Anti-corrosive properties of two new green heterocyclic azole derivatives on C38 steel in 1 M (HCl) medium, experimental and theoretical study

In 1.0 M HCl media, two newly component namely (1-Allyl-6-nitro-1H-indazole (1a) & 1-Ethyl-5-nitro-1H-benz-imidazole-2-thiol (2b)) were used to inhibit corrosion of C38-steel. The activity inhibitor (IE%) of 1a & 2b was investigated using electrochemical, i.e., potentiodynamic polarization (PDP), electrochemical impedance spec-troscopy (EIS) & weight loss.The experimental results revealed that 1a & 2b successfully inhibited the C38-steel corrosion in C = 1.0 M// HCl solution. The IE(%) values produced by the three approaches were nearly identical, with the maximum value (97.5 %) obtained at T = 298 k of 2b.The high temperatures showed a negative effect on the corrosion inhibition efficiency of the tested inhibitor. Polarization methods revealed that the inhibitor behavior is of a mixed nature. The adsorption isotherm was also studied, and it was observed that 1a & 2b adsorbs on the C38-steel surface in agreement with the Langmuir isotherm, which indicated that both molecules adsorb on the metal's surface, producing a protective layer that inhibits corrosion. The computational results demonstrate that the inhibitor formed a protective barrier against acid attack, preventing carbon steel from corrosion; these findings backed with the experimental findings. In addition, the regioselectivities experimentally observed were interpreted by Parr functions.

Automated summary

In 1.0 M HCl media, two newly component, 1-Allyl-6-nitro-1H-indazole (1a) and 1-Ethyl-5-nitro-1H-benz-imidazole-2-thiol (2b), were used as inhibitors to prevent corrosion of C38-steel. The electrochemical methods, including potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and weight loss, were used to investigate the inhibition efficiency (IE%) of 1a and 2b. The results showed that both 1a and 2b effectively inhibited the corrosion of C38-steel in 1.0 M HCl solution, with the highest IE% (97.5%) achieved by 2b at a temperature of 298 K. The inhibitor behavior was found to be a mixed nature, and the adsorption isotherm study indicated that both 1a and 2b adsorb on the metal surface, forming a protective layer against corrosion.