Combined experimental and computational studies on corrosion inhibition of Houttuynia cordata leaf extract for steel in HCl medium

• Published in: Journal of molecular liquids 2020-10, Vol.315, p.113787, Article 113787
• Main Authors: Thanh, Le Thanh, Vu, Nguyen Si Hoai, Binh, Phan Minh Quoc, Dao, Vinh Ai, Thu, Vu Thi Hanh, Van Hien, Pham, Panaitescu, Casen, Nam, Nguyen Dang
• Format: Article
• Language: English
• Subjects: Carbon steel; Corrosion; Electrochemical methods; Green inhibitor; Hydrochloric acid; Molecular dynamics simulation
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2020.113787

The development of corrosion inhibitors that could spontaneously adsorb immediately on the metal surfaces after they are damaged by electrochemical reactions would remarkably arise the improvement of cost-saving, durability and environmental impact of metals. The use of leaf materials for metal corrosion remains an important challenge due to the high corrosion protection, availability as natural materials, environmental friendly and low-cost. Herein, we report a Houttuynia cordata leaf extract as a green corrosion inhibitor that acts as a mixed type of inhibitor for steel in an aqueous 0.1 M hydrochloric acid solution. It also performs the high inhibition performance (up to 98.3% by adding 1500 ppm inhibitor), spontaneous uniform and smooth film formation of the steel surface and less corrosion attack when the H.cordata leaf extract is added to the aqueous hydrochloric acid solution. In contrast to the inhibited systems, uninhibited specimen is severely corroded at high corrosion rate, which is associated with a significant degradation of the entire steel surface. Additionally, investigation on good adhesion and thermal stability of the protective film, as well as enriched electron abundance of selected inhibitor species are performed via molecular dynamics simulation method. Furthermore, insights of corrosion, inhibition and spontaneous film formation mechanisms are also proposed and discussed in detail. [Display omitted] •A new, low-priced, eco-friendly Houttuynia cordata leaf extract as corrosion inhibitor for steel in HCl solution•HCLE performed a predominant inhibition mechanism on the steel surface in acidic media•Adsorption of HCLE promotes the spontaneous uniform and smooth film formation.•Good adhesion and thermal stability of the protective film•A more comprehensive answer to inhibition mechanism of HCLE on steel in HCl corrosion