International Journal of Electrochemical Science最新文献

A simple and efficient ultrasonic-assisted strategy was used to prepare the nanocomposite of Vulcan XC-72R carbon (VXC-72R) nanoparticles and Zr(IV)-based metal-organic framework (UIO-66) nanoparticles. For the multifunctional VXC-72R@UIO-66 nanocomposite, VXC-72R nanoparticles possessed good conductivity property and good dispersion, which were conductive to form the interconnected carbon conductive channels; UIO-66 nanoparticles could improve the accumulation ability of methyl parathion (MP) because of the high affinity of Zr-O groups with phosphoric groups. Moreover, the introduction of VXC-72R nanoparticles could effectively make up the conductivity property of UIO-66 nanoparticles. The VXC-72R@UIO-66/GCE sensor presented good MP detection performance with limit of detection (LOD) of 1.35 nM (Linear MP concentration range: 0.01–10 μM). When used for the detection of MP in juice samples, the VXC-72R@UIO-66/GCE sensor showed acceptable recoveries of 96.00–104.67 %.

Steel with enhanced corrosion resistance in both simulated deep sea and shallow sea environments was developed by adding cerium (Ce) to high-strength low-alloy (HSLA) steel. Through conventional characterization techniques, the electrochemical performance, rust layer composition, and protective properties of the steel were analyzed. The study found that the steel exhibited superior corrosion resistance when the Ce content was 0.2 wt%. This improvement is largely attributed to Ce's role in promoting the formation of α-FeOOH, which results in a dense and protective rust layer. Additionally, Ce consumes oxygen and inhibit the cathodic depolarization reaction. Furthermore, due to the low oxygen solubility in the simulated deep sea environment, the cathode reaction is further inhibited, leading to a lower corrosion degree in the deep sea environment compared to the shallow sea environment.

This study reports the deposition of Ni-W-SiC nanocoatings on the 45-steel using the ultrasound-assisted electroless deposition (UELD) technique. The hardness and corrosion resistance of the nanocoatings were evaluated through microhardness tests and electrochemical analyses. The surface, cross-section, phase composition, and abrasion morphologies of the coatings were studied using scanning electron microscopy and X-ray diffraction. The findings indicated that the Ni-W-SiC coating obtained at 200 W showed a compact, fine, and flat microstructure with a porosity of only 0.03 %. As the ultrasonic power during the UELD process increased from 0 W to 200 W, the SiC content in the coating rose from 2.77 to 4.16 wt% The maximum bonding force of the coating synthesized without ultrasound was approximately 89.8 N. However, the bonding force of the coatings significantly decreased with increasing ultrasonic power. The coating’s thickness also increased, from 11.09 μm at 0 W to 14.97 μm at 300 W. At 200 W ultrasonic power, the diffraction peaks of the coating were both the lowest and broadest among all the coatings. Further, the coating achieved the highest microhardness value of 676 HV. At 200 W ultrasonic power, the coating's corrosion current density was 1.63×10⁻⁷ A/cm², which is only one-twelfth that of 45 steel, demonstrating exceptional corrosion resistance. The electrochemical impedance spectroscopy (EIS) testings indicated that an excellent corrosion resistance of Ni-W-SiC coating was deposited by using a 200 W ultrasonic power. This study provides a technical support for the preparation of nickel-based composite coatings.

A Fe-Co dual-metal co-doped nitrogen-containing carbon composite (FeCo-HNC) was prepared by adjusting the ratio of iron to cobalt as well as the pyrolysis temperature with the assistance of functionalized silica template. Fe₁Co-HNC, which was made from 1D carbon nanotubes and 2D carbon nanosheets with a rich mesoporous structure, presented exceptional oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic activity. The ORR half-wave potential is 0.86 V (vs. reversible hydrogen electrode, RHE), and the OER overpotential is 0.76 V at 10 mA cm⁻² with the Fe₁Co-HNC catalyst, which can be applied to zinc-air batteries with superior performance. It is worth noting that the zinc-air batteries with Fe₁Co-HNC-1000 as the cathodic catalyst achieved the highest power density of 94.9 mW cm⁻² under a current density of 159.8 mA cm⁻². This method provides a promising strategy for fabricating efficient transition metal-based carbon catalysts.

