Sustainable plant extracts for corrosion protection of brass alloys: performance evaluation and mechanistic insights

Brass alloys, which are widely used in industrial and engineering applications, are susceptible to corrosion, particularly dezincification, which can compromise their performance and service life. Although conventional inorganic inhibitors are effective, concerns regarding their toxicity and environmental impact have driven the search for sustainable alternatives. Plant extracts have been widely recognized as promising environmentally friendly corrosion inhibitors. Their phytochemical constituents inhibit corrosion primarily through adsorption onto brass surfaces and the formation of protective films. Owing to their biodegradability, renewability, low cost, and rich phytochemical composition, these natural products represent attractive, environmentally friendly alternatives. This review critically examines recent advances in the use of plant-derived inhibitors for brass corrosion protection by integrating findings from experimental studies and theoretical investigations. Key aspects discussed include inhibition efficiency, electrochemical and surface characterization techniques, adsorption behavior, corrosion inhibition mechanisms, and the factors influencing inhibitor performance. The review also discusses the current challenges and emerging opportunities associated with the development and industrial adoption of environmentally benign corrosion inhibitors for brass alloys.