<i>Phyllanthus urinaria</i> extract as a potential anti-corrosion agent for steel reinforcement in simulated marine environments

Purpose Corrosion of steel in marine environments poses a significant economic and environmental challenge because of its detrimental effects on marine structures and equipment. Traditional chemical inhibitors that mitigate corrosion often introduce harmful substances into the environment. As a result, there is a growing interest in exploring eco-friendly alternatives, such as plant-derived inhibitors, to reduce the environmental impact of corrosion protection strategies. The purpose of this study is to investigate the effectiveness of Phyllanthus urinaria extract as a green anti-corrosion additive for rebar steel in marine conditions. Design/methodology/approach Phyllanthus urinaria extract was prepared in the ethanol solution with the assistance of a sonicator. The steel’s surface upon addition of the extract was characterized using SEM, EDX and FTIR analysis. The electrochemical corrosion characteristics, including potentiodynamic polarization and electrochemical impedance spectroscopy, were used to evaluate the inhibitory performance of the extract on steel under simulated marine conditions (3.5% NaCl solutions). Findings The results of this study showed that with Phyllanthus urinaria extract’s content of 0.02% in NaCl solution of 3.5%, the corrosion rate decreased to about 30% compared to the controlled sample. Measurements of the inhibitory mechanism analysis study for all solutions from 0 mg/L to 1.114 mg/L of polyphenol from Phyllanthus urinaria extract showed a significant reduction in rebar corrosion rate, especially with 0.2228 mg/L polyphenol. Reinforcement can increase corrosion inhibition by up to 30% compared to the control sample. Originality/value To the best of the authors’ knowledge, this is the first study of using Phyllanthus urinaria extract as green inhibitor for protection of steel from the corrosion in the simulated marine solution. The protective mechanism for steel using Phyllanthus urinaria extract was investigated using the FTIR, SEM, EDX and electrochemical analysis. The results indicated that the polyphenols in the extract showed inhibition that could minimize the corrosion of reinforcement in marine environments.