Corrosion inhibition of mild steel in acidic solution by leaves and stem extract of Acacia nilotica

Plant extracts have become vital as an eco-friendly and renewable resource for a wide range of corrosion inhibition applications. In this work, the inhibitive action of water extracts of Vachellia nilotica (VN) leaves and gum arabic (GA) stem of the Acacia nilotica on the corrosion of mild steel was studied using electrochemical measurements. The plant extracts were characterized by Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy, energy dispersive X-ray spectroscopy and also gas chromatography-mass spectrometry analysis to detect the majority of organic natural compounds in the extract. The adsorption of the inhibitor on mild steel surface was found to follow the Langmuir adsorption isotherm. Surface characterization by FTIR and SEM confirmed the formation of a protective layer on the mild steel surface. The efficiency obtained from the impedance data was around 89% for VN leaves and 86% for GA stem at 25°C. From these results, we conclude that VN leaves and GA stem show promising results as an eco-friendly and mild steel corrosion inhibitors.