This research examines the influence of yttrium oxide (Y₂O₃) nanoparticles as reinforcing particles on the microstructure and corrosion resistance of Ni-Y₂O₃-MgO composite coatings deposited by pulse electrodeposition. Varying Y₂O₃ contents are prepared on the Q235 steel substrate using the composite electrodeposition technology. The efficacy of the coatings was evaluated using a range of analytical methods, including SEM, EDS, XRD, wear investigation, and electrochemical testing. The results demonstrate that the incorporation of Y₂O₃ nanoparticles has a substantial effect on refining the grains of the composite coating, thereby improving its surface flatness and density. Particularly, the coating demonstrated the highest surface quality and the smallest particle size at 10 g/L Y₂O₃ content which may be associated with the fact that the high surface activity and large specific area of the Y₂O₃ nanoparticles promote the nucleation rate and inhibit the crystal growth during the deposition process of the composite coating. The presence of Y₂O₃ in the coating increased the self-corrosion potential and decreased the self-corrosion current density, thereby improving its corrosion resistance. Particularly, the composite coating containing Y₂O₃ at a concentration of 10 g/L exhibits the most effective resistance against corrosion. Furthermore, the inclusion of Y₂O₃ (10 g/L) effectively decreases the wear volume of the coating while simultaneously enhancing its hardness and wear resistance. This study provides a new way for the preparation and characterization of metal-based nanocomposite coatings.

In this paper, laser-induced graphene (LIG) with high porosity and large specific surface area was prepared by laser induction technology. Then a selective electrochemical sensor based on LIG was proposed for determination of bisphenol A (BPA). Under optimal conditions, the developed sensor emerged an efficient electrocatalytic activity towards the redox of BPA. The results show that it presents a wide detection range of 100 nM ∼ 1.0 mM and a low detection limit of 50.68 nM with good anti-interference and stability. Furthermore, the sensor can be applied to detect BPA in real plastic samples with the recovery rate of 98.6∼105.8 %, which indicated that the sensor has potential for future applications in trace detection of BPA.

The corrosion process of steel alloys in acidic environments is typically considered to be governed by charge transfer (activation) control. Nonetheless, in aerated solutions, mass transfer can affect the electrochemical measurements. This study examines the corrosion inhibition of N80 steel in 1 M sulfuric acid using okra leaf extract (OLE), utilizing electrochemical polarization techniques at various concentrations of the inhibitor and different temperatures. The outcomes of electrochemical data of current densities and overpotentials were fitted to a high-order polynomial equation and the Maclaurin series formula. The coefficients of the high-order polynomial equation were evaluated using a non-linear regression method, which is in turn used in the Maclaurin series formula. A series of complex equations were derived, incorporating a factor (β) to account for the impact of mass transfer on the activation-controlled corrosion process. A complex equation set of β-models was processed using MATLAB computer programming. In addition, a β-model was correlated to a mass transfer correction factor (γ) and polarization resistance (R_p). β-values ranged from 0.005 to 0.916 (average 0.198), which indicates the presence of a mass transfer effect in addition to the activation effect (mixed control corrosion mechanism). Conversely, the polarization resistance (Rp) increased with higher inhibitor concentrations and decreased as the temperature rose.

