Atriplex leucoclada extract: A promising eco-friendly anticorrosive agent for copper in aqueous media

https://doi.org/10.1016/j.jiec.2021.04.042Get rights and content

Abstract

Conventional organic and inorganic corrosion inhibitors are noxious and hazardous to living organisms and the environment. Therefore, the use of plant extracts as potential corrosion inhibitors for metals has attracted considerable attention because these compounds are renewable and can have low toxicity, mainly when derived from edible plant species. Here, we prepared Atriplex leucoclada extract (ALE, 0–8 g/L) and tested its effectiveness as an eco-friendly copper corrosion inhibitor in 1 M HCl using several characterisation techniques, such as potentiodynamic polarisation experiments at the open-circuit potential, electrochemical impedance spectroscopy, and surface morphology. Adsorption isotherm modelling based on the Langmuir monolayer adsorption model revealed that the antioxidant flavonoids and polyphenolic compounds in ALE adsorb on the surface of copper and act as mixed-type inhibitors to reduce copper corrosion. Notably, the use of ALE resulted in a high (91.5%) inhibition efficiency at room temperature. Our results demonstrate the potential of ALE as a corrosion inhibitor for copper in acidic media and enrich knowledge regarding the use of plant extracts as green corrosion inhibitors.

Introduction

Copper is an important metal and is used in heat exchangers, electrical and electronic appliances, and in the power and aerospace industries [1], [2], [3] because of its high electrical conductivity [4], high thermal conductivity, ductility, strength, chemical stability [5], and weldability. Although copper is relatively resistant to corrosion by common chemicals and by the atmosphere, it is easily corroded in harsh environments, such as in strongly acidic media. However, the use of corrosion inhibitors can address this problem [6]. To date, many corrosion inhibitors have been developed, including synthetic organic and inorganic compounds. Initially, inorganic inhibitors were widely used because they are highly effective in preventing the corrosion of pure copper. However, the use of these materials has been increasingly restricted because of their high toxicity and environmentally unfriendly nature. Organic corrosion inhibitors are typically unsaturated compounds that contain O, N, S, P, and active functional groups. The functional groups and π-bonds are effective for corrosion inhibition [7], [8], [9], [10], [11], [12] because they form a protective layer on the metal surface, thus serving as a barrier between the corrosive medium and the metal surface [13], [14]. Hence, the corrosion of metal surfaces can be significantly reduced using organic inhibitors. However, these inhibitors have several disadvantages, including exhaustible resources and high costs. Consequently, there is a need to develop effective green corrosion inhibitors that are non-toxic, inexpensive, and can be prepared from renewable resources [15], [16], [17], [18], [19].

Green corrosion inhibitors are environment-friendly because they do not contain heavy metals or harmful chemicals and are biodegradable [20]. Plant materials are herbal in nature, widely available, inexpensive, and contain tannins, phenolics, organic and amino acids, alkaloids, and flavonoids, which are believed to possess corrosion-inhibitory properties [21]. Furthermore, simple procedures can be used to extract these materials from plants at a low cost. With the development of science and technology, considerable importance has been placed on environmental protection. Accordingly, several plant extracts have attracted attention as anticorrosive agents. These natural extracts are promising sources of effective natural active antioxidants, many of which can be considered safe [22], [23], [24], [25], [26], [27], [28], [29], [30]. Natural products, such as Egyptian licorice extract [31], Rosa canina fruit extract [32], aloe plant extract [33], mimosa extract [34], Santolina chamaecyparissus extract [35], Rollinia occidentalis extract [36], watermelon rind extract [37], nettle leaf extract [38], Urtica dioica extract [39], plant-derived cationic dye [40], inulin [41], and Artemisia mesatlantica essential oil [42], have recently been confirmed to be effective in reducing metal corrosion rates in corrosive media. The corrosion-inhibiting activity such extracts is often due to some of their organic constituents (phytochemicals), which have electronic structures similar to those of traditional organic corrosion inhibitors. The existence of complex organic compounds containing nitrogen, oxygen, and sulfur atoms and triple bonds, conjugated double bonds, or aromatic rings, which are the main adsorption centres, in the molecular structures increase the corrosion-inhibition efficiency of these plant extracts.

In this study, we evaluated the anti-corrosive properties of Atriplex leucoclada is a plant that grows well in desert and saline environments. It contains complex compounds, including organic acids, cardenolides and flavonoids, alkaloids [43], polyphenols, tannins, and phosphatidylglycerol [44], [45], [46], [47], which are potential corrosion inhibitors. In fact, some of these compounds have been used in previous studies as corrosion inhibitors. These compounds form a protective layer on the Cu surface; thus, they efficiently separate the corrosive medium from the copper surface [48], [49], [50], [51]. However, to date, A. leucoclada has not been investigated as a source of green corrosion inhibitors. Therefore, in this study, we investigated the ability of A. leucoclada extract (ALE) to prevent the corrosion of copper in an acidic environment (1 M aqueous HCl). We harvested specimens of A. leucoclada during July 2019 from a region of western Iraq that experiences a moderate and dry climate. ALE was prepared, and its components were analysed via gas-chromatography–mass spectrometry (GC–MS), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), electrochemical analysis, scanning electron microscopy (SEM), and energy dispersive X-ray analysis to gain insight into the mechanism of the corrosion inhibition of copper in 1 M HCl. The adsorption type and mechanism responsible for protecting the Cu surface from corrosion were also examined through adsorption experiments.

