Adsorption Of Benzotriazole Research Articles

Benzotriazole Adsorption on Cu2O(111) Surfaces: A First-Principles Study

The adsorption of benzotriazole (BTAH) on Cu2O(111) was investigated with use of first-principles density functional theory calculations. Two possible adsorption structures were considered for both one-quarter and full adsorption coverage. We found that BTAH strongly chemisorbs (1.2−1.5 eV) onto Cu2O(111) by forming a chemical bond with a surface copper atom through nitrogen sp2 lone pairs, and a hydrogen bond with a surface oxygen atom through a C−H or N−H proton. The chemical interaction between the surface copper site and the molecule is the combined effect of a strong lone-pair → hybrid Cu-dz2spz σ-donation and a relatively weak dyz → 6π* back-donation. Vibration calculations were carried out to predict the BTAH−Cu2O stretching frequencies for both adsorption structures. The calculated stretching frequency (381 and 428 cm-1) could overlap with the BTAH benzene-ring torsion band. An estimate for the BTAH−Cu vibrational frequency (226 and 223.4 cm-1 for two adsorption modes, respectively) is in good agr...

Studies of Benzotriazole and Tolytriazole as Inhibitors for Copper Corrosion in Deionized Water

The inhibition efficiencies of benzotriazole (BTA) and tolytriazole (TTA) on copper in deionized water were investigated. The inhibition effects of BTA and TTA were evaluated from polarization curves. Coupon tests established that the inhibition efficiency was concentration, temperature, and time-dependent. Effective inhibition to copper was observed when TTA or BTA (>6 ppm) was added to deionized water. TTA showed more effeciency and persistence for inhibiting the corrosion of copper under selected conditions, which may be attributed to its increased film hydrophobicity. The thermodynamic parameters of BTA and TTA adsorption were calculated.

First principle calculations of benzotriazole adsorption onto clean Cu(1 1 1)

The adsorption of benzotriazole (BTAH or C6N3H5) on a Cu(111) surface is investigated by using first principle density functional theory calculations (VASP). It is found that BTAH can be physisorbed (<0.1 eV) or weakly chemisorbed (∼0.43 eV) onto Cu(111), and the chemical bond is formed through nitrogen sp2 lone pairs. The weak chemisorption can be stabilized by reaction with neighboring protonphilic radicals, like OH−. Furthermore, the geometries and associated energies of intermolecular hydrogen bonds between adsorbates on Cu(111) are also calculated. A model of the first layer of BTAH/BTA− on Cu(111) surface is developed based on a hydrogen bond network structure.

Adsorption of Benzotriazole on Copper Electrode Surfaces in Citric Acid Media

Abstract The corrosion inhibition of copper in 0.001 M to 1.0 M citric acid (C6H8O7) solution by benzotriazole (BTA, C6H5N3) has been investigated using gravimetric measurements. BTA was tested in ...

A Vibrational Structural Analysis of Benzotriazole Adsorption and Phase Film Formation on Copper Using Surface-Enhanced Raman Spectroscopy

The adsorption of benzotriazole (BTAH) on copper in aqueous electrolytes is examined by means of a vibrational analysis utilizing surface-enhanced Raman spectroscopy (SERS) as a function of solvent deuteration, pH, and electrode potential in order to examine adsorbate speciation, surface bonding, and the potential-dependent onset of CuIBTA phase film formation. In acidic media at pH > 1, the monoprotonated acid BTAH constitutes the predominant adsorbate, being replaced by the diprotonated BTAH2+ species by pH 0, and the basic BTA- form in alkaline electrolytes. The analysis of adsorbate speciation is facilitated by the presence of several coupled ring modes yielding vibrational bands in the 1050−1350 cm-1 region that are sensitive to deuteration of the triazole ring nitrogen(s). Insight into the adsorbate molecular geometry and mode of surface attachment is obtained by examining the adsorption-induced alterations in frequency, bandwidth, and relative intensity of the various benzotriazole ring modes. These changes are especially prevalent for triazole ring vibrations and some deuteration-sensitive modes, the latter apparently associated with Fermi resonance effects. The former torsional/bending ring vibrations also exhibit potential-dependent frequencies (i.e., an electrochemical Stark effect), reflecting copper−triazole electronic interactions. Taken together, the SER spectral features for BTAH and BTA- suggest surface attachment via a pair of triazole nitrogens with a tilted (or vertical) orientation; the single nitrogen binding site anticipated for BTAH2+ is consistent with the milder vibrational perturbations observed for this adsorbate. The transformation from adsorbed benzotriazole to a CuIBTA film at higher potentials is readily diagnosed from the SER spectra, including the observed lack of a D/H vibrational effect on the latter species. The structure of benzotriazole films in air is also examined; emersion of adsorbed BTAH from solution spontaneously yields a CuIBTA layer via a coupled O2-induced electrochemical pathway. The thermal stability of copper-benzotriazole films in ambient-pressure O2 and N2 from 25 to 300 °C was also probed with SERS.

