Abstract
Corrosion remains a significant challenge across various industrial sectors, resulting in substantial economic losses, environmental hazards, and safety risks. Traditional corrosion inhibitors, though effective, often pose toxicity and environmental concerns, prompting the need for sustainable alternatives. The demand for eco-friendly and sustainable chemical species is increasing as industries seek to replace conventional toxic substances. This review emphasizes organic inhibitors derived from natural sources, such as amino acids, biopolymers, plant extracts, and environmentally benign synthetic compounds. Additionally, compounds synthesized through ultrasound and microwave irradiation, polyethylene glycols, ionic liquids, and multicomponent reactions are also considered environmentally friendly potential candidates to inhibit corrosion. The chemicals or compounds synthesized using water, ionic liquids, and supercritical carbon dioxide are also green corrosion inhibitors (CIs). Industrial processes such as oil extraction and gas transportation, where equipment are exposed to highly acidic environments, face significant corrosion challenges. Therefore, organic, green, eco-friendly, and cost-effective CIs are the primary demands of industry, researchers, and society. The development of new efficient green CIs can lead to the current research towards a sustainable pathway for future generations. In this context, researchers are continually working to develop more efficient CIs with the least hazardous environmental effects. The mechanisms of action, structural characteristics, and adsorption behaviour of OCIs are discussed in detail, along with their applicability in corrosive environments, such as oil wells, pipelines, and marine systems. This review provides a comprehensive overview of corrosion fundamentals, different classes of OCIs, key factors responsible for corrosion inhibition, mechanistic pathways, molecular modelling, and artificial neural networks for determining the rate of corrosion, followed by a future prospective. This review aims to support ongoing research efforts towards the sustainable corrosion control, offering valuable insights for scientists, engineers, and industries striving for greener and more cost-effective corrosion mitigation strategies.