The effect of sunflower seed shell extract (Helianthus annus) as an organic inhibitor on carbon steel in 1 M HCl

Currently, the increasing demand for environmentally friendly corrosion inhibitors. Sustainable organic inhibitor innovations can be an alternative in the industrial world that still uses hazardous chemical inhibitors. Carbon Steel is a material that is often used in the oil and gas industry. This type of steel is resistant to significant corrosion, so an effective solution is needed to minimise material degradation. This study investigates the potential of sunflower (Helianthus annus) seed shell extract, SSSE. as a sustainable, environmentally friendly corrosion inhibitor for steel in concentrated hydrochloric acid (1 M HCl), where these conditions are representative of an industrially hazardous environment. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation (PDP) methods were used in this study. With these two approaches, SSSE showed a high inhibition efficiency of 99.56 % at a concentration of 400 ppm, effectively reducing both anodic and cathodic corrosion reactions. Scanning electron microscopy (SEM) showed the formed protective layer on the steel surface, significantly reducing corrosion. These findings highlight SSSE as a feasible and environmentally friendly alternative to conventional inhibitors, showing great potential applications in various acidic environments.