Journal of Solid State Electrochemistry最新文献

In this work, a three-component catalyst PdCu/Ag is synthesized using the partial galvanic displacement of copper by silver from the PdCu deposit (~24 at.% Cu) prepared using the electrochemical co-deposition of Pd and Cu (Au support, 0.5 M H₂SO₄). The composite is characterized by a variety of methods. It is shown that during the galvanic displacement, both Cu and Pd are displaced by silver. The PdCu/Ag catalyst demonstrates higher specific (~twofold) and mass activity (~70-fold) in the reaction of formic acid electrooxidation (FAOR) as compared with individual Pd deposits. The possible factors responsible for the higher Pd activity in the presence of both incorporated Cu and Ag are discussed.

In the present study, the hydrothermal method has been used for the synthesis of a manganese dioxide/nitrogen-doped reduced graphene oxide (α-MnO₂/N-rGO) composite. The physical–chemical properties of the synthesized α-MnO₂/N-rGO were examined by different techniques such as powder X-ray diffractometer (XRD), energy dispersive X-ray analysis (EDX), and scanning electron microscopy (SEM). The synthesized α-MnO₂/N-rGO was further used as the catalyst towards the fabrication of a hydrazine (Hz) sensor. The screen-printed carbon (SPC) electrode was modified with α-MnO₂/N-rGO via the drop-cast method. Linear sweep voltammetry (LSV) was used for the determination of Hz, and observations showed that the α-MnO₂/N-rGO/SPC electrode has decent performance in terms of sensitivity, detection limit, and selectivity. The detection limit of 0.08 µM and sensitivity of 2.47 µA/µM.cm² were obtained using this modified electrode.

Bipolar electrode corrosion (BPEC), utilizing bipolar electrochemistry, has emerged as a pivotal technique in corrosion research by leveraging potential gradients between two feeder electrodes immersed in electrolyte solutions. This review provides a comprehensive exploration of the methodology, applications, and underlying corrosion mechanisms associated with BPEC, emphasizing its versatility across diverse domains. By establishing an electric field gradient, BPEC facilitates simultaneous oxidation and reduction reactions across a wide electrochemical potential range, typically inducing oxidation near to the negative feeder electrode and reduction adjacent to the positive electrode. The straightforward setup allows efficient screening of corrosion behavior under varied conditions, offering insights into anodic-to-cathodic corrosion dynamics on individual electrodes. Application of BPEC to steel samples reveals insights into pitting, crevice corrosion, general corrosion, and passive behavior, enabling thorough assessment of corrosion phenomena. Integration with sample arrays accelerates comparative studies, while analysis of local current and potential distributions enhances methodological understanding. This review underscores BPEC’s capability for spectroscopic, quantitative, and qualitative assessment of multiple samples in galvanic corrosion studies, providing a streamlined approach to evaluate comparative corrosion behavior within a single experiment. Moreover, evaluating pitting morphology on anodic surfaces offers a straightforward method for quantifying and qualitatively assessing overall corrosion performance across diverse sample sets.

Nanocrystalline TiO₂ nanotube electrodes were fabricated by electrochemically anodizing the titanium in the electrolyte with an ethylene glycol with addition of 0.5% by weight NH₄F and amount of water (2% w/w). Structural properties of the obtained coatings have been investigated by scanning electron microscopy and Raman and XRD spectroscopy. When illuminated by a sunlight simulator, these electrodes demonstrate high activity in photoelectrochemical degradation of anions of phenylacetic acid from aqueous solutions of 0.1 M Na₂SO₄. Results of intensity-modulated photocurrent spectroscopy show that the photoelectrocatalysis efficiency is explained by suppression of the electron–hole pair recombination and increase in the rate of photo-induced charge transfer. Thus, nanotubes from TiO₂ can be considered as effective photoanodes.

Two-dimensional (2D) materials have been widely used in lithium-ion batteries (LIBs) because of their excellent properties. In this paper, the electrochemical properties of Li₃CrMnO₄, a new 2D material used as cathode material for LIBs, were studied by using the first-principles calculations. The results show that the theoretical capacity of the material is as high as 419 mAh/g, which is a rather superior capacity value, indicating that the study of Li₃CrMnO₄ material has important practical significance. The voltage platform, structure evolution, and charge compensation mechanism of the material in the delithiation process are discussed. The calculation results suggest that the transition metal ions in the material have good chemical activity, capable of fulfilling the charge compensation for complete delithiation. In the whole process of Li extraction, the material has good structural stability and can maintain the layered structure. The maximum charging voltage of the material is 4.26 V. However, the delithiation process reveals multiple voltage platforms, and the stability of the operating voltage is relatively poor.

Wire electrical discharge machining (WEDM) of the Ti6A14V alloy surface generates a recast layer and microcracks, which seriously affects the strength and corrosion resistance of the parts. Electrochemical polishing is widely used in metal surface finishing due to its low cost and high efficiency. To solve the problem of surface quality after WEDM machining, in this paper, electrochemical polishing of Ti6Al4V alloy after machining is investigated for different ethanol/glycol ratios of polishing solution and surface corrosion resistance. Based on this study, the effect of current density on the surface roughness, morphology, and corrosion resistance of WEDM-machined parts was also analyzed. By optimizing the ethanol/glycol ratio and current density, a micron-sized impurity-free Ti6Al4V surface was obtained at a glycol/ethanol ratio of 4:1 and a current density of 0.55 A cm⁻², and the surface roughness (Ra) was reduced from 3.69 to 0.40 μm. The microcracks and recast layer were completely removed, the corrosion current density was reduced by one order of magnitude, and the corrosion resistance was significantly improved, which amounted to 0.49 ± 0.04 µA cm⁻².

