1,10-Phenanthroline (PHN) is a nitrogen-containing heterocyclic organic compound that is widely used in a variety of applications, including chemosensors, biological studies, and pharmaceuticals, which promotes its use as an organic inhibitor to reduce corrosion of steel in acidic solution. In this regard, the inhibition ability of PHN was examined for carbon steel (C48) in a 1.0 M HCl environment by performing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), mass loss, and thermometric/kinetic. Additionally, scanning electron microscopy (SEM) was used to examine the surface morphology of C48 immersed in 1.0 M HCl protected with our inhibitor. According to the PDP tests, increasing the PHN concentration resulted in an improvement in corrosion inhibition efficiency. Besides, the maximum corrosion inhibition efficiency is about 90% at 328 K. Furthermore, the PDP assessments demonstrated that PHN functions as a mixed-type inhibitor. The adsorption analysis reveals that our title molecule mechanism is due to physical–chemical adsorption, as predicted by the Frumkin, Temkin, Freundlich, and Langmuir isotherms. The SEM technique exhibited that the corrosion barrier occurs due to the adsorption of the PHN compound through the metal/1.0 M HCl interface. In addition, the computational investigations based on a quantum calculation using density functional theory (DFT), reactivity (QTAIM, ELF, and LOL), and molecular-scale by Monte Carlo (MC) simulations confirmed the experimental results by providing further insight into the mode of adsorption of PHN on the metal surface, thus forming a protective film against corrosion on the C48 surface.

1,10-菲咯啉 (PHN) 是一种含氮杂环有机化合物，广泛用于各种应用，包括化学传感器、生物研究和制药，这促进了它作为有机抑制剂的使用，以减少酸性条件下钢的腐蚀解决方案。在这方面，通过执行电化学阻抗谱 (EIS)、动电位极化 (PDP)、质量损失和测温/动力学，在 1.0 M HCl 环境中检查了 PHN 对碳钢 (C48) 的抑制能力。此外，扫描电子显微镜 (SEM) 用于检查浸入 1.0 M HCl 中并受我们的抑制剂保护的 C48 的表面形态。根据 PDP 测试，增加 PHN 浓度导致缓蚀效率提高。除了，在 328 K 时，最大腐蚀抑制效率约为 90%。此外，PDP 评估表明 PHN 作为混合型抑制剂发挥作用。吸附分析表明，我们的标题分子机制是由于物理化学吸附，正如 Frumkin、Temkin、Freundlich 和 Langmuir 等温线所预测的那样。SEM 技术表明，腐蚀屏障是由于 PHN 化合物通过金属/1.0 M HCl 界面的吸附而产生的。此外，基于使用密度泛函理论 (DFT)、反应性（QTAIM、ELF 和 LOL）和蒙特卡罗 (MC) 模拟的分子尺度的量子计算的计算研究通过提供对PHN在金属表面的吸附方式，