Multidimensional insight into the corrosion mitigation of clonazepam drug molecule on mild steel in chloride environment: Empirical and computer simulation explorations

Abstract

In recent years, the use of drugs-based compounds to inhibit mild steel corrosion has grown significantly. Clonazepam stands out among other drug based compounds employed as potential corrosion inhibitors. This study investigates the experimental and computational properties of clonazepam drug molecule as mild steel corrosion inhibitor in chloride solution using weight loss, thermometric, electrochemical impedance spectroscopy, potentiodynamics polarization, surface imaging, Density Functional Theory, and molecular dynamic simulations. The findings demonstrate that as clonazepam drug concentration is increased, the inhibition efficiency increases, reaching a maximum of 90.1% for weight loss, 89.2% for thermometric investigations, 91.4% for electrochemical impedance spectroscopy, and 85.1% for (potentiodynamics polarization) techniques at 500 ppm. The clonazepam drug functions as a mixed-type corrosion inhibitor as demonstrated by the potentiodynamic polarization method. The clonazepam drug adsorption followed the Langmuir adsorption isotherm. The mild steel surface has a barrier layers covering it, as shown by the surface characterization studies via SEM and AFM. The highest occupied molecular orbital (EHOMO), the energy of the lowest unoccupied molecular orbital (ELUMO), the energy gap (ΔE), chemical hardness (η), softness (σ), dipole moment (μ) and electronegativity (Ɛ) were all evaluated for neutral and protonated forms respectively. The molecular dynamic simulations evidenced a near flat adsorption orientation on the Fe surface.