The ITO/TiO₂NTs/AgNPs–dye photoanode, with potential applicability for dye-sensitized solar cells (DSSCs), was characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission gun scanning electron microscopy (FEG-SEM), and diffuse reflectance spectroscopy (DRS). XRD analysis and Raman spectra confirmed the presence of the anatase phase of TiO₂NTs, while Raman also identified the presence of the grape skin extract (“dye”) on the surface of the film. FEG-SEM images revealed TiO₂NTs the presence of tubes with lengths of 1263.33 ± 58.59 nm and diameters of 92.7 ± 21 nm. DRS spectra and Tauc plots allowed to estimate the bandgap values of TiO₂NTs films between 3.00 and 3.20 eV. The electrochemical characteristics of the ITO/TiO₂NTs films, decorated or not with AgNPs and dye, were evaluated by transient photocurrent (TP) and electrochemical impedance spectroscopy (EIS) on different compositions. The TP analysis showed that the photoanode did not respond without a light source, but when UV light was applied it showed significant photocurrent responses. The best result was obtained with the ITO/TiO₂NTs-dye composition, due to the reduction in bandgap value and the higher visible radiation absorption. EIS analysis showed a significant reduction in the charge transfer resistance in the TiO₂NTs films when exposed to UV radiation, and the dye deposition onto ITO/TiO₂NTs surface caused significant changes in the electrode’s properties. Finally, the films presented in this study can potentially contribute to the capture of solar radiation and conversion into electricity in DSSCs, being a sustainable and highly attractive alternative for energy production.

Nanostructure engineering and carbon incorporation can effectively achieve superior lithium storage performance of SiO₂ anode. However, the working operation at high rates and extreme temperatures remains a challenge for SiO₂-based anode. Here, SiO₂@N-doped carbon (SiO₂@NC) nanospheres encapsulated in the TiN/C nanofibers (SiO₂@NC@TiN/C) were fabricated via coaxial electrospinning. The SiO₂@NC@TiN/C with a robust structure and conductive shells exhibited excellent cycling stability and fast Li⁺ diffusion kinetics. The SiO₂@NC@TiN/C electrode delivered a superior rate performance (317.9 mAh g⁻¹) and ultra-long cycle life (284.5 mAh g⁻¹ after 3200 cycles) at 10 A g⁻¹. Furthermore, the SiO₂@NC@TiN/C electrode maintained an excellent cycling stability at 65 ℃ (420.6 mAh g⁻¹ after 300 cycles at 1 A g⁻¹). This research offered an ingenious design way to create a multilayer coated anode, which could exhibit good electrochemical performance under harsh conditions.

The non-aqueous sol–gel method is widely used to prepare metal oxides due to its superior ability to modulate nanostructures. However, Li_1.2Mn_0.54Ni_0.13Co_0.13O₂, a lithium-rich manganese-based material synthesized by this method, exhibits a high specific surface area. This high surface area can increase side reactions and cause a rapid decline in capacity. Sulfur doping on the surface of the material is achieved through secondary modification with thiourea treatment, resulting in enhanced electrochemical properties and stability. Elemental and morphological characterization, along with electrochemical testing, shows that sulfur surface doping effectively mitigates the rapid capacity decay associated with a high specific surface area. The high specific surface area, combined with the lattice broadening effect of sulfur doping, is significantly improving the kinetic polarization of the cell and enhancing both its performance and cycle stability. At 0.1C, the specific capacity of the cell increases from 244.4 mAh/g to 274.2 mAh/g in the first cycle. Additionally, the capacity retention rate improves from 48 to 70% after 300 cycles at 1C.

The ionic conduction properties of Li/Na metal halides have been extensively studied, with recent attention turning towards Al-based systems. However, limited studies have focused on alkali Al bromides. In this study, we explored the Na⁺ conduction properties of NaAlBr₄. Conductivity measurements at 30 °C revealed a Na⁺ conductivity of 1.2 × 10⁻⁵ S/cm, surpassing that of isostructural NaAlCl₄ threefold. Molecular dynamics (MD) simulations to elucidate the conduction mechanisms revealed that Na⁺ conduction was not observed in stoichiometric NaAlBr₄, which has high formation energies of Na⁺ vacancies and interstitials (0.88 eV and 0.73 eV, respectively). Nevertheless, a conductivity of 1.2 × 10⁻⁵ S/cm was observed. The activation energy for ion conduction was experimentally determined as 0.43 eV, and the migration energies were calculated as 0.26 eV (Na⁺ vacancies) and 0.16 eV (Na⁺ interstitials) by MD simulations. These discrepancies in ion conduction were partially explained by the role of transient defects enriched via ball milling in facilitating Na⁺ conduction on the particle surface, offering insights into the complex ion conduction of ball-milled NaAlBr₄.