The corrosion inhibition performance of novel synthesized thiosemicarbazide derivative namely, 2-isonicotinoyl-N-phenylhydrazinecarbothioamide (IPC) on the mild steel coupon surface in 1M hydrochloric acid solution is investigated by weight loss measurements. The adsorption parameters of the IPC on the mild steel coupon surface have been evaluated and the surface morphology of the tested mild steel is studied by scanning electron microscope (SEM) technique. The results of this study demonstrate a significant inhibitor (IPC) for mild steel and showed the highest inhibitive efficiency of 96.3% at 5mM as optimum studied inhibitor concentration. The adsorption of IPC molecules on a mild steel coupon surface is obeyed completely by the model of Langmuir adsorption isotherms. SEM has been applied to analyse the layer of IPC molecules which formed on a mild steel coupon surface as a protective layer. The inhibition efficiency (IE) of IPC from weight loss techniques and SEM analysis was harmonic with each other. The Density Functional Theory (DFT) computations have been applied to evaluate the adsorption sites of the IPC molecules and the quantum chemical calculations correlation of IPC molecules with methodological results are discussed. The energy of the highest occupied molecular orbital (EHOMO) shows a significant tendency of the IPC molecules to donate pairs of electrons to the iron atoms on the surface of mild steel. The energy of the lowest unoccupied molecular orbital (ELUMO) for IPS molecules reveals a high tendency to accept electrons from iron atoms on the surface of mild steel.

中文翻译：

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2-异烟酰-N-苯肼甲硫胺在低碳钢盐酸溶液中的防腐性能：来自实验测量和量子化学计算的见解

新型合成的氨基硫脲衍生物即2-异烟酰-N-苯肼硫代氨基硫脲(IPC)在低碳钢试样表面的缓蚀性能1M盐酸溶液通过重量损失测量进行研究。评估了IPC在低碳钢试样表面的吸附参数，并通过扫描电子显微镜（SEM）技术研究了测试低碳钢的表面形貌。本研究的结果证明了一种显着的低碳钢抑制剂 (IPC)，并在 5 ℃时显示出 96.3% 的最高抑制效率mM 作为最佳研究抑制剂浓度。IPC分子在低碳钢试样表面的吸附完全符合朗缪尔吸附等温线模型。SEM 已被用于分析在低碳钢试样表面形成的 IPC 分子层作为保护层。来自失重技术和 SEM 分析的 IPC 的抑制效率 (IE) 相互协调。密度泛函理论 (DFT) 计算已应用于评估 IPC 分子的吸附位点，并讨论了 IPC 分子的量子化学计算与方法学结果的相关性。最高占据分子轨道 (EHOMO) 的能量显示出 IPC 分子向低碳钢表面的铁原子提供电子对的显着趋势。