The Persian Liquorice was introduced as a sustainable corrosion inhibitor with excellent inhibition action for mild steel in sodium chloride solution. Persian Liquorice is a root of Glycyrrhiza glabra including many active compounds like Glycyrrhizin (GL), 18β- Glycyrrhetinic acid (GA), Liquritigenin (LTG), Licochalcone A (LCA), Licochalcone E (LCE), and Glabridin (GLD). The Fourier transform infrared (FT-IR) spectroscopy was utilized to track various active components exist in the Persian Liquorice extract. Electrochemical impedance spectroscopy, potentiodynamic polarization and electrochemical current noise measurements were conducted to investigate the corrosion inhibition role of various concentrations of Persian Liquorice extract toward mild steel corrosion in sodium chloride solutions. Surface analysis, molecular dynamics and quantum mechanics simulation methods were combined to get insights of inhibitor molecules adsorption on the mild steel surface. The electrochemical investigations revealed that in the presence of 600 ppm Persian Liquorice extract the maximum inhibition efficiency of 98.8% was obtained, which is connected to the build-up of a protecting layer over the mild steel surface, blocking the pathway of harsh ions diffusion. There is no report on use of any sustainable corrosion inhibitor for mild steel in chloride solution with this high level of inhibition power even after long immersion time (72 h). The formation of protecting layer on the mild steel surface was proved by scanning electron microscope and atomic force microscope results. The results derived from MD simulations and QM calculations revealed the adsorption of Persian Liquorice components on the steel substrate via donor-acceptor interactions.

的波斯甘草被引入作为具有用于在氯化钠溶液软钢优良抑制作用可持续的腐蚀抑制剂。波斯甘草是根光果甘草包括像甘草甜素（GL）许多活性化合物，18β-甘草次酸（GA），甘草素（LTG），甘草查耳酮A（LCA），甘草查耳酮E（LCE），光甘草定和（GLD）。傅里叶变换红外（FT-IR）光谱用于跟踪波斯甘草提取物中存在的各种活性成分。进行了电化学阻抗谱，电势极化和电化学电流噪声测量，以研究不同浓度的三氯甲烷的腐蚀抑制作用。在氯化钠溶液中，波斯甘草提取物对轻度钢的腐蚀作用。结合表面分析，分子动力学和量子力学模拟方法，获得了抑制剂分子吸附在低碳钢表面上的见解。电化学研究表明，在600 ppm波斯甘草精存在下提取物的最大抑制效率为98.8％，这与在低碳钢表面上形成保护层有关，从而阻止了苛刻的离子扩散路径。没有关于在氯化物溶液中使用任何可持续的缓蚀剂，即使在长时间浸泡（72小时）后仍具有如此高的抑制能力的缓蚀剂。通过扫描电子显微镜和原子力显微镜结果证明了在低碳钢表面上形成保护层。MD模拟和QM计算得出的结果表明，波斯甘草成分通过供体-受体相互作用吸附在钢基底上。