Inhibition of copper corrosion by the essential oil of Allium sativum in 0.5M H2SO4 solutions

Abstract

Materials in general and copper in particular, have a wide variety of industrial applications. However, they can easily corrode in aggressive environments. The anticorrosive action of copper by the essential oil of Allium sativum in a 0.5M H 2 SO 4 solutions has been studied using electrochemical techniques: electrochemical impedance spectroscopy and potentiodynamic polarization. The polarization curves indicate that the studied oil acts as a cathodic inhibitor retarding the cathodic reaction. An appropriate electrical equivalent circuit model was used to calculate the electrochemical impedance parameters. The results obtained showed that the inhibition efficiency depends on the inhibitor concentration and the temperature. This efficiency reached 97% at a concentration of 1.0 g/L. Some thermodynamic parameters for activation process and metal dissolution such as activation energy (Ea) activation entropy (ΔSa) and the activation enthalpy (ΔHa) were also calculated and discussed.

Study of the Electrochemical Behavior of Concrete‐Coated Steel in 1 M Sulfuric Acid Using an Extract of Diplotaxis simplex L.

“…Where Q denotes the CPE coefficient, n the CPE exponent ( 0<n<1 ), ω the angular frequency ( ω=2πf , f is the AC frequency), and j =−11/2. When n =1, the CPE is thought to behave like an ideal double‐layer capacitance ( C dl ) [38] . C dl values can be calculated as per Equation 2: [39] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {C}_{dl}=Q{\left({\omega }_{max}\right)}^{n-1}\hfill\cr}}$$$ …”

“…The DS extract was subjected to analysis using an analytical HPLC-DAD system (Thermo Fisher Scientific, USA) equipped with a C18 column (25 cm×4.6 mm×5 μm), similar to the method employed by Saoudi et al in 2021. [38] The elution process was conducted at a flow rate of 1.2 mL/min, employing a mobile phase comprising acidified water (pH = 2.65) (solvent A) and a mixture of water/ acetonitrile (20 : 80 v/v, pH = 2.65) (solvent B). The gradient program followed these steps: 35 minutes from 0.1 % to 30 % B, 5 minutes from 30 % to 50 % B, 5 minutes from 50 % to 99.9 % B, and finally, 15 minutes from 99.9 % back to 0.1 % B.…”

“…When n = 1, the CPE is thought to behave like an ideal double-layer capacitance (C dl ). [38] C dl values can be calculated as per Equation 2: [39]…”

Sustainable and Green Corrosion Inhibition of Mild Steel: Insights from Electrochemical and Computational Approaches

“…Their nontoxic and biodegradable nature makes them a promising candidate for use as corrosion inhibitors in harsh environments, including hydrochloric acid. EOs have effectively protected metals like copper and aluminum from corrosion. − …”