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In order to optimize the potential (U) to allow the synthesis of Cu3BiS3 (CBS) thin films by co-electrodeposition, the synthesized samples on fluorine-doped tin oxide (FTO) were sulfurized and then analyzed by many techniques. For U = −0.95 V, x-ray diffraction (XRD) shows the major presence of Cu3BiS3 characteristic peaks at 31.27°, 28.99°, and 34.81° as well as the main peak at 280 cm−1 in their Raman spectra. However, the potential decrease to U = −1.05 V introduced a broadening of the main peaks on the two XRD and Raman spectra. With regard to the morphology, scanning electron microscopy (SEM) mapping analysis shows a well-defined grain shape for U = −0.95 V, which varies with the variation in U. In addition, the UV–visible spectrum indicates that the optical band gap decreases from 1.44 eV to 1.33 eV when the potential U varies from −1.050 V to −0.950 V. The CBS semiconductor nature was also highlighted by the theoretical DFT calculations in the generalized gradient approximation with modified Becke–Johnson (GGA + mbJ) condition. This theoretical enrichment confirms that the CBS optical band gap is about 1.42–1.52 eV, which is comparable to that of the experimental study. [ABSTRACT FROM AUTHOR]

The optimization of the factors influencing the co-electrodeposition method makes it extremely efficient in the production of thin films formed by multiple elements. This work presents the synthesis of Cu2CoSnS4 (CCTS) thin films by the simultaneous electrodeposition of Co, Sn, Cu, and S elements on the FTO substrate using tartaric acid (HT) as a complexing agent. To study the influence of copper concentration on the physicochemical properties of CCTS, these films were deposited at a co-electrodeposition potential of − 900 mV for concentrations [Cu2+] ranging from 0.015 to 0.030 M (vs. saturated calomel electrode (SCE)). After a sulfurization step in a quartz tube at 500 °C under an argon flow for one hour, the samples formed are analyzed by different techniques: X-ray diffraction technique showing characteristic peaks relating to planes (112), (204), (312) (400), and (004) of the CCTS phase, as well as the characteristic peaks located at 290 cm−1 and 325 cm−1 with Raman spectroscopy, and then the effect of copper concentration on the optical properties was identified by UV–Visible spectrophotometry which showed that the optical-gap values are decreased from 1.68 to 1.48 eV when the Cu concentration was varied from 0.015 to 0.030 M. [ABSTRACT FROM AUTHOR]

The performance of clay purified and intercalated with Ca2+ against Nicrofer 3127 alloy corrosion in hydrodynamics conditions was evaluated utilizing electrochemical techniques, weight loss method, and surface analysis. The characterization technique has shown that the clay tested is the montmorillonite type. Purified montmorillonite and Ca2+-montmorillonite act as an effective corrosion inhibitor of the Nicrofer 3127 alloy under hydrodynamic conditions at an optimal concentration of 4.0 g/L and 1.0 g/L, respectively. The purpose of intercalating the clay with Ca2+ is to improve the adsorption of aggressive agents and to use low concentrations. The better inhibition efficiency for clay intercalated with Ca2+ was obtained 75% (based on EIS results) at 1.0 g/L. After 6 h of immersion under hydrodynamic conditions, the inhibitory efficiency of montmorillonite-Ca2+ was reached a value of 89%. This behavior can be attributed to the formation of calcium phosphate Ca3(PO4)2 on the surface of the Nicrofer 3127 alloy. [ABSTRACT FROM AUTHOR]

