Adsorption and corrosion inhibition accomplishment for thiosemicarbazone derivatives for mild steel in 1.0 M HCl medium: Electrochemical, XPS and DFT studies
Four benzaldehyde thiosemicarbazone derivatives namely as 2-benzylidene-N-phenylhydrazinecarbothioamide (L1), 2-(4-hydroxybenzylidene)-N-phenylhydrazinecarbothioamide (L2), 2-(4-chlorobenzylidene)-Nphenylhydrazinecarbothioamide (L3), and 2-(4-methylbenzylidene)-N-phenylhydrazinecarbothioamide (L4...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
2021
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/1130/ http://eprints.uthm.edu.my/1130/1/JCR_J12026_b1816f6b7f19467ad4859cf312e5938e.pdf |
| _version_ | 1848887382702555136 |
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| author | Zaidon, Fazhrul Haqimee Kassim, Karimah Mohd Zaki, Hamizah Embong, Zaidi Anouar, El Hassane |
| author_facet | Zaidon, Fazhrul Haqimee Kassim, Karimah Mohd Zaki, Hamizah Embong, Zaidi Anouar, El Hassane |
| author_sort | Zaidon, Fazhrul Haqimee |
| building | UTHM Institutional Repository |
| collection | Online Access |
| description | Four benzaldehyde thiosemicarbazone derivatives namely as 2-benzylidene-N-phenylhydrazinecarbothioamide
(L1), 2-(4-hydroxybenzylidene)-N-phenylhydrazinecarbothioamide (L2), 2-(4-chlorobenzylidene)-Nphenylhydrazinecarbothioamide
(L3), and 2-(4-methylbenzylidene)-N-phenylhydrazinecarbothioamide
(L4) were successfully synthesized and elucidated by physical and spectral techniques, to be specific,melting
point, elemental analysis (CHNS), infrared spectroscopy (FTIR) and 1H and 13C nuclear magnetic resonance
spectroscopy (NMR). These organic corrosion inhibitors behaviour for mild steel (MS) in 1.0 M HCl solution was
examined using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques.
Fromthe electrochemical measurements, most ligands behave as efficient inhibitors for theMS in 1.0MHCl solution
which contribute the maximum inhibition efficiency up to 93.38% for L3. The potentiodynamic polarization
measurements unfolds each synthesized compoundweremixed-type inhibitor based on the shifting of corrosion
potentials (Ecorr) found to be lesser than±85 mV. The electrochemical impedance spectroscopy (EIS) analysis revealed
retardation of metal corrosion succeeded by cause of adsorption of the four thiosemicarbazone derivatives
inhibitor molecules at the metal/solution interface. The adsorption of thiosemicarbazone molecules on the low
carbon steel surface in 1.0 M HCl solution obeys Langmuir adsorption isotherm. Scanning electron microscopy
(SEM) and atomic force microscopy (AFM) demonstrates in the presence of optimum concentration of L1-L4
inhibitors at 0.04mMindicates greatly reduced surface roughness ofMS in comparisonwith uninhibited solution.
The findingswere further reinforced via surface elemental analysis ofmetal/solution interface viaX-ray Photoelectron
Spectroscopy (XPS), which unveils L3 exhibit the greatest inhibition efficiency. The most plausible reason is
due to benzene rings in the molecular structure increases the adsorption ability in supporting the substituent of
chloro as well as conjugated double bond of C=N and C=S that chemisorbed along the surface of metal. The
oxide species of FeO, Fe2O3 and FeOOH found to be chemisorbed and physisorbed on MS surface. The impact of
molecular properties on the corrosion inhibition and the adsorbed sites of L1-L4 on the metal were investigated
using density functional theory calculations (DFT) at the B3LYP/6–311+G (d,p) level of theory. Fromthe Frontier
Molecular Orbitals (FMO), the Highest OccupiedMolecular Orbitals (HOMO) discloses adsorption of L2 on theMS
surface generally due to 2-(4-hydroxybenzylidene)-N-hydrazinecarbothioamide, whereas for L1, L3 and L4 associated
to the inclusion of phenyl carbothioamide. The Lowest Occupied Molecular Orbitals (LUMOs) of L1-L4 are
comparatively resembling and delocalized of all molecules. DFT reveals protonated thiosemicarbazones exhibits
high correlations coefficients as up to 99–100% in comparison to the corresponding neutral forms of themolecules.
