Exploring cinnamon extract’s potential as a green corrosion inhibitor for X65 carbon steel in sulfuric acid: a comprehensive investigation

Abstract

The effectiveness of cinnamon extract as an environmentally friendly corrosion inhibitor for X65 carbon steel (X65CSt) in a 1 mol/L H2SO4 solution was examined using electrochemical, chemical, and computational techniques. This inhibitor has many advantages, it is safe, environmentally friendly, harmless to human health, and economically feasible. The anticorrosion efficacy rises with rising the concentration of the cinnamon extract and reducing temperature and reaches 95.83% at 450 mg l−1 of cinnamon extract using potentiodynamic polarization. All the investigated methods confirm the anticorrosion ability of cinnamon extract as indicated by the reduced the corrosion current density values and mass loss as well as the greater charge transfer resistance. In addition, the values of the pitting potentials were also transformed in a more noble direction implying the resistance of pitting attack. The polarization technique categorized the cinnamon extract as a mixed inhibitor. The mechanism of inhibition was demonstrated in terms of adsorption of the main components of cinnamon extract onto the surface of X65CSt. of the adsorption of the main components of the cinnamon extract on the surface of the X65CSt and this adsorption is of combined type between both physical and chemical modes, as determined by the computed values of free energy of adsorption, which range between −46.96 and −37.42 kJ. mol−1. The adsorption is exposed to Langmuir isotherm. The four components of cinnamon extract were investigated through density functional theory, Monte Carlo, and Molecular dynamic simulation. The quantum parameters and the adsorption of these components on the Fe(110) reveals that cinnamaldehyde and cinnamic acid inhibitors are more effective as corrosion inhibitors.