Inhibition efficiency of gold nanoparticles on corrosion of mild steel, stainless steel and aluminium in 1M HCl solution

Abstract In this study, the influence of gold nanoparticles (AuNPs) on corrosion behavior of mild steel, aluminium and stainless steel in 1.0 M HCl was investigated. The nanoparticles were previously characterized using FTIR, UV–Vis and TEM. Five concentrations of AuNPs solution (0 µg/ml, 5 µg/ml, 10 µg/ml, 15 µg/ml, 20 µg/ml) were added to 1M HCl. The corrosion rates of the metal samples and inhibition efficiency of the nanoparticles were analyzed using gravimetric (weight loss) and potentiodynamic polarization techniques. After 2000 h of exposure, gravimetric study showed that weight loss was reduced by ∼75% translating to ∼85% reduction in corrosion rate for the solution containing 20 µg/ml of AuNPs. The equivalent inhibition efficiency was 88%, 98% and 96% for aluminium, mild steel and stainless steel, respectively. Furthermore, potentiodynamic polarization results showed that the presence of AuNPs modified the mechanism of anodic dissolution by the formation of adsorption layer on the surface of the metal samples. These results indicated that AuNPs can be incorporated into existing inhibitors towards minimizing corrosion rate.