International Journal of Electrochemical Science最新文献

In this paper, Bismuth/poly(3,4-ethylenedioxythiophene) (Bi/PEDOT) modified electrochemical modified electrodes were prepared by electrochemical deposition method, and the electrochemical performance of the electrode was investigated using cyclic voltammetry under the optimal experimental conditions. The PEDOT polymer has high conductivity, and bismuth can form an alloy with cadmium ions. Bi/PEDOT nanocomposite materials have a larger specific surface area and more active sites, which is more conducive to absorbing more cadmium ions (Cd²⁺). The Differential pulse anodic stripping voltammetry method was used to study the electroanalytical performance of the sensor for Cd²⁺. The data show that the oxidation peak current of cadmium ions in the Bi/PEDOT modified electrode is significantly higher than that of other electrodes, due to the synergistic effect of the composite conductive materials. In the concentration range of 1 nM-40 μM, the concentration of cadmium ions shows a good linear relationship with the peak current, and the lowest detection limit is 0.33 nM. In addition, the sensor also exhibits good stability, reproducibility and very low detection limit, which can be used for rapid determination of trace cadmium ions, with a recovery rate in actual sample analysis of 101.4 %-104.0 %.

Neutral electrolyte, such as synthetic seawater (SW), is a promising candidate for aluminum-air (Al-air) battery due to the alleviated hydrogen evolution along with anode self-corrosion. However, aluminum surface passivation in SW poses a serious challenge for battery's power generation. Following molecular self-assembly theory, 5-carboxylate benzotriazole (CB) was incorporated into β-cyclodextrin (β-CD), which (CB@β-CD) was utilized as an interfacial activator for aluminum anode in SW. CB could be released from β-CD, and activated aluminum surface, facilitating anode discharge. The specific capacity and energy density of Al-air battery were achieved as 2607.4 mAh/g_Al and 2.37 kWh/kg_Al, respectively, at an optimal CB@β-CD concentration of 120 mg/L. Density functional theory calculations revealed that the overwhelming adsorption energy of guest molecule (CB) on Al (111) plane over its binding energy inside host (β-CD) accounted for the release of CB on anode surface, and the ensuing interfacial activation effect.

Carbon materials, as the skeleton structure of electrode materials, are composited with lithium-ion anode materials, which not only increase the electrical conductivity of the materials, but also enhance the electrochemical performance of the electrode materials. In this paper, LiV₃O₈@C composites were prepared by using coconut shell-based porous carbon to structurally modulate aqueous lithium-ion anode materials. And three composites with different structures and sizes were successfully synthesized by hydrothermal method, hydrothermal stirring method and improved solid-phase method. After XRD and SEM analyses, it was found that all three composites maintained the monoclinic crystal system structure of LiV₃O₈, and the materials prepared by the hydrothermal method showed a smooth layer structure, while the materials prepared by the hydrothermal stirring method and the solid-phase method showed nanorods with different sizes. The prepared anode materials and LiFePO₄ cathode materials were assembled into an aqueous lithium-ion full battery, and were subjected to charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that the electrochemical performances of the three composites are significantly improved compared with the pure LiV₃O₈. Specifically, the discharge capacities of the two groups of nanorod-like composites were 112.2 mAh/g and 85.5 mAh/g at a rate of 0.2 C, which were improved by as much as two times compared with the pure LiV₃O₈. However, the composite material with layered structure not only reaches an initial discharge specific capacity of 148.39 mAh/g, which is 2.7 times higher than that of the pure LiV₃O₈, but also effectively slows down the dissolution effect of LiV₃O₈ by compositing with the carbon material, and at the same time, it shows excellent rate performance.

To investigate the influence of different crystal orientations of tantalum on corrosion performance, this study explored the diverse corrosion behaviors exhibited by the (110), (200), and (211) crystal planes of monocrystalline tantalum in a 3.5 wt% NaCl aqueous solution. The electrochemical behavior of the three crystal planes was characterized using open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy tests. The results revealed that the corrosion potential of the (110) crystal plane was slightly higher than that of the other two crystal planes, suggesting that this can be attributed to the influence of surface energy. The corrosion current density and corrosion rate of the (110) crystal plane were measured to be 0.269 μA cm⁻² and 1.911 × 10⁻³ mm/y, respectively, significantly exceeding those of the other two crystal planes. Additionally, the electrochemical impedance spectroscopy results indicated that the modulus impedance and polarization resistance of the (110) crystal plane were much lower compared to the other two crystal planes, suggesting inferior corrosion resistance. A comprehensive analysis indicates that the (110) crystal plane exhibits poorer corrosion resistance compared to the (200) and (211) planes, with the interplanar spacing identified as the primary factor influencing its corrosion resistance.

This study investigates the electrochemical properties of quinine hydrochloride (QH) using boron-doped diamond (BDD) electrodes. The redox behavior of QH was analyzed and compared in phosphate buffer solution (PBS) and potassium perchlorate (KClO₄) electrolyte, observing an increase in current response with hydrogen-terminated BDD (H-BDD) electrodes. A cyclic voltammogram of QH in 0.1 M PBS and 0.1 M KClO₄ shows a reduction peak at −1.14 V (vs. Ag/AgCl). The scan rate dependence was examined to understand the reduction mechanism involving two electrons. A linear calibration curve was noted from 2 μM to 25 μM range (R² = 0.99) with detection limits of 0.18 μM in PBS and 0.16 μM in KClO₄. The BDD electrodes demonstrated good selectivity in tonic water with sharp oxidation potentials for QH, confirming their stability for QH detection.

