Samarium functionalized few-layer nano graphene oxide redox behavior, cytotoxicity and corrosion inhibition on Mg AZ31 alloy in 3.5% NaCl environment

The development of novel high-performance corrosion protection coatings for Mg alloys still represents a great research challenge. Strongly motivated by the lack of studies of Sm-containing materials as corrosion protectors/inhibitors and by successful studies of graphene oxide (GO)-based composites for this purpose, we developed the novel Sm-modified GO composite as a corrosion inhibition barrier layer on the Mg alloy AZ31 in 3.5% NaCl environment. Sm-functionalized graphene oxide materials showed excellent anticorrosion resistance and redox stabilities. The Fourier-transform infrared (FTIR) and Raman studies confirmed the presence of the GO functional groups. The field emission scanning electron microscopy (FESEM) and tunneling electron microscopy (TEM) studies suggested the presence of the few-layer nanographene oxide sheets. The redox stability studies showed the Sm-GO composite material to be stable at high voltage and to control anodic and cathode reactions at the alloy surface. The density functional theory (DFT) study supported the experimental results, suggesting high potential reactivity of the Sm-functionalized GO composite materials towards corrosive agents. Moreover, we determined the concentrations associated with the low risk of its cytotoxicity.