In this study, we explored an innovative approach to enhance the corrosion resistance of AZ31B magnesium alloy in 3.5 wt% NaCl solution by applying an Al-Si coating using cold metal transfer (CMT)-based wire arc additive manufacturing (WAAM) technology. The findings indicate that the Al-Si coating improved the alloy’s corrosion performance, with a more noble self-corrosion potential (- 0.97 V_SCE) and lower self-corrosion current density (3.68 μA/cm²) compared to untreated AZ31B. Long-term immersion tests demonstrated that AZ31B suffered from severe localized corrosion, while Al-Si coating maintained a uniform corrosion profile. Analysis of the corrosion products showed that the Al-Si coating primarily comprised oxidized Mg and hydroxide Al, with minimal oxidized Al and Si, in contrast to the mainly metallic and hydroxide Mg on AZ31B. By reducing the electrochemical activity and enhancing the stability of corrosion products, the Al-Si coating significantly improved the corrosion resistance of AZ31B substrate. This study suggests a promising avenue for advancing the durability of magnesium alloys in corrosive environments.

Sulfamic acid (SA) has a low acid-rock reaction rate and can be used for deep high-temperature acidizing. However, the inhibition effect of existing corrosion inhibitors at deep high temperatures is greatly reduced. Through experiments, it is found that corrosion inhibitors such as imidazoline (OAI), cinnamaldehyde (CA), C14 quaternary ammonium salt (C14-GN), and potassium iodide (KI) have good corrosion inhibition effect, the average corrosion inhibition rate can reach 99 %, and the corrosion rate is less than 2 g/m² h. The experimental results show that the film formation of a single inhibitor is uneven and the pitting corrosion is serious. In contrast, the mixed-use of many kinds of inhibitors can effectively inhibit the pitting corrosion, and the corrosion rate is less than 1.6 g/m² h. And it can effectively inhibit pitting corrosion. At 363 K, the corrosion inhibition rate is 99.9 % and the corrosion rate is 1.1 g/m²·h. Through the orthogonal test, it is concluded that the best inhibitor ratio is OAI: CA: C14-GN: KI = 3:3:3:2. The optimized inhibitor has the best synergistic effect, can play an important role at high temperature, make the film uniform and dense, and improve the corrosion inhibition effect of the solution of sulfamic acid with the investigated inhibitor.

To improve the comprehensive protection performances of steel C1045 surface, the Ni–Co–P alloy coatings with varying CoSO₄·7 H₂O concentration (0, 10, 20, 30, 40, 50, 60 and 70 g·L^–1) were successfully prepared by an electrodeposition technique on a steel C1045 surface. The effect of the addition of CoSO₄·7 H₂O in the plating solution on the surface microstructure, elemental composition, crystallite size, microhardness, wear and corrosion resistance of the Ni–Co–P alloy coatings were analyzed by using a scanning electron microscope, an energy dispersive spectroscopy, an X-ray diffraction, a microhardness tester, a friction wear tester and an electrochemical workstation, respectively. The results indicated that the Ni–Co–P alloy coating exhibited a flatter morphology, compact microstructure and more excellent properties compared with Ni–P alloy coating, and the addition and variation of CoSO₄·7 H₂O in the plating solution had significant effects on the surface microstructure and comprehensive protection performances Ni–Co–P alloy coating. Notably, when the mass concentration of CoSO₄·7 H₂O in the plating solution was 50 g·L^–1, the Ni–Co–P alloy coating had the highest content of Co element (22.67 wt·%), smallest crystallite size (20.41 nm) and highest microhardness (716.2 HV_0.1). Furthermore, its wear resistance and corrosion resistance were considerably improved compared to that of the Ni–P alloy coating. The minimum average dynamic friction coefficient, wear scar width and depth of Ni–Co–P alloy coating at 50 g·L^–1 were 0.47±0.02, 450.9 µm and 14.1 µm, respectively. The corrosion current density (I_corr) of Ni–Co–P alloy coating was the smallest (0.68 µA·cm^–2), the corrosion rate (R_corr) was slowest (8.25 µm·year^–1), and the polarization resistance (R_p) of the Ni–Co–P alloy coating was highest (29.83 kΩ·cm²). The corrosion resistance of Ni–Co–P alloy coating was best.