Experimental and DFT studies of selenium decorated graphene oxide: Redox stability, cytotoxicity, and corrosion inhibition of AZ13 Mg alloy

Abstract

The enhancement of both the corrosion resistance of metal alloys by coatings and the electrochemical stability of new materials remains an on-going challenge. Selenium and graphene oxide (GO) functionalized materials showing significant corrosion inhibition and electrochemical stability have been prepared and characterised in this work. Also, we performed cytotoxicity studies of the graphene oxide selenium composite materials in human dermal fibroblasts. The material characterization was performed by XRD (X-ray diffraction) to find out crystallinity of graphene oxide and FESEM (field emission scanning electron microscopy) and TEM (transmission electron microscopy) were used to determine the microstructure of selenium functionalized graphene oxide. Thermal stability was studied using TGA (thermal gravimetric analysis) to find out the structural changes during thermal treatment. Also, the electrochemical studies were performed to estimate corrosion behavior of the selenium functionalized GO. The stability was studied by cyclic voltammetry (CV) technique. Theoretical studies were performed using the density functional theory (DFT) to clarify structural and electronic features of the Se-functionalized graphene oxide sheets, and their results supported the experimental results. The corrosion inhibition efficiency study showed that selenium decorated GO acts as a mixed-type corrosion inhibition barrier enhancing electrochemical stability of the alloys.