Effect of Acid Extract of Leaves of Juniperus procera on Corrosion Inhibition of Carbon Steel in HCl Solutions

Abstract

The efficiency of the hydrochloric acid leaf extract of Juniperus procera as a corrosion inhibitor against C-steel and its adsorption behavior were investigated in 1.0 M HCl solution using mass loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) techniques. Results revealed that the inhibition efficiency increased with the inhibitor concentration. EIS spectra exhibited one capacitive loop and confirmed the inhibitive capacity. The activation energy (E a ) of the corrosion process clearly increased when the extract was used. The leaf extract was found to act as mixed-type inhibitor. The inhibition properties of the extract are discussed in terms of the mechanism by which its components adsorb onto the C-steel surface. This adsorption process obeyed a Langmuir adsorption isotherm.

Secondary Plant Metabolites of Natural Product Origin—<i>Strongylodon macrobotrys</i> as Pitting Corrosion Inhibitors of Steel around Heavy Salt Deposits in Gabu, Nigeria

“…So the high corrosion potential values exhibited by the inhibitors proved the inhibitors as good ones. Table 3 and Figures 4(a)-(c) also show a reduction in the corrosion rate and a negligible shift in the corrosion potential (in this case a slight increase) indicating that the inhibitors are mixed type inhibitors [44] [51] [52] [53]. This can also be confirmed from the anodic and cathodic slope values in Table 3.…”

“…It also shows that the inhibitors are physically adsorbed on the metal surfaces. The regression values (R 2 ) were very close to unity, an indication revealing the good fitting of the data to the isotherm and the fact that all the adsorbed inhibitor molecules are in contact with the surface layer of the adsorbent (mild steel)[42] [43][44] [56][59]. The slope value for the Langmuir plots is greater than unity, indicating a strong relationship between the species adsorbed.…”

“…This increase gave rise to maximum inhibition efficiency of 89.54, 71.14 and 68.10 for AESML, SESML and FESML respectively. This can be explained from the fact that the corrosion rate of steel in sea water is almost always rate limited by the cathodic reaction and by the mass transport of oxidizers (dissolved oxygen) to the surface hence, giving way for more inhibition at the anodic dissolution of the metal[14] [31][40] [43][44]…”

Cysteine as an Eco-Friendly Anticorrosion Inhibitor for Mild Steel in Various Acidic Solutions: Electrochemical, Adsorption, Surface Analysis, and Quantum Chemical Calculations

“…Cys. adsorption molecules are found in the MSL interface or solution as a result. − Nyquist plots were not close as predicted and revealed a departure from EIS theory. Due to frequency dispersion and the variability of the MSL surface, semicircle mismatch is observed instead of the perfect condition …”

Bioactive compounds from Juniperus procera (Cupressaceae) with activity against common bean bacterial pathogens

“…Also, a concoction prepared from boiled roots and bark is used for cancer treatment by the Kalenjin community in Kenya (Kigen et al, 2017). Studies have also reported that extracts from the plant possess phytochemical compounds like triterpenes, flavonoids, tannins, saponins, and alkaloids (Ali and Suleiman, 2018). Pharmacological studies of extracts have reported the presence of antimalarial, antioxidant, antileishmanial, nematicidal and antibacterial compounds (Mossa et al, 2004;Samoylenko et al, 2008;Alqasoumi and Abdel-Kader, 2012;Samaha et al, 2017).…”