A sustainable phytochemical strategy for acidic iron corrosion control: Electrochemical insights into Platanus orientalis fruit aqueous extract

The present study investigates, for the first time, the corrosion inhibition potential of an aqueous extract obtained from the fruit of Platanus orientalis, commonly known as the plane tree belonging to the Platanaceae family and collected from the Niğde Ömer Halisdemir University central campus, as a sustainable bio-based inhibitor for iron in 1 M hydrochloric acid (HCl) solution. The inhibition performance of the plant-derived extract was investigated in 1 M HCl solution at several concentrations. After an hour of immersion, electrochemical tests such as potentiodynamic polarisation analyses, linear polarisation resistance (LPR), and electrochemical impedance spectroscopy (EIS) were performed to evaluate the protective behaviour of the inhibitor on the iron surface. According to the electrochemical data, the extract greatly enhanced iron’s resistance to corrosion in the acidic medium, and the inhibition efficacy increased with the inhibitor concentration. Surface morphology examinations performed using field emission scanning electron microscopy (FESEM) further supported the electrochemical findings. Compared with the severely damaged surface observed in the uninhibited acidic solution, the samples exposed to the Platanus orientalis fruit extract displayed a considerably smoother and less deteriorated morphology. The formation of a protective adsorbed layer on the iron surface is suggested to be responsible for the observed corrosion inhibition. These findings suggest that the aqueous extract of Platanus orientalis fruit can be considered a promising green corrosion bio-inhibitor for iron in HCl environments, offering a plant-derived and environmentally responsible strategy for acidic corrosion control.