The inhibitive action of 2-mercaptobenzothiazole on the porosity of corrosion film formed on aluminum and aluminum–titanium alloys in hydrochloric acid solution

Abstract

Abstract2-Mercaptobenzothiazole (2-MBT) in a solution of 0.5 M HCl is an effective corrosion inhibitor for aluminum and aluminum–titanium alloys. Tafel polarization and electrochemical impedance spectroscopy (EIS) were employed to assess this heterocyclic compound’s anticorrosive potential and complementary by scanning electron microscope (SEM) and calculating porosity percentage in the absence and presence of various inhibitor concentrations. Inhibition efficiency (IE%) was strongly related to concentration (10–6–10–3 M). Temperature’s effect on corrosion behavior was investigated. The data exhibited that the IE% decreases as the temperature increases. An increase in activation energy (Ea) with increasing the inhibitor concentration and the decrease in the IE% value of the mentioned compound with raising the temperature indicates that the inhibitor molecules are adsorbed physically on the surface. Thermodynamic activation parameters for Al and Al–Ti alloy dissolution in both 0.5 M HCl and the inhibited solution were calculated and discussed. According to Langmuir’s adsorption isotherm, the inhibitor molecules were adsorbed. The evaluated standard values of the enthalpy ($$\Delta {H}_{ads.}^{o})$$ Δ H a d s . o ) , entropy ($$\Delta {S}_{ads.}^{o})$$ Δ S a d s . o ) and free energy changes ($$\Delta {G}_{ads.}^{o})$$ Δ G a d s . o ) showed that $$\Delta {H}_{ads.}^{o}$$ Δ H a d s . o and $$\Delta {G}_{ads.}^{o}$$ Δ G a d s . o are negative, while $$\Delta {S}_{ads.}^{o}$$ Δ S a d s . o was positive. The formation of a protective layer adsorbed on the surfaces of the substrates was confirmed with the surface analysis (SEM). The porosity percentage is significantly reduced in the inhibitor presence and gradually decreased with increasing concentration. Furthermore, the density functional theory (DFT) and Monte Carlo (MC) simulations were employed to explain the variance in protecting the Al surface from corrosion. Interestingly, the theoretical findings align with their experimental counterparts. The planarity of 2-MBT and the presence of heteroatoms are the playmakers in the adsorption process.

Tracing the impact of CO2 on the electrochemical and charge–discharge behavior for Al–Mg alloy in KOH and LiOH electrolytes for battery applications

“…Additionally, the CPE has an exponent called “n” that is used to look at changes in the metal/solution interface. The near-unity values of n 59 , which show the predominant capacitive response as in the current investigation, are caused by the frequency dispersion created by an appropriately dispersed current on the surface of the electrode.…”

“…A category of characteristics related to both the surface and the electroactive components is referred to as CPE . Because of the dispersion of relaxation times brought on by inhomogeneities such as adsorption, diffusion, and surface roughness/porosity, the CPE is essential 59 . Additionally, the CPE has an exponent called “n” that is used to look at changes in the metal/solution interface.…”

Cerium and aluminum molybdates as inhibitors of the aluminum AA1050 corrosion process in aqueous NaCl solutions

“…It can be seen that there is a clear shift of the corrosion potential to more negative values, indicating that, although corrosion inhibition is under mixed control, the cathodic effect is more pronounced. [ 42 ] It can also be appreciated how the inhibition effect of the synthesized molybdates results in a significant decrease of the corrosion current density.…”

Recycling of Expired drug (levofloxacin hemihydrate) as a potential Eco-friendly Inhibitor for Copper in Synthetic Acid Rain Solution (SAR)

“…E corr value shifts of less than ±85 mV (El-Sayed et al, 2023a), were interpreted to indicate that the medication under study acts as a mixed-type inhibitor. To the same extent, the addition of LFH to the SAR solution alters the kinetics of both the anodic and cathodic processes as evidenced by variations in the Tafel slopes (Varvara et al, 2022).…”

“…The analogous circuit has two resistors: R 1 , solution resistance (R s ), and R 2 , the corrosion process' charge transfer resistance at Cu/solution interface, as well, W 2 , the Warburg impedance caused by the diffusion of the corrosive reactant of the appropriate product species. In place of an ideal capacitance element, constant phase element (CPE) (Q 2 ) was developed to account for surface roughness and heterogeneities (El-Sayed et al, 2023a), and the following Equation describes the value for (CPE):…”