Corrosion inhibition of steel by benzotriazole in sulphuric acid

The corrosion behaviour of low-carbon steel in different concentrations (10 −3 to 9 × 10 −3 M) of benzotriazole (BTA) in 1 M H 2SO 4 has been studied by potentiodynamic polarization measurements at a scan rate of 0.166 mV s −1. It is found that passivation current, corrosion potential, passive potential and polarization resistance increase with increasing benzotriazole concentrations, while critical current, corrosion current and corrosion rate decrease. It is established that the corrosion rate depends on the concentration of the inhibitor and chloride ions along with the sweep rate of polarization. A maximum inhibition efficiency (98.5%) was obtained at 9 × 10 −4 M BTA. Thermodynamic parameters for adsorption of BTA are calculated.

Benzotriazole Adsorption and Inhibition of Cu(100) Corrosion in HCl: A Combined in Situ STM and in Situ FTIR Spectroscopy Study

The adsorption and the corrosion inhibiting effect of benzotriazole (BTAH) on Cu(100) electrodes in 0.1 M HCl were investigated using in situ STM, in situ FTIR spectroscopy, and electrochemical measurements. In the double-layer range up to potentials of −0.6 V vs SCE a Cu surface morphology with extended, atomically flat terraces, separated by almost randomly oriented steps, and a low Cu surface mobility are observed by STM. High-resolution STM images reveal a commensurate superstructure in this potential range, which is attributed to a chemisorbed adlayer of BTAH molecules. At potentials around −0.6 V this structure is replaced by a c(2 × 2) Cl- adlayer, which has the same atomic and long-range structure as found in BTAH-free HCl solution. Upon further potential increase to potentials >−0.35 V STM experiments and polarization measurements indicate the onset of Cu dissolution, while the surface is still covered by the c(2 × 2) Cl- adlayer. At slightly higher potentials (>−0.3 V) STM, IR, and electrochemic...

The adsorption properties of NaY zeolite for separation of aromatic triazoles

The zeolite molecular sieve Na-Y was investigated for its ability to separate benzotriazole (BTZ) from tolyltriazole (TTZ). The method used was a liquid phase slurry where activated zeolite was added to a solvent mixture containing the components to be separated. The liquid samples were analysed by FTIR spectroscopy before and after the adsorption to determine the uptake of the components. The zeolite was shown to adsorb both the additives BTZ and TTZ. The solvent effects on the adsorption of BTZ were investigated showing that maximum uptake was achieved using diisopropyl ether, in preference to isobutyl acetate or 2,6 dimethylheptan-4-one. Increasing the experimental temperature indicated that the uptake of BTZ could be increased in the solvents isobutyl acetate and 2,6-dimethylheptan-4-one. It was shown that BTZ was preferentially adsorbed to TTZ, from mixtures of the two with a selectivity of the order of two.

Adsorption and film growth of BTA on clean and oxygen adsorbed Cu(110) surfaces

Benzotriazole (BTA) adsorption on clean Cu(110) and oxygen reconstructed Cu(110)−2 × 1 and c(6 × 2) surfaces has been investigated by scanning tunneling microscopy (STM). The STM images show that BTA forms the c(4 × 2) commensurate phase on the clean Cu(110)−1 × 1 surface. On the other hand, STM images of BTA adsorbed on the oxygen-induced Cu(110)−2 × 1 surface show a fully disordered structure. From a kinetic point of view, BTA molecules should adsorb preferentially on the oxygen-induced Cu(110)−2 × 1 added row compared to the clean Cu(110) surface.

