Corrosion Inhibition of Mild Steel and 304 Stainless Steel in 1 M Hydrochloric Acid Solution by Tea Tree Extract and Its Main Constituents

Abstract

Tea tree extract, containing antioxidant constituents α-terpineol, terpinen-4-ol, and α-terpinene, has a wide range of applications in the cosmetic, food, and pharmaceutical industries. In this study, tea tree extract showed an anticorrosive effect under 1 M HCl solution on mild steel (MS) and 304 stainless steel (STS). Uniform corrosion for MS and pitting corrosion for STS at 298 K were retarded, with inhibition efficiencies of 77% and 86%, respectively. The inhibition of uniform and pitting corrosion was confirmed by scanning electron microscopy and laser scanning confocal microscopy in terms of surface roughness and pitting morphologies. The most effective constituent contributing to the inhibitory performance of tea tree extract was revealed to be α-terpineol, with an inhibition efficiency of 83%. The adsorption of tea tree extract was confirmed by surface characterization analysis using Fourier transform infrared spectroscopy, Raman spectroscopy, and Electrochemical impedance spectroscopy. Interestingly, G- and D-peaks of Raman spectra were detected from the inhibited steels, and this finding is the first example in the corrosion inhibition field. The anticorrosion mechanism can be explained by the formation of organic-Fe complexes on the corroded steel surface via electron donor and acceptor interactions in the presence of an oxygen atom of the hydroxyl group or ether of organic inhibitors.

An Integrated Experimental and Theoretical Studies on the Corrosion Inhibition of Carbon Steel by Harmal Extracts

“…The corrosion inhibition efficiency of steel by Harmal roots, leaves, and flower extracts in sulfuric acid media was compared with other ones reported in the literature, Table 11 . The results showed that the three Harmal extracts studied at a low concentration of 83 ppm with high IE % (93%), averaged from the three extracts, are more effective towards the inhibition of C-steel corrosion compared to other reported ones: Date palm seed (2000 ppm, 91%) [ 58 ], tea tree (2250 ppm, 78.6%) [ 59 ], Ginkgo leaf extract (200 ppm, 90.0%) [ 60 ], and Brassica oleracea L (300 ppm, 92.7%) [ 61 ].…”

Nanoporous silver fabricated with pretreated Ag–Al alloy toward surface enhanced Raman sensing

“…Undealloyed α-TPN@ Ag 55 Al 45 did not exhibit effective SERS enhancement, hence a characteristic peak around 3600 cm −1 for the line V was not observed. However, a small amount of α-TPN on the surface could still be proved due to the peak caused by the C-H stretching vibrations at around 2800-3000 cm −1 [42]. On the other hand, a weak peak at 3594 cm −1 corresponding to the O-H stretching was found in line VI samples and some peaks were at around 2800-3000 cm −1 .…”

Laboratory Evaluation of a Low-Damage Authigenic Mud Acid System for Bai-823 Well Block

“…A standard solution of NaOH at 1.0 mol/L was used to titrate the authigenic acid mixture with the addition of phenolphthalein, and the change in H + concentration in the authigenic acid system with time was calculated by the consumption of lye. The formula for calculating H + is shown in eq . , C acid = C NaOH × V t V acid where C acid is the H + concentration in the acid system, mol/L; C NaOH is the OH – concentration in the lye system, mol/L; V t is the volume of lye for titration, mL; and V acid is the acid volume, mL.…”

“…The formula for calculating H + is shown in eq 1 . 23 , 24 where C acid is the H + concentration in the acid system, mol/L; C NaOH is the OH – concentration in the lye system, mol/L; V t is the volume of lye for titration, mL; and V acid is the acid volume, mL.…”