International Journal of Electrochemical Science最新文献

Graphene, a two-dimensional nanomaterial with exceptional properties, has emerged as a promising candidate for the development of flexible substrate sensors for human motion monitoring. This review comprehensively explores the recent advances in graphene-based sensors, focusing on their fabrication techniques, sensing mechanisms, and applications in detecting various physical and physiological parameters. The unique electrical, mechanical, and chemical properties of graphene, such as high carrier mobility, excellent mechanical strength, and large surface area, are discussed in detail. The review delves into the different synthesis methods of graphene and graphene oxide, as well as the techniques for integrating them onto flexible substrates. Graphene-based strain and pressure sensors, which exploit the piezoresistive and piezoelectric properties of graphene, are extensively examined, along with strategies for enhancing their sensitivity and performance. The application of these sensors in monitoring joint movements, respiration, and cardiovascular parameters is highlighted. Additionally, the review explores the potential of graphene-based electrochemical sensors for detecting electrophysiological signals and biochemical analytes, such as glucose and lactate. Finally, the challenges and future directions in the field of graphene-based flexible substrate sensors are discussed, emphasizing the need for further research to address issues related to scalability, reproducibility, and integration with wireless electronics.

Ru-based nanomaterials have a lot of potential as electrochemical hydrogen evolution reaction (HER) catalysts; however, achieving a uniform dispersion of Ru nanoparticles on substrate materials remains a key challenge. To achieve this, in the current study, we formed NF/Co(OH)₂/Ru by electrodepositing Ru nanoparticles onto Co(OH)₂ nanoneedles. The Co and O vacancies in the sample promoted water decomposition and the cleavage of O-H bonds, while the high surface energies at the apexes of the Co(OH)₂ nanoneedles supported the even growth and attachment of Ru nanoparticles. In addition, the electron-rich Ru nanoparticles aided in the desorption of hydrogen intermediates. Compared to recently published Ru-based HER materials, the NF/Co(OH)₂/Ru material created in this study shown improved electrochemical characteristics, with an overpotential of 20 mV at 10 