The role of benzotriazole in corrosion inhibition: formation of an oriented monolayer on Cu 2O

Studies of the adsorption of benzotriazole (BTAH) on Cu 2O surfaces have been carried out up to saturation coverage using both experimental (transmission UV and Auger electron spectroscopy (AES)) and computational approaches. Correlation of the UV integrated band intensity for the adsorbed BTA − species with quantitative measurements of N/Cu ratios from AES shows the saturation coverage of chemisorbed BTA − to be Γ ML ≈ 6.3 × 10 14 cm −2. Calculations based on a molecular mechanics (MM2) minimization of the BTA − structure show a maximum surface density of 8.3 × 10 14 and 2.4 × 10 14 cm −2 for orientations in which the BTA − plane is perpendicular and parallel to the surface, respectively, thereby indicating that BTA − cannot be bound with the ring plane parallel to the surface under these conditions. Furthermore, the orientation is invariant with surface density, as demonstrated by coverage-dependent dichroic ratio measurements. Semi-empirical calculations of free BTA − and transmission linear dichroism measurements suggest that an orientation in which the ring plane is perpendicular to the surface with the C 2 axis canted away from the surface normal is the most reasonable proposal for the structure of the adsorbed layer.

The role of nitrogen and sulfur heterocycles in corrosion inhibition. 1. Initial steps in the adsorption of benzotriazole at copper(I) and copper(II) oxides

The role of nitrogen and sulfur heterocycles in corrosion inhibition. 1. Initial steps in the adsorption of benzotriazole at copper(I) and copper(II) oxides

A comparative study of the inhibition effects of benzotriazole and 6-aniline-1,3,5-triazine-2,4-dithiol monosodium salt on the corrosion of copper by potentiodynamic polarization, AC impedance and surface-enhanced Raman spectroscopic techniques

The inhibition effects of benzotriazole (BTA) and 6-aniline-1,3,5-triazine-2,4-dithiol (ATD) monosodium salt on copper corrosion have been studied by the potentiodynamic polarization, AC impedance and surface-enhanced Raman spectroscopic techniques. The polarization resistance R p increases with the concentration of either BTA or ATD. From the plots of the phase shift θ versus logarithm of the frequency, it is found that θ is close to 90° after the copper electrode is immersed for a long period of time in BTA-containing solution which indicates the behavior of an ideal capacitor. In ATD-containing solutions, θ is close to 45 ° which shows the appearance of a Warburg impedance for a diffusion process. Surface-enhanced Raman spectroscopic studies of the competitive adsorption of BTA and ATD on copper surfaces indicate that BTA adsorbs better than ATD. Based on these results, it is concluded that the inhibition action of BTA is better than that of ATD.

Near-infrared Fourier transform surface-enhanced Raman scattering of azole copper corrosion inhibitors in aqueous chloride media

This work reports on the application of near-infrared Fourier transform surface-enhanced Raman scattering (FT-SERS) in the study of competitive adsorption of benzotriazole and tolyltriazole on copper electrodes. This technique has also been extended to investigate the inhibitors present in commercial anti-freeze. The results obtained show that there is co-adsorption and that benzotriazole displaces tolyltriazole when its concentration is increased.

Sers and impedance study of the equilibrium between complex formation and adsorption of benzotriazole and 4-hydroxybenzotriazole on a copper electrode in sulphate solutions

Abstract The corrosion inhibition mechanism of benzotriazole and 4-hydroxybenzotriazole for copper in sulphate solutions was investigated by SERS spectroscopy and impedance measurements. These inhibitors form complex polymers on the copper surface at high pH of the solution, positive potential of the electrode, and high concentration of the inhibitors. At low solution pH, negative electrode potential and low inhibitor concentration, single molecules of the inhibitors are adsorbed chemically on copper. Equilibrium between the complex formation and the adsorption relates strongly with the corrosion inhibition effect. 4-Hydroxybenzotriazole shows a higher inhibition efficiency at the high solution pH than benzotriazole, at low pH values this order is reversed.