The increase in the inhibition efficiency of protonated L1, L2 and L3 is proportional to the ΔN and DM. |
| first_indexed | 2025-11-15T19:53:30Z |
| format | Article |
| id | uthm-1130 |
| institution | Universiti Tun Hussein Onn Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T19:53:30Z |
| publishDate | 2021 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | uthm-11302021-10-17T07:58:04Z http://eprints.uthm.edu.my/1130/ Adsorption and corrosion inhibition accomplishment for thiosemicarbazone derivatives for mild steel in 1.0 M HCl medium: Electrochemical, XPS and DFT studies Zaidon, Fazhrul Haqimee Kassim, Karimah Mohd Zaki, Hamizah Embong, Zaidi Anouar, El Hassane TS Manufactures Four benzaldehyde thiosemicarbazone derivatives namely as 2-benzylidene-N-phenylhydrazinecarbothioamide (L1), 2-(4-hydroxybenzylidene)-N-phenylhydrazinecarbothioamide (L2), 2-(4-chlorobenzylidene)-Nphenylhydrazinecarbothioamide (L3), and 2-(4-methylbenzylidene)-N-phenylhydrazinecarbothioamide (L4) were successfully synthesized and elucidated by physical and spectral techniques, to be specific,melting point, elemental analysis (CHNS), infrared spectroscopy (FTIR) and 1H and 13C nuclear magnetic resonance spectroscopy (NMR). These organic corrosion inhibitors behaviour for mild steel (MS) in 1.0 M HCl solution was examined using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Fromthe electrochemical measurements, most ligands behave as efficient inhibitors for theMS in 1.0MHCl solution which contribute the maximum inhibition efficiency up to 93.38% for L3. The potentiodynamic polarization measurements unfolds each synthesized compoundweremixed-type inhibitor based on the shifting of corrosion potentials (Ecorr) found to be lesser than±85 mV. The electrochemical impedance spectroscopy (EIS) analysis revealed retardation of metal corrosion succeeded by cause of adsorption of the four thiosemicarbazone derivatives inhibitor molecules at the metal/solution interface. The adsorption of thiosemicarbazone molecules on the low carbon steel surface in 1.0 M HCl solution obeys Langmuir adsorption isotherm. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrates in the presence of optimum concentration of L1-L4 inhibitors at 0.04mMindicates greatly reduced surface roughness ofMS in comparisonwith uninhibited solution. The findingswere further reinforced via surface elemental analysis ofmetal/solution interface viaX-ray Photoelectron Spectroscopy (XPS), which unveils L3 exhibit the greatest inhibition efficiency. The most plausible reason is due to benzene rings in the molecular structure increases the adsorption ability in supporting the substituent of chloro as well as conjugated double bond of C=N and C=S that chemisorbed along the surface of metal. The oxide species of FeO, Fe2O3 and FeOOH found to be chemisorbed and physisorbed on MS surface. The impact of molecular properties on the corrosion inhibition and the adsorbed sites of L1-L4 on the metal were investigated using density functional theory calculations (DFT) at the B3LYP/6–311+G (d,p) level of theory. Fromthe Frontier Molecular Orbitals (FMO), the Highest OccupiedMolecular Orbitals (HOMO) discloses adsorption of L2 on theMS surface generally due to 2-(4-hydroxybenzylidene)-N-hydrazinecarbothioamide, whereas for L1, L3 and L4 associated to the inclusion of phenyl carbothioamide. The Lowest Occupied Molecular Orbitals (LUMOs) of L1-L4 are comparatively resembling and delocalized of all molecules. DFT reveals protonated thiosemicarbazones exhibits high correlations coefficients as up to 99–100% in comparison to the corresponding neutral forms of themolecules. The increase in the inhibition efficiency of protonated L1, L2 and L3 is proportional to the ΔN and DM. 2021 Article PeerReviewed text en http://eprints.uthm.edu.my/1130/1/JCR_J12026_b1816f6b7f19467ad4859cf312e5938e.pdf Zaidon, Fazhrul Haqimee and Kassim, Karimah and Mohd Zaki, Hamizah and Embong, Zaidi and Anouar, El Hassane (2021) Adsorption and corrosion inhibition accomplishment for thiosemicarbazone derivatives for mild steel in 1.0 M HCl medium: Electrochemical, XPS and DFT studies. Journal of Molecular Liquids, 329. pp. 1-15. https://doi.org/10.1016/j.molliq.2021.115553 |
| spellingShingle | TS Manufactures Zaidon, Fazhrul Haqimee Kassim, Karimah Mohd Zaki, Hamizah Embong, Zaidi Anouar, El Hassane Adsorption and corrosion inhibition accomplishment for thiosemicarbazone derivatives for mild steel in 1.0 M HCl medium: Electrochemical, XPS and DFT studies |
| title | Adsorption and corrosion inhibition accomplishment for
thiosemicarbazone derivatives for mild steel in 1.0 M HCl medium:
Electrochemical, XPS and DFT studies |
| title_full | Adsorption and corrosion inhibition accomplishment for
thiosemicarbazone derivatives for mild steel in 1.0 M HCl medium:
Electrochemical, XPS and DFT studies |
| title_fullStr | Adsorption and corrosion inhibition accomplishment for
thiosemicarbazone derivatives for mild steel in 1.0 M HCl medium:
Electrochemical, XPS and DFT studies |
| title_full_unstemmed | Adsorption and corrosion inhibition accomplishment for
thiosemicarbazone derivatives for mild steel in 1.0 M HCl medium:
Electrochemical, XPS and DFT studies |
| title_short | Adsorption and corrosion inhibition accomplishment for
thiosemicarbazone derivatives for mild steel in 1.0 M HCl medium:
Electrochemical, XPS and DFT studies |
| title_sort | adsorption and corrosion inhibition accomplishment for
thiosemicarbazone derivatives for mild steel in 1.0 m hcl medium:
electrochemical, xps and dft studies |
| topic | TS Manufactures |
| url | http://eprints.uthm.edu.my/1130/ http://eprints.uthm.edu.my/1130/ http://eprints.uthm.edu.my/1130/1/JCR_J12026_b1816f6b7f19467ad4859cf312e5938e.pdf |