This study investigates Congo Red Textile Dye (CRD) as a corrosion inhibitor for aluminum in a 1.0 mol/L hydrochloric acid solution. Utilizing a comprehensive suite of analytical techniques, including gravimetric analysis, scanning electron microscopy (SEM), ultraviolet–visible spectrophotometry (UV–Vis), Electrochemical Impedance Spectroscopy (EIS), and Potentiodynamic Polarization curves (PDP), we assessed CRD’s adsorption mechanism and its corrosion inhibition effectiveness. Significant corrosion mitigation was observed, with the efficiency of inhibition EI (%) increasing alongside CRD concentration, achieving a maximum efficiency of 87.5 %. This enhancement in EI (%) decreases with rising temperatures, assessed across a range from 298 to 323 K. Response surface methodology (RSM) and central composite design (CCD) were employed for accurate corrosion rates (V) and EI (%) prediction. Additionally, theoretical analysis was performed using global and local reactivity descriptors along with molecular dynamics (MD) simulations. Theoretical results confirmed the widespread presence of nucleophilic and electrophilic sites, along with a strong affinity for the Al surface, suggesting CRD’s potential for enhancing corrosion resistance. This study proposes a potential pathway for the valorization of Congo Red dye, utilizing concentrations within non-toxic thresholds, thereby aligning with environmental safety and industrial application considerations.

中文翻译：

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探索刚果红染料作为 HCl 溶液中铝腐蚀抑制剂的功效：RSM 建模和理论模拟的跨学科研究

本研究研究刚果红纺织染料 (CRD) 作为铝在 1.0 mol/L 盐酸溶液中的缓蚀剂。利用一整套分析技术，包括重量分析、扫描电子显微镜 (SEM)、紫外可见分光光度法 (UV-Vis)、电化学阻抗谱 (EIS) 和动电位极化曲线 (PDP)，我们评估了 CRD 的吸附机制并其缓蚀效果。观察到腐蚀显着减轻，抑制效率 EI (%) 随着 CRD 浓度的增加而增加，最高效率达到 87.5%。 EI (%) 的增强随着温度的升高而降低，在 298 至 323 K 的范围内进行评估。采用响应面方法 (RSM) 和中心复合材料设计 (CCD) 来准确预测腐蚀速率 (V) 和 EI (%) 。此外，还使用全局和局部反应性描述符以及分子动力学（MD）模拟进行了理论分析。理论结果证实了亲核和亲电子位点的广泛存在，以及与铝表面的强亲和力，表明 CRD 具有增强耐腐蚀性的潜力。这项研究提出了刚果红染料增值的潜在途径，利用无毒阈值内的浓度，从而符合环境安全和工业应用的考虑。