Abstract

In the present study, we evaluated the effect of corrosion inhibition of ethanol extracts from Endostemon tereticaulis and Hyptis spicigera plants on mild steel in 1M HCl solution, using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Also surface characterization techniques, namely scanning electron microscopy and X-ray energy dispersive spectroscopy (EDX), UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy were used. These plants extracts showed a good corrosion inhibitory efficiency. The inhibition efficiency increased with increasing of the concentration of the extracts. The potentiodynamic polarization studies showed that these extracts were mixed inhibitors, affecting both anodic and cathodic processes. Electrochemical impedance spectroscopy revealed that the corrosion phenomenon is controlled by the charge transfer process. The adsorption of organic molecules from these extracts onto the surface of mild steel followed the Langmuir isotherm. The study of the morphology of the steel surface before and after immersion showed the adsorption of the molecules of these extracts onto the surface of the steel. Analyses by UV-visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy confirmed the adsorption of these extracts by the formation of a protective film onto the steel surface.

中文翻译：

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使用 Endostemon tereticaulis (Pear.) M.Ashby 和 Hyptis spicigera Lam。植物提取物作为低碳钢在 1M HCl 中的腐蚀绿色抑制剂：电化学和表面形态研究

摘要

在本研究中，我们评估了来自Endostemon tereticaulis和Hyptis spicigera的乙醇提取物的腐蚀抑制效果使用动电位极化曲线和电化学阻抗谱 (EIS) 在 1M HCl 溶液中的低碳钢上进行植物研究。还使用了表面表征技术，即扫描电子显微镜和 X 射线能量色散光谱 (EDX)、紫外-可见光谱、傅里叶变换红外光谱 (FTIR) 和拉曼光谱。这些植物提取物显示出良好的腐蚀抑制效率。抑制效率随着提取物浓度的增加而增加。动电位极化研究表明，这些提取物是混合抑制剂，影响阳极和阴极过程。电化学阻抗谱表明腐蚀现象是由电荷转移过程控制的。这些提取物中的有机分子吸附到低碳钢表面上遵循朗缪尔等温线。浸泡前后钢表面形貌的研究表明，这些提取物的分子吸附在钢表面上。紫外-可见光谱、傅里叶变换红外光谱 (FTIR) 和拉曼光谱分析证实了这些提取物通过在钢表面形成保护膜而吸附。