Alahiane Mustapha, Oukhrib Rachid, Albrimi Youssef Ait, Oualid Hicham Abou, Bourzi Hassan, Akbour Rachid Ait, Assabbane Ali, Nahlé Ayssar, Hamdani Mohamed
Ibn Zohr University, Science Faculty, Chemical Department Agadir Morocco.
Applied Chemistry-Physics Team, Faculty of Sciences, University of Ibn Zohr Agadir Morocco.
RSC Adv. 2020 Nov 12;10(67):41137-41153. doi: 10.1039/d0ra06742c. eCollection 2020 Nov 9.
The inhibition efficiency of benzoic acid (C1), -hydroxybenzoic acid (C2), and 3,4-dihydroxybenzoic acid (C3) towards enhancing the corrosion resistance of austenitic AISI 316 stainless steel (SS) has been evaluated in 0.5 M HCl using weight loss (WL), open circuit potential (OCP), potentiodynamic polarization method, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) analysis. The results obtained from the different experimental techniques were consistent and showed that the inhibition efficiency of these inhibitors increased with the increase in concentration in this order C3 > C2 > C1. In addition, the results of the weight loss measurements showed that these inhibitors followed the Villamil isotherm. Quantum chemical calculations and Monte Carlo simulations have also been used for further insight into the adsorption mechanism of the inhibitor molecules on Fe (110). The quantum chemical parameters have been calculated by density functional theory (DFT) at the B3LYP level of theory with 6-31G+(2d,p) and 6-31G++(2d,p) basis sets in gas and aqueous phase. Parameters such as the lowest unoccupied ( ) and highest occupied ( ) molecular orbital energies, energy gap (Δ), chemical hardness (), softness (), electronegativity (), electrophilicity (), and nucleophilicity () were calculated and showed the anti-corrosive properties of C1, C2 and C3. Moreover, theoretical vibrational spectra were calculated to exhibit the functional hydroxyl groups (OH) in the studied compounds. In agreement with the experimental data, the theoretical results showed that the order of inhibition efficiency was C3 > C2 > C1.
已使用失重法（WL）、开路电位（OCP）、动电位极化法、电化学阻抗谱（EIS）和扫描电子显微镜（SEM）分析，评估了苯甲酸（C1）、对羟基苯甲酸（C2）和3,4 - 二羟基苯甲酸（C3）对提高奥氏体AISI 316不锈钢（SS）在0.5 M HCl中的耐腐蚀性的抑制效率。从不同实验技术获得的结果是一致的，表明这些缓蚀剂的抑制效率随浓度增加而提高，顺序为C3 > C2 > C1。此外，失重测量结果表明这些缓蚀剂符合Villamil等温线。量子化学计算和蒙特卡罗模拟也被用于进一步深入了解缓蚀剂分子在Fe(110)上的吸附机制。量子化学参数已通过密度泛函理论（DFT）在B3LYP理论水平下，使用6 - 31G+(2d,p)和6 - 31G++(2d,p)基组在气相和水相中进行计算。计算了诸如最低未占（ ）和最高占据（ ）分子轨道能量、能隙（Δ）、化学硬度（ ）、软度（ ）、电负性（ ）、亲电性（ ）和亲核性（ ）等参数，并显示了C1、C2和C3的抗腐蚀性能。此外，计算了理论振动光谱以展示所研究化合物中的官能羟基（OH）。与实验数据一致，理论结果表明抑制效率顺序为C3 > C2 > C1。
