Canthium parviflorum leaf extract (CPLE) was utilized for corrosion prevention against mild steel (MS) in 0.5[Formula: see text]mol[Formula: see text]L[Formula: see text] H2SO4 test medium. Standard corrosion measurement techniques (gravimetric and electrochemical) were employed for this purpose. Gravimetric tests clearly confirmed that the prepared CPLE efficiently performs as corrosion inhibitor. Potentiodynamic polarization measurements (PPM) and electrochemical impedance spectroscopy (EIS) measurements were performed in order to analyze the charge transfer process of CPLE. Polarization curves indicate that CPLE acts through mixed mode inhibition. Impedance study reveals that the CPLE additives enhances the charge transfer resistance values and conversely decreases values of double layer capacitance. Scanning electron microscopy (SEM), Ultraviolet-Visible (UV-Vis) spectroscopy analysis and Fourier-Transform Infrared spectroscopy (FTIR) were done to confirm the Fe-CPLE complex formation on MS. The effect of temperature reveals that the inhibition efficiency increases with decrease in temperature and increase in concentration of CPLE (maximum of 4[Formula: see text]mg[Formula: see text]L[Formula: see text]). The adsorption of CPLE shows that it obeys Langmuir’s isotherm model with free energy of adsorption, [Formula: see text][Formula: see text]kJ mol[Formula: see text]. A suitable adsorption model is also proposed.

中文翻译：

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小红花作为 0.5 M H2SO4 介质中低碳钢腐蚀的生物抑制剂的良性方法

Canthium parviflorum 叶提取物 (CPLE) 用于对低碳钢 (MS) 进行 0.5[公式：见正文]mol[公式：见正文]L[公式：见正文] H2所以4测试介质。为此目的采用了标准腐蚀测量技术（重量法和电化学法）。重量测试清楚地证实了制备的 CPLE 作为缓蚀剂有效地发挥了作用。进行动电位极化测量 (PPM) 和电化学阻抗谱 (EIS) 测量以分析 CPLE 的电荷转移过程。极化曲线表明 CPLE 通过混合模式抑制起作用。阻抗研究表明，CPLE 添加剂提高了电荷转移电阻值，相反降低了双层电容值。进行扫描电子显微镜 (SEM)、紫外-可见 (UV-Vis) 光谱分析和傅里叶变换红外光谱 (FTIR) 以确认在 MS 上形成 Fe-CPLE 复合物。温度的影响表明，抑制效率随着温度的降低和CPLE浓度的增加而增加（最大值为4[公式：见正文]mg[公式：见正文]L[公式：见正文]）。CPLE的吸附表明它服从Langmuir等温线模型，吸附自由能为[公式：见正文][公式：见正文]kJ mol[公式：见正文]。还提出了一种合适的吸附模型。