Algae-based corrosion inhibitors as innovative approaches to corrosion prevention: A review

Abstract

Corrosion poses a significant threat to industries, lives, and property, making its management essential from technical, financial, environmental, and aesthetic perspectives. Corrosion inhibitors, particularly synthetic chemicals, are widely used but often toxic and costly. This has led to increased interest in eco-friendly alternatives, especially green corrosion inhibitors derived from algae extracts. Algae are abundant sources of biodegradable and non-toxic biomaterials, which have shown promise as effective corrosion inhibitors due to their unique chemical properties. Despite extensive research on green-based compounds in recent years, there is a lack of comprehensive reviews focusing specifically on algal extracts as corrosion inhibitors for metals. Existing reviews predominantly focus on terrestrial plant-based inhibitors or other bio-sourced materials, with only limited studies addressing algae-derived inhibitors. These studies are typically restricted to specific algae species or narrow experimental conditions, lacking comprehensive synthesis. This review uniquely bridges this research gap by providing a detailed analysis of both microalgae (e.g., Chlorella, Spirulina, etc) and macroalgae (e.g., Sargassum, etc) as sustainable corrosion inhibitors for ferrous alloys across various corrosive environments, including acidic and saline media. It systematically explores their mechanisms of action, advantages, limitations, and synergistic potential with other corrosion inhibitors. Furthermore, the present paper incorporates a comparative analysis of algae-derived inhibitors with traditional ones from various research studies, highlighting their distinct inhibition efficiency, biochemical properties, sustainability, and versatility. By addressing challenges such as compositional variability, stability, and scalability, this paper underscores the transformative role of algae-based inhibitors and encourages innovation in corrosion prevention strategies. The integration of recent findings consolidates evidence for their application in diverse corrosive media, positioning algae-derived inhibitors as a promising solution for sustainable industrial use.