for estimating the adsorbed inhibitors concentration on the GO sheets. In order to optimize the inhibitors concentration and adsorption sequence onto the GO surface, electrochemical impedance spectroscopy analysis was done. The results evidenced the excellent controlled release properties of benzimidazole and cerium ions from the GO surface in the corrosive media, leading to significant reduction of the corrosion current density and increment of the corrosion resistance. The GO sample modified by benzimidazole/cerium in 1:1 ratio (adsorption of benzimidazole and then cerium) revealed the highest inhibition efficiency (>72%). (C) 2019 Elsevier B.V. All rights reserved.