Atmospheric corrosion in H₂S–impacted tropical marine environments: Mechanisms, materials degradation and mitigation strategies–A comprehensive review

Since 2011, recurrent massive strandings of pelagic Sargassum across the Caribbean have generated a new class of tropical coastal atmospheres enriched in hydrogen sulfide (H2S), high humidity, and marine aerosol deposits. These environmental conditions are increasingly recognized as key factors influencing atmospheric corrosion processes and infrastructure durability in affected regions. In this review, we critically synthesized knowledge on the atmospheric corrosion behavior of copper, zinc, and carbon steel in tropical marine environments impacted by Sargassum-derived H2S. Emphasis was placed on reported mechanisms, corrosion product formation, and synergistic interactions between sulfide and chloride species described in the literature. Available studies consistently indicate that H2S alters conventional corrosion pathways, promoting sulfide-dominated surface layers that are generally porous and weakly protective compared with oxide-based films formed in classical marine atmospheres. We also examined advances in mitigation strategies, particularly bio-derived self-assembled monolayers obtained from Sargassum extracts, highlighting their reported protective performance and limitations. By integrating findings from field investigations, published experimental studies, and comparative analyses, we provided a consolidated mechanistic framework and identified key research gaps necessary for improving corrosion prediction and protection strategies in sulfur-impacted coastal environments.