X-ray photoelectron spectroscopy and ellipsometry studies of the electrochemically controlled adsorption of benzotriazole on copper surfaces

Adsorption of the corrosion inhibitor benzotriazole (BTA) from solution has been studied on well-characterized electrochemically prepared Cu surfaces. In situ ellipsometry and ex situ x-ray photoelectron spectroscopy (XPS) have been used to probe both the nature of the Cu surfaces prior to BTA adsorption and to determine the stoichiometry, thickness, and chemical composition of the Cu–BTA overlayer films. The films grown on Cu2O and on Cu0 under oxidizing conditions are generally 5–40 Å thick and best described as Cu+1 BTA. Uptake of BTA is also observed on CuO and reduced Cu0 surfaces where the adsorbed film is limited at close to a monolayer. Therefore, Cu2O does not appear to be a prerequisite for uptake of BTA. The thickness of the inhibitor overlayer was calculated from the N 1s/ Cu 3p core level XPS data and was in good agreement with independent ellipsometric measurements on similar samples. Roughening of the Cu surface is observed for samples treated at low pH. Differing amounts of oxygen are found in the Cu+1 BTA films depending upon the preparation environment.

Summary Abstract: The adsorption of benzotriazole on copper and cuprous oxide

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Adsorption Isotherm for the Copper-Benzotnazole System

An appropriate adsorption isotherm for the adsorption of benzotriazole on to copper surfaces from ammonium chloride solutions is presented. The analysis, which has taken into account the relative size factor, leads to the appropriate isotherm being that due to Frumkin. Some thermodynamic parameters of the adsorption isotherm are thus evaluated.

Adsorbed corrosion inhibitors studied by electron spectroscopy: Benzotriazole on copper and copper alloys

Surface films formed by adsorption of benzotriazole (BTA), on copper and copper alloys have been studied by X-ray photo-electron spectroscopy (XPS). It is found that on both copper and copper-nickel alloys, benzotriazole forms a Cu(I)BTA surface complex. For the copper-nickel alloys the time taken to form the Cu(I)BTA film is dependent on the alloy composition. The Cu(I)BTA films were found to oxidize rapidly to a Cu(II) species on removal from the liquid phase. Surface films formed by BTA on 70 Cu : 30 Zn alloy were found to contain both copper and zinc, the copper again being in the Cu(I) state. A study of the adsorption of BTA on cathodically reduced copper surfaces strongly supports previous suggestions that the presence of Cu 3O facilitates formation of the surface film.

Benzotriazole adsorption on copper studied by X-ray photoelectron spectroscopy

Benzotriazole adsorption on copper studied by X-ray photoelectron spectroscopy

ベンゾトリアゾールの防錆作用に及ぼす水溶性有機硫化物の効果

The effects of water-soluble organic sulfides on the inhibitive effect of benzotriazole for iron were studied. In this paper, sodium dimethyl dithiocarbamate, sodium diethyl dithiocarbamate and sodium dibuthyl dithiocarbamate were used as water-soluble organic sulfides. The inhibitive properties of benzotriazole were determined by measuring the weight loss of iron specimens as usual. By sulfide treatment of iron, that is, putting the iron specimens in sulfide solutions, the inhibitive properties of benzotriazole on iron in neutral solutions were increased and the velocity of dissolution of iron in acid solution was increased. It was shown in earlier paper that the change of potential of iron in benzotriazole solution was agreed to Langmuir's adsorption formula, expressed as follows: x=kk1C/(1+kC), where x is the amount of substances adsorbed per unit area at concentration C, and k and k1 are constants, supposing that the change of potential is in proportion to x as Uhlig and Geary had reported. So the changes of k and k1 by sulfide treatment were studied. As the result, it was recognized that the larger the constants k and k1 are, the more the inhibitive properties of benzotriazole increase. Therefore, it was thought that the surface of iron was activated by sulfide treatment and then the adsorption of benzotriazole on the surface of iron became easy.NMR spectra of each sulfide solutions weree measured and it was found that there was a linear relation between the chemical shift of the nearest proton of N atom and the inhibitive properties of benzotriazole corresponding to each sulfide treatments.