Corrosion inhibition of C-steel in acidic media from fruiting bodies of Melia azedarach L extract and a synergistic Ni2+ additive

Abstract

The inhibiting ability of the fruiting bodies of Melia azedarach Linn extract (FB-MAL) and its synergistic effect with nickel ions (Ni²⁺) on the corrosion of carbon (C)-steel in hydrochloric acid were investigated using gravimetric measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The FB-MAL inhibited C-steel corrosion in acidic media up to 76.5%. Combining the FB-MAL with Ni²⁺ enhanced the adsorption capability of FB-MAL, greatly and consequently increased its inhibitive effect. Potentiodynamic polarization studies revealed that FB-MAL and FB-MAL + 100 ppm Ni²⁺ behave as mixed-type inhibitors. The EIS spectra showed that the charge transfer controls the corrosion process. The studied system obeys the Langmuir adsorption isotherm. The kinetic parameters were computed and are discussed later in this paper. The formation of the protective film was confirmed using Fourier transform-infrared spectroscopy, UV-Visible spectroscopy and scanning electron microscopy.