A comparative study of novel synthesized sulfamide compounds: Electrochemical, morphological, XPS, and theoretical investigations on copper corrosion inhibition in 1.0 M HCl

Abstract

This study investigates the corrosion inhibition performance of N-phenyl sulfamide (NPS) and N-phenyl piperazine sulfamide (NPPS) for copper in a solution of 1.0 M hydrochloric acid (HCl) through a comprehensive combination of experimental and theoretical approaches. Electrochemical methods (polarization measurements and electrochemical impedance spectroscopy (EIS)), characterization techniques (FTIR, ATR, SEM and XPS investigations), and theoretical calculations are employed to analyze the inhibitive properties and provide insights on how the inhibitors and copper surface interact. Results from polarization and EIS analyses reveal that NPS and NPPS, both at a concentration of 400 mg/L, deliver substantial corrosion inhibition, achieving rates of 92.33 % and 98.70 % for polarization, and 93.60 % and 96.51 % for EIS, respectively, which gives NPPS an advantage over the other inhibitor with high inhibitor efficiency. SEM and XPS investigations confirm the adsorption of these inhibitors to the copper surface, resulting in a notably smoother and more uniform appearance with minimal damage, especially for NPPS. Theoretical calculations employing the DFT-B3LYP method provide valuable insights into the molecular properties of NPS and NPPS. These simulations support the outcomes of the tests and give insight into how NPPS inhibitor act as stronger inhibitor compared with NPS inhibitor. Overall, this study enhances our understanding of corrosion protection mechanisms and offers crucial information in order to establish robust copper corrosion inhibitors for acidic conditions. The combination of theoretical and experimental approaches offers a thorough framework for investigating corrosion inhibition and opens the door for the creation of sophisticated and effective inhibitors to protect copper from corrosive attacks.