The corrosion inhibition behavior of cetyl pyridinium chloride (CPC) on mild steel (MS) in 0.5 M H₂SO₄ solution was examined using weight loss and potentiodynamic polarization method. Different concentrations of CPC (0.000192 M, 0.0038 M, 0.0057 M and 0.0077 M) was used to find the balanced CPC in the acid solution. Among them, 0.000192 M and 0.0077 M of CPC solution showed a corrosion rate of 8.23×10⁻³, 3.52×10⁻⁵ (mm/Year), and the inhibition efficiency of 89.94 % and 96.23 %, respectively, which is lower than the pure acidic solution (0.5 M H₂SO₄). Furthermore, the experimented MS surfaces were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Atomic Force Microscopy (AFM). FESEM and AFM studies demonstrated the corrosion attack on the MS surface, which is relatively less as compared to the only acid-exposed surface. The SEM-EDX analysis indicates the presence of nitro-group on the MS surface, which might be due to the contribution of pyridinium protonation of CPC. This phenomenon might enhance the corrosion resistance on the MS surface.

Corrosion poses a significant threat to the integrity and longevity of iron and its alloys, which are crucial materials for modern industry and infrastructure. This study investigates the effectiveness of two recently synthesized inhibitors based on quinoline structures: MPQ (2-methyl-5-(propoxymethyl) quinolin-8-ol) and AAQ ((((2-aminoethyl)amino)methyl)-2-methylquinolin-8-ol) in protecting steel against environmental degradation, particularly in acidic and chloride-rich conditions such as hydrochloric acid. The inhibitors exhibited significant corrosion inhibition efficiencies of 92.37 % for MPQ and 84.13 % for AAQ, as demonstrated through electrochemical analysis. Surface characterization techniques, including SEM-EDX(Scanning Electron Microscopy with Energy Dispersive X-ray analysis), AFM (Atomic Force Microscopy), and contact angle measurements, revealed the formation of a protective barrier film that reduces the corrosion rate. Additionally, theoretical calculations using the Gaussian package provided insights into the adsorption behaviors and protective mechanisms of the inhibitors on mild steel surfaces. The findings contribute to the ongoing search for viable corrosion inhibitors, offering prospects for application in industries and critical infrastructures to enhance corrosion protection and durability.

Here, we report the synthesis of hard carbon materials (CSHs) made from corn starch and their application as an anode in lithium-ion batteries. The study shows that the microstructure and electrochemical properties of CSHs are affected by nitrogen doping. It is found that nitrogen is embedded in the carbon layer with graphite nitrogen, pyridyl nitrogen, and pyrrole nitrogen, so that the surface morphology was changed and reduced the disorder of the materials. The electrochemical test results show that the introduction of nitrogen elements can increase the reversible capacity of the material, with the first discharge capacity reaching above 426.35 mAh g⁻¹, and the rate performance also improves. When melamine and pre-carbonized corn starch are carbonized at a mass ratio of 1:9, the obtained material has a reversible capacity of 122.04 mAh g⁻¹ at a rate of 2 C. During the carbonization process, the nitrogen in melamine is doped into the carbon materials, improving the electrochemical performance of the material.

The present study is concerned with the corrosion inhibition and adsorption behaviour of a series of novel imidazole derivatives. The compounds under investigation are 5,5-diphenyl-3-propyl-2-(propylthio)-3,5-dihydro-4 H-imidazol-4-one (AM3) and 3-allyl-2-(allylthio)-5,5-diphenyl-3,5-dihydro-4 H-imidazol-4-one (AM6). The objective of this study is to evaluate the efficacy of 5,5-diphenyl-3,5-dihydro-4 H-imidazol-4-one (AM6) as a corrosion inhibitor on mild steel immersed in a 1.0 M hydrochloric acid medium. This comprehensive study assesses the efficacy of these derivatives through a range of electrochemical and spectroscopic analysis techniques. Additionally, polarisation curves, electrochemical impedance spectroscopy and advanced computer simulations were employed to evaluate the efficacy and inhibition mechanism of imidazole derivatives, thereby facilitating a more profound understanding of their anticorrosive capacity. The results obtained from potentiodynamic polarisation (PDP), electrochemical frequency modulation (EFM) and electrochemical impedance spectroscopy (EIS) measurements demonstrate that the inhibition efficiency increases with increasing imidazole derivative concentration. Conversely, an inverse relationship is observed between inhibition efficiency and temperature. The thermodynamic parameters ΔG°_ads and ΔH°_ads corroborate the conclusion that the adsorption process is predominantly chemical in nature. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) were employed to characterise the surface morphology. The maximum protection afforded by imidazole derivatives was 95.2 % and 93 % for compounds AM3 and AM6, respectively. Polarisation curves indicated that imidazole derivatives exhibited mixed inhibition behaviour. Surface analysis demonstrated that imidazole derivatives were effectively adsorbed onto the carbon surface, thereby significantly reducing acid damage. This finding was corroborated by DFT calculations, as well as Monte Carlo (MC) and molecular dynamics (MD) simulations. These simulations provided a comprehensive insight into the adsorption of imidazole and its protonated form onto the carbon surface, offering valuable insight into the corrosion inhibition mechanism.