Section snippets

Electrode and corrosion medium formation

For the electrochemical analyses, copper electrodes were sealed in epoxy resin to leave only their square faces (1 × 1 cm) exposed to the corrosive HCl solution. For the AFM and XPS studies, plate-like specimens (1.0 × 0.1 × 0.1 cm) were prepared from high-purity (99.99%) copper. In addition, cubic specimens (2 × 2 × 2 cm) were prepared for the electrochemical experiments and SEM observation (0.5 × 0.5 × 0.5 cm). The specimens were carefully and sequentially abraded with clean emery paper with a fineness from

Gas-chromatography–mass spectrometry results

ALE contains complex components, that may have an inhibitory effect on corrosion. In this study, GC–MS was conducted to determine the constituents of ALE. The most important and most abundant components are listed in Table 1. References to studies that identified these components as green corrosion inhibitors are also provided.

FTIR analysis

Fig. 1 presents the FTIR spectrum of ALE, which was used to determine the functional groups of the ALE constituents adsorbed on the copper surface. The broad band at

Conclusions

In this study, the ability of ALE to act as a green corrosion inhibitor for copper under highly acidic conditions was investigated. The main components of ALE were identified via GCsingle bondMS, and FTIR spectroscopy revealed the presence of the same functional groups as those identified through the GCsingle bondMS analysis. These functional groups are appropriate for interaction of ALE components with a copper surface and thus enable the formation of a protective film. Based on the results of Tafel analysis, we

Declaration of interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work was supported by the Chinese National Foundation for Natural Science [grant numbers 21878029, 21676035, and 21706195] and the Guangdong, China Sail Programme [grant number 2015YT02D025].

References (78)

  • H. Li et al.

    J. Mol. Liq.

    (2020)
  • B. Tan et al.

    J. Ind. Eng. Chem.

    (2019)
  • D.S. Chauhan et al.

    J. Mol. Liq.

    (2019)
  • X. Zhang et al.

    J. Mol. Liq.

    (2021)
  • Q. Xiang et al.

    J. Mol. Liq.

    (2021)
  • A. Mishra et al.

    J. Mol. Liq.

    (2018)
  • V. Srivastava et al.

    J. Mol. Liq.

    (2021)
  • Z. Sanaei et al.

    J. Ind. Eng. Chem.

    (2019)
  • P. Dohare et al.

    J. Ind. Eng. Chem.

    (2017)
  • L. Rassouli et al.

    J. Ind. Eng. Chem.

    (2018)
  • M. Motamedi et al.

    J. Ind. Eng. Chem.

    (2018)
  • M.A. Deyab

    J. Ind. Eng. Chem.

    (2015)
  • B. Tan et al.

    J. Colloid Interface Sci.

    (2019)
  • D.S. Chauhan et al.

    J. Mol. Liq.

    (2020)
  • M. Shabani-Nooshabadi et al.

    J. Ind. Eng. Chem.

    (2015)
  • D.S. Chauhan et al.

    J. Mol. Struct.

    (2021)
  • A. Dehghani et al.

    J. Ind. Eng. Chem.

    (2020)
  • L. Guo et al.

    J. Colloid Interface Sci.

    (2020)
  • I.B. Obot et al.

    J. Ind. Eng. Chem.

    (2019)
  • K. Dahmani et al.

    Inorg. Chem. Commun.

    (2021)
  • M.T. Majd et al.

    J. Hazard. Mater.

    (2020)
  • H. Li et al.

    Colloids Surf.

    (2021)
  • Z. Jiang et al.

    J. Mol. Liq.

    (2021)
  • R. Haldhar et al.

    J. Mol. Liq.

    (2021)
  • M.M. Solomon et al.

    J. Colloid Interface Sci.

    (2019)
  • S. Chen et al.

    J. Mol. Liq.

    (2020)
  • M. Prabakaran et al.

    J. Ind. Eng. Chem.

    (2017)
  • X. Zuo et al.

    J. Mol. Liq.

    (2021)
  • M.A. Deyab

    J. Ind. Eng. Chem.

    (2015)
  • Z. Sanaei et al.

    J. Ind. Eng. Chem.

    (2019)
  • M. Mehdipour et al.

    J. Ind. Eng. Chem.

    (2015)
  • H. Gerengi et al.

    J. Ind. Eng. Chem.

    (2012)
  • M. Shabani-Nooshabadi et al.

    J. Ind. Eng. Chem.

    (2015)
  • P.E. Alvarez et al.

    J. Ind. Eng. Chem.

    (2018)
  • N.A. Odewunmi et al.

    J. Ind. Eng. Chem.

    (2015)
  • M. Ramezanzadeh et al.

    J. Ind. Eng. Chem.

    (2019)
  • M. Mahmudzadeh et al.

    J. Ind. Eng. Chem.

    (2019)
  • A. Singh et al.

    J. Ind. Eng. Chem.

    (2014)
  • Charitha B P et al.

    J. Ind. Eng. Chem.

    (2018)
  • Cited by (17)

    • Novel method for protecting copper: An in-situ click-assembly film on copper surface

      2023, Colloids and Surfaces A: Physicochemical and Engineering Aspects
    View all citing articles on Scopus
    View full text