The effect of Tetracycline drug as a green corrosion inhibitor for carbon steel in HCl media

Abstract

Corrosion protection of metals, and alloys is a prime activity of technical, economic, environmental, and aesthetical significance. The use of inhibitors is oneof the best choice of combating metals, and alloys against detoriation against environmental impact. The toxicity of organic, and inorganic corrosion inhibitors to the environment has provoked the search for eco-friendly corrosion inhibitors like green corrosion inhibitors as other more environmental friendly corrosion inhibitors. This research demonstrates the anti-corrosion effect of Tetracycline drug on carbon steel alloy (ck45) in 1 M hydrochloric acid using electrochemical measurements (Tafel polarization and impedance spectroscopy (EIS) techniques). Also, the activation energy, the thermodynamic parameters and adsorption isotherm were derived from the electrochemical results. The highest inhibition yield for ck45 alloy in 1.0 M hydrochloric acid using 300 ppm of the drug is about 82% and 78% by polarization and EIS method, respectively. The potentiodynamic polarization measurement result shows that Tetracycline is a mixed-type inhibitor. The adsorption of drug molecules on the alloy surface obeying the Langmuir adsorption isotherm model and the ΔG°ads value calculated, suggested that the drug molecules adsorbed on the alloy surface via a physisorption mechanism. Also, optical microscopy and scanning electronic microscopy (SEM) studies, confirmed the formation of a protective film over the metal surface.