Exploring the Effectiveness of Isatin–Schiff Base as an Environmentally Friendly Corrosion Inhibitor for Mild Steel in Hydrochloric Acid

Abstract

A recent study has shown that Schiff base OHMHI is an effective inhibitor of the corrosion of mild steel in acidic media. The study utilized weight loss measurements and electrochemical techniques, such as EIS and potentiodynamic polarization, to analyze the corrosion inhibition efficiency of OHMHI. The results of the study show that the presence of OHMHI in the corrosive environment significantly reduced the corrosion rate of mild steel and increased its corrosion resistance. The impedance spectra analysis indicated that OHMHI was adsorbed on the surface of mild steel, providing a protective layer. The potentiodynamic polarization study confirmed the protective role of OHMHI by showing an increase in the passive current density of the mild steel in the presence of OHMHI. The inhibitory efficiency of OHMHI was found to be 96.1%, indicating that it is an effective corrosion inhibitor for mild steel. The study also investigated the optimal conditions for the use of OHMHI as a corrosion inhibitor, with a concentration of 0.5 mM and a temperature of 303 K being chosen. The Langmuir adsorption isotherm concept was used to demonstrate the physical and chemical adsorption of OHMHI on the surface of mild steel. Morphological investigations of the uninhibited and inhibited surfaces of the mild steel specimen were examined using scanning electron microscopy (SEM) analysis. Furthermore, computational investigations using density functional theory (DFT) and experimental data were merged to explore the corrosion inhibition efficiency and mechanism of inhibition. Although the results are promising, further studies are needed to determine the long-term effects of OHMHI on mild steel corrosion and to evaluate its effectiveness under different environmental conditions. Overall, the study highlights the potential of OHMHI as an effective corrosion inhibitor for mild steel in acidic media.

Corrosion Inhibition of Mild Steel in HCl Solution Using MPO: Experimental and Theoretical Insights

“…These results suggest that the inhibitor might present a viable alternative to conventional corrosion inhibitors. The inhibitory effectiveness increased rapidly within the initial 10 hours of immersion, remained relatively stable during the subsequent 10-24 hours, and gradually declined beyond the 24-hour mark [52,53]. Extended immersion periods resulted in a higher concentration of inhibitor molecules forming a consistent coating that hindered the corrosion process.…”

A Review of Inorganic Corrosion Inhibitors: Types, Mechanisms, and Applications

“…Mixed inhibitors are substances that can act on both anodic and cathodic reactions, and they usually provide more effective protection against corrosion [24].…”

The Corrosion Inhibition of Montmorillonite Nanoclay for Steel in Acidic Solution

“…Mild steel is a type of carbon steel with a low amount of carbon (typically a wt% of 0.05% to 0.25%); also known as “low-carbon steel”. Corrosion is considered as the most challenging problem for steel, especially when in contact with acidic media [ 1 ]. Huge financial and ecological losses are incurred due to the corrosion of steel worldwide.…”

“…Hydrochloric acid (HCl) and sulfuric acid (H 2 SO 4 ) are the two most commonly used acidic solutions for cleaning industrial equipment [ 2 ]. Anti-corrosion materials (corrosion inhibitors) are usually used in the process, for the protection of metals [ 1 , 3 , 4 , 5 , 6 ]. However, these materials are harmful and expensive, due to their chemical nature.…”