Two schiff base as corrosion inhibitors for N80 in 1.0 M HCl: Experimental and theoretical studies

• Published in: Journal of the Indian Chemical Society 2024-11, Vol.101 (11), p.101316, Article 101316
• Main Authors: Fan, Lin, Wang, Pengjie, Song, Yuhao, Ansari, Kashif Rahmani, Li, Hao, Singh, Ambrish, Kong, Xiangwei, Lin, Yuanhua, Talha, Mohd
• Format: Article
• Language: English
• Subjects: DFT; Electrochemistry; Schiff base; Surface analysis; Weight loss experiment
• ISSN: 0019-4522
• DOI: 10.1016/j.jics.2024.101316

Two Schiff base inhibitor were synthesized and the structures of RX-1 and RX-2 were confirmed through infrared (IR) and nuclear magnetic resonance spectroscopy (NMR). The corrosion inhibition properties of the two Schiff base inhibitor on N80 steel in 1.0 M HCl were investigated. The results demonstrate that the corrosion inhibition efficiencies of RX-1 and RX-2 at 200 mg/L were 91.15 %, and 91.09 % by weight loss. The results of Electrochemical impedance spectroscopy (EIS) show that RX-1 and RX-2 form adsorption films on the surface of N80 steel to alleviate the corrosion. Tafel polarization curve (TAFEL) results showed that RX-1 and RX-2 reduced the dissolution of N80 by inhibiting both cathode and anode reactions. Scanning electron microscope (SEM), Energy Dispersive Spectrometer (EDS), X-ray photoelectron spectroscopy (XPS) confirmed the effective adsorption of RX-1 and RX-2 on the surface of N80 steel, thereby preventing direct contact between the corrosive medium and the metal. Density functional theory (DFT) Fukui and molecular dynamics simulation (MD) have proved that there are multiple adsorption sites in 1 M HCl at the molecular level, which can be stably adsorbed on the metal surface. Mean Squared Displacement (MSD) has proved that the protective film formed by RX-1 and RX-2 can slow down the corrosion of N80 steel by hindering the diffusion rate of corrosive ions. [Display omitted] •Two kinds of Schiff base corrosion inhibitors were synthesized successfully, and their structures were verified by FITR and NMR.•Weight loss and electrochemical studies show that corrosion inhibitors can effectively slow down the corrosion of N80 steel.•XPS + EDS proved that the corrosion inhibitors can adsorb on the surface of N80 steel.•Adding CC double bond to the structure can further improve the corrosion inhibition performance, and provide a certain reference for the development of corrosion inhibitors.•DFT + MD further validated the corrosion inhibition mechanism.