The inhibition capacity of carbon steel (CS) in 0.5M H2SO4 by three 8-hydroxyquinoline grafted triazole derivatives (EHTC, AHTC, and MHTC) have been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PPD), and weight loss measurements (WLM) at 298 K. Generally, the results clearly show that the inhibition performance (η %) increases with an increase in the concentration of EHTC, MHTC, and AHTC, reaching a maximum value of 95.5% (EHTC), 95.1% (MHTC), and 94.1% (AHTC) at the optimal concentration (10−3 M) for PPD technical. The PPD shows that EHTC, AHTC, and MHTC behave as mixed-type inhibitors. In addition, the inhibitor obeys the single layer adsorption isotherm of Langmuir. Scanning electron microscopy (SEM) analysis of the CS has also been investigated and discussed. The theoretical calculations and MD simulations show a better correlation with the experimental results for the studied triazole derivatives. [ABSTRACT FROM AUTHOR]

Two imidazopyridine derivatives 6-chloro-2-(4-chlorophenyl) imidazo [1,2-a]pyridine (IPCl1) and 6-chloro-2-(4-chlorophenyl)imidazo[1,2-a]pyridine-3-carbal-dehyde (IPCl2) were investigated as corrosion inhibitors of mild steel in 1.0M HCl medium using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The concentrations used in this work ranged between 1.0 × 10–6 and 1.0 × 10–3 M. Those compounds were found to be good inhibitors. In addition, their adsorption on the mild steel surface obeyed the Langmuir adsorption isotherm. A quantum chemical calculation was computed using Gaussian 09 based on the density-functional theory method at B3LYP/6-31G (d, p) in order to relate some electronic properties of the studied compounds to the inhibition efficiencies achieved experimentally. The Fukui functions were calculated to estimate the most reactive sites of nucleophilic and electrophilic attacks. Finally, the molecular dynamics simulation was implemented to search for the equilibrium configurations of IPCl1 and IPCl2/Fe(110) adsorption systems in a hydrochloric acid solution at various temperatures. The theoretical and experimental results obtained were in good correlation. [ABSTRACT FROM AUTHOR]

The inhibiting effect of benzimidazole derivate (DBI) on corrosion of carbon steel (CS) at temperature range of 303–333 K was investigated in hydrochloric acid by DC potential dynamic polarization and AC electrochemical impedance spectroscopy. It was found that this compound behaved as a mixed-type inhibitor with predominantly cathodic effect. The EIS results indicate that the inhibition efficiency increases with increasing the inhibitor concentration and the maximum inhibition (%) was obtained in the presence of 10−3 M of DBI. The adsorption of DBI on the carbon steel surface is described by the Langmuir adsorption isotherm and had a physical and chemical mechanism. The results found experimentally were corroborated by DFT-quantum chemical calculations and molecular dynamics simulations (MDS) methods. [ABSTRACT FROM AUTHOR]

Quaternary semiconductor Cu2NiSnS4 (CNTS) has emerged as an ideal material for solar cells and has attracted the attention of researchers. Tetragonal-structured CNTS thin films have been successfully synthesized via sulfurization (500°C, argon + sulfur) of co-electrodeposited Cu-Sn-Ni-S precursors on molybdenum (Mo) substrate. The effects of the Ni2+ molarity on the deposition potential, structure, composition, morphology, and optical bandgap of the CNTS thin film were examined by using cyclic voltammetry, Raman spectroscopy, x-ray diffraction analysis, scanning electron microscopy (SEM), energy-dispersive x-ray (EDX) spectrometry, and ultraviolet–visible (UV–Vis) spectrophotometer. X-ray diffraction and Raman analyses confirmed formation of CNTS with tetragonal structure and average crystallite size of 17 nm to 20 nm. SEM revealed that the films were homogeneous, while EDX confirmed the presence of Cu-Ni-Sn-S, and the bandgap of the CNTS thin films was evaluated to lie in the range of 1.6 eV to 1.8 eV, making CNTS a strong candidate material for use in photovoltaic cells. [ABSTRACT FROM AUTHOR]

