The present study demonstrates a method to manipulate the adsorption behavior of corrosion inhibitor molecules through structural modification leading to significant enhancement of the corrosion inhibition efficiency. A weak corrosion inhibitor molecule 4-amino 1,2,4 triazole (AT) was structurally modified to N-(4H-1,2,4-triazol-4-yl)octanamide (OAT) through the attachment of an octanoyl chain as the hydrophobic tail. Probing of the adsorption behavior of both AT and OAT on mild steel in 1 M HCl using gravimetric, polarization, and electrochemical impedance spectroscopy (EIS) techniques revealed a change of the adsorption mechanism from physisorption to chemisorption due to the structural modification and the corrosion inhibition efficiency improved from 65% (for 10 mM AT) to 99% (for 0.3 mM OAT). OAT exhibited a temperature-independent inhibition efficiency of more than 99 % in 30-60 °C range. X-ray photoelectron spectroscopy (XPS) study indicated chemisorption of OAT molecules on the steel surface through nitrogen atoms of the triazole ring, resulting in the formation of a self-assembled monolayer (SAM). Finally, the efficacy of the OAT SAM to protect mild steel from corrosion in HCl medium was demonstrated using scanning electrochemical microscopy (SECM) and scanning electron microscopy (SEM).

本研究表明了一种通过结构修饰来控制缓蚀剂分子的吸附行为的方法，从而显着提高了缓蚀效率。弱腐蚀抑制剂分子4-氨基1,2,4三唑（AT）通过以下结构连接到N-（4H-1,2,4-三唑-4-基）辛酰胺（OAT）：疏水的尾巴。用重量法，极化法和电化学阻抗谱（EIS）技术对AT和OAT在1 M HCl中的低碳钢上的吸附行为进行了研究，结果表明，由于结构改性和缓蚀作用，吸附机理从物理吸附转变为化学吸附。效率从65％（对于10 mM AT）提高到99％（对于0.3 mM OAT）。OAT在30-60°C的温度范围内显示出超过99％的与温度无关的抑制效率。X射线光电子能谱（XPS）研究表明OAT分子通过三唑环的氮原子化学吸附在钢表面，导致形成自组装单层（SAM）。最后，使用扫描电化学显微镜（SECM）和扫描电子显微镜（SEM）证明了OAT SAM保护低碳钢免受HCl介质腐蚀的功效。