Recycling of expired ciprofloxacin in synthetic acid rain (SAR) solution as a green corrosion inhibitor for copper: a theoretical and experimental evaluation

Abstract

The antibiotic Ciprofloxacin (CIPRO) was investigated as a new inhibitor for copper corrosion in Synthetic Acid Rain Solution (SAR) utilizing Mass Loss (ML) as a chemical method, Potentiodynamic Polarization (PDP), and Electrochemical Impedance Spectroscopy (EIS) as electrochemical techniques. In the presence of 600 ppm of the antibiotic CIPRO, the protection percentage reached 90.1% according to the EIS technique. Thermodynamic adsorption and activation characteristics were evaluated and described. The CIPRO adsorption on the Cu surface in the SAR solution was physical adsorption and complied with the Langmuir isotherm. According to PDP curves, the studied medication was served as a mixed type of inhibitor. This medication prevented corrosion by adhering to the metallic surface, which was demonstrated by Atomic Force Microscopy (AFM), Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM–EDX), and Fourier-Transform Infrared Spectroscopy (FTIR). Results from the Density Functional Theory (DFT) and Monte Carlo simulations (MC) complement experimental results. The inhibition efficiencies obtained via different methods are consistent with each other. Graphical Abstract: [Figure not available: see fulltext.].