New benzodiazepine derivatives, namely 8-Chloro-1,2,3,4,10,11-hyxahydrospiro[cyclohexane-1,11-dibenzo[1,4]diazipine] and 8-methyl-1,2,3,4,10,11-hyxahydrospiro[cyclohexane-1,11 dibenzo[1,4]diazipine] are heterocyclic and their inhibitive action against the corrosion of carbon steel in 1.0 M HCl solution was studied at 303 K by electrochemical impedance spectroscopy and polarization curves The results marked that the learned benzodiazepine product are good corrosion inhibitors to carbon steel in 1.0 M HCl medium, their inhibition efficiency increased with inhibitor concentration, and BND–Cl is slightly more effective than BND–CH3. Potentiostatic polarization study showed that BND–CH3 and BND–Cl are mixed-type inhibitors in 1.0 M HCl. Impedance experimental data disclose a frequency distribution of the capacitance, simulated as a constant phase element. The results obtained from electrochemical studies were in reasonable accordance. The adsorption of BND–Cl and BND–CH3 on steel surface obeyed Langmuir's adsorption isotherm. Thermodynamic data clearly proper that the adsorption mechanism of benzodiazepine products on carbon steel surface in 1.0 M HCl solution is physical adsorption which implies electrostatic forces among the electric charge or ionic charges at metal/solution interface and dipoles of the adsorbent verify by the a chemisorption. Quantum chemical calculations employ the Density Functional Theory (DFT) were performed on benzodiazepine products to define the link between molecular structures and their inhibition efficiencies. Furthermore, the structures mentioned are stimulated by the Monte Carlo simulation to comprehend the adsorption mechanism. Finally, the correlation among experimental and theoretical returns was discussed. [ABSTRACT FROM AUTHOR]

Quaternary compound Cu2CoSnS4 (CCTS) is a potential candidate absorber layer in thin film solar cells to produce clean and inexhaustible energy. In this work the Cu2CoSnS4 (CCTS) thin film was synthesized for the first time by co-electrodeposition of Cu–Co–Sn–S precursors on Molybdenum substrate, followed by a high temperature (500 °C) sulfurization under Argon atmosphere. The potential deposition (−0.95 V/SCE) was determined from cyclic voltammetry. The structure, composition and morphology of the CCTS thin film is characterized in detail by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and energy dispersion spectroscopy. The p-type conductivity of CCTS thin film was confirmed using Mott–Schottky analysis and the band gap value was evaluated to be 1.56 eV, which makes CCTS a promising material for solar cell applications. [ABSTRACT FROM AUTHOR]

The effect of adding 2-phenylimidazo[1,2-a]pyridine-3-carbaldehyde derivative named (P2), newly synthesized on the electrochemical behavior of C38 steel in molar hydrochloric acid was investigated by using the weight-loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) measurements. EIS results show that the transfer resistance increases with the increase of concentration of P2 and it also had an inhibiting effect on C38 steel corrosion in HCl solutions. Weight-loss essays confirm that the corrosion rate decreases as the P2 concentration increases. The inhibition efficiency for this compound studied increased with the increase in the inhibitor concentrations to attain 91.7 % at the 10 M of P2. The potentiodynamic polarization curves indicated that P2 acted as a mixed-type inhibitor in hydrochloric acid. [ABSTRACT FROM AUTHOR]

new corrosion inhibitor, viz. 3-ethyl-6-méthyl-quinoxalin-2-one, 1-benzyl-6-methyl-quinoxalin-2-one, 2-benzyloxy-3,6-dimethyl-quinoxaline, 1-benzyl-3-methyl-quinoxalin-2-one, were synthesized in the laboratory. Their influence on the inhibition on corrosion of bronze in aqueous chloride solution (3% NaCl) was studied by electrochemical polarization methods and weight-loss measurements. The impact of temperature on the effectiveness of the substances mentioned above has been determined between 20 and 60°C. The results showed that the corrosion resistance was greatly enhanced in the presence of inhibitor and that the effectiveness depends on some physicochemical properties of the molecule, related to its functional groups. These compounds act through the formation of a protective film on the surface of the alloy. [ABSTRACT FROM AUTHOR]