Electrochemical performance of a novel 1-(benzo[d]thiazol-2-yl)-3-methylguanidine as effective corrosion inhibitor for carbon steel in 1 M hydrochloric acid

Abstract Guanidine benzothiazole (G) and 1-(benzo[d]thiazol-2-yl)-3-methylguanidine (AG) were successfully synthesized and characterized by infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Both compounds act as novel corrosion inhibitors for carbon steel in 1.0 M hydrochloric acid...

Full description

Saved in:
Bibliographic Details
Main Authors: Amal M. Abdel-karim, Rasha A. Azzam, Omnia El-Said Shehata, Mohamed A. adly, Omnia A. A. El-Shamy, Gamal A. El mahdy
Format: Article
Language:English
Published: Nature Portfolio 2025-08-01
Series:Scientific Reports
Subjects:
Online Access:https://doi.org/10.1038/s41598-025-12838-2
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849763453014638592
author Amal M. Abdel-karim
Rasha A. Azzam
Omnia El-Said Shehata
Mohamed A. adly
Omnia A. A. El-Shamy
Gamal A. El mahdy
author_facet Amal M. Abdel-karim
Rasha A. Azzam
Omnia El-Said Shehata
Mohamed A. adly
Omnia A. A. El-Shamy
Gamal A. El mahdy
author_sort Amal M. Abdel-karim
collection DOAJ
description Abstract Guanidine benzothiazole (G) and 1-(benzo[d]thiazol-2-yl)-3-methylguanidine (AG) were successfully synthesized and characterized by infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Both compounds act as novel corrosion inhibitors for carbon steel in 1.0 M hydrochloric acid solution. Their inhibition efficiency was evaluated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Surface analysis via scanning electron microscope (SEM) and energy dispersive X-ray (EDX) confirmed the formation of a protective film on the steel surface. PDP results indicate that G and AG function as mixed-type inhibitors, with inhibition efficiency increasing with concentrations, reaching a maximum of 80% for G and 91.4% AG. The AG compound was seen to retard the rate of corrosion of carbon steel more effective than PP compound. Adsorption followed the Langmuir isotherm, suggesting monolayer adsorption on the metal surface. The high inhibition efficiencies were attributed to strong adsorption and the formation of a dense, protective barrier film. The corrosion inhibition performance of the synthesized molecule was evaluated using density functional theory (DFT). Quantum chemical parameters, including highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO), energy gap, hardness, and dipole moment, and other quantum descriptors were analyzed. Density functional theory (DTF) calculation supported the experimental finding, showing that the high efficiency correlates with a low energy gap and high dipole moment, which promote electron transfer and adsorption strength. Theoretical and experimental results showed strong agreement, confirming the potential of G and AG as effective inhibitors for carbon steel.
format Article
id doaj-art-ef02b2ca663b475fab10bbcf9a039614
institution DOAJ
issn 2045-2322
language English
publishDate 2025-08-01
publisher Nature Portfolio
record_format Article
series Scientific Reports
spelling doaj-art-ef02b2ca663b475fab10bbcf9a0396142025-08-20T03:05:25ZengNature PortfolioScientific Reports2045-23222025-08-0115111610.1038/s41598-025-12838-2Electrochemical performance of a novel 1-(benzo[d]thiazol-2-yl)-3-methylguanidine as effective corrosion inhibitor for carbon steel in 1 M hydrochloric acidAmal M. Abdel-karim0Rasha A. Azzam1Omnia El-Said Shehata2Mohamed A. adly3Omnia A. A. El-Shamy4Gamal A. El mahdy5Physical Chemistry Department, National Research CentreCemistry Department, Faculty of Science, Helwan UniversityPhysical Chemistry Department, National Research CentreCemistry Department, Faculty of Science, Helwan University3Department of Analysis and Evaluation, Egyptian Petroleum Research Institute (EPRI)Cemistry Department, Faculty of Science, Helwan UniversityAbstract Guanidine benzothiazole (G) and 1-(benzo[d]thiazol-2-yl)-3-methylguanidine (AG) were successfully synthesized and characterized by infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Both compounds act as novel corrosion inhibitors for carbon steel in 1.0 M hydrochloric acid solution. Their inhibition efficiency was evaluated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Surface analysis via scanning electron microscope (SEM) and energy dispersive X-ray (EDX) confirmed the formation of a protective film on the steel surface. PDP results indicate that G and AG function as mixed-type inhibitors, with inhibition efficiency increasing with concentrations, reaching a maximum of 80% for G and 91.4% AG. The AG compound was seen to retard the rate of corrosion of carbon steel more effective than PP compound. Adsorption followed the Langmuir isotherm, suggesting monolayer adsorption on the metal surface. The high inhibition efficiencies were attributed to strong adsorption and the formation of a dense, protective barrier film. The corrosion inhibition performance of the synthesized molecule was evaluated using density functional theory (DFT). Quantum chemical parameters, including highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO), energy gap, hardness, and dipole moment, and other quantum descriptors were analyzed. Density functional theory (DTF) calculation supported the experimental finding, showing that the high efficiency correlates with a low energy gap and high dipole moment, which promote electron transfer and adsorption strength. Theoretical and experimental results showed strong agreement, confirming the potential of G and AG as effective inhibitors for carbon steel.https://doi.org/10.1038/s41598-025-12838-2Carbon steelGuanidine benzothiazoleCorrosion inhibitorPDPEISAdsorption
spellingShingle Amal M. Abdel-karim
Rasha A. Azzam
Omnia El-Said Shehata
Mohamed A. adly
Omnia A. A. El-Shamy
Gamal A. El mahdy
Electrochemical performance of a novel 1-(benzo[d]thiazol-2-yl)-3-methylguanidine as effective corrosion inhibitor for carbon steel in 1 M hydrochloric acid
Scientific Reports
Carbon steel
Guanidine benzothiazole
Corrosion inhibitor
PDP
EIS
Adsorption
title Electrochemical performance of a novel 1-(benzo[d]thiazol-2-yl)-3-methylguanidine as effective corrosion inhibitor for carbon steel in 1 M hydrochloric acid
title_full Electrochemical performance of a novel 1-(benzo[d]thiazol-2-yl)-3-methylguanidine as effective corrosion inhibitor for carbon steel in 1 M hydrochloric acid
title_fullStr Electrochemical performance of a novel 1-(benzo[d]thiazol-2-yl)-3-methylguanidine as effective corrosion inhibitor for carbon steel in 1 M hydrochloric acid
title_full_unstemmed Electrochemical performance of a novel 1-(benzo[d]thiazol-2-yl)-3-methylguanidine as effective corrosion inhibitor for carbon steel in 1 M hydrochloric acid
title_short Electrochemical performance of a novel 1-(benzo[d]thiazol-2-yl)-3-methylguanidine as effective corrosion inhibitor for carbon steel in 1 M hydrochloric acid
title_sort electrochemical performance of a novel 1 benzo d thiazol 2 yl 3 methylguanidine as effective corrosion inhibitor for carbon steel in 1 m hydrochloric acid
topic Carbon steel
Guanidine benzothiazole
Corrosion inhibitor
PDP
EIS
Adsorption
url https://doi.org/10.1038/s41598-025-12838-2
work_keys_str_mv AT amalmabdelkarim electrochemicalperformanceofanovel1benzodthiazol2yl3methylguanidineaseffectivecorrosioninhibitorforcarbonsteelin1mhydrochloricacid
AT rashaaazzam electrochemicalperformanceofanovel1benzodthiazol2yl3methylguanidineaseffectivecorrosioninhibitorforcarbonsteelin1mhydrochloricacid
AT omniaelsaidshehata electrochemicalperformanceofanovel1benzodthiazol2yl3methylguanidineaseffectivecorrosioninhibitorforcarbonsteelin1mhydrochloricacid
AT mohamedaadly electrochemicalperformanceofanovel1benzodthiazol2yl3methylguanidineaseffectivecorrosioninhibitorforcarbonsteelin1mhydrochloricacid
AT omniaaaelshamy electrochemicalperformanceofanovel1benzodthiazol2yl3methylguanidineaseffectivecorrosioninhibitorforcarbonsteelin1mhydrochloricacid
AT gamalaelmahdy electrochemicalperformanceofanovel1benzodthiazol2yl3methylguanidineaseffectivecorrosioninhibitorforcarbonsteelin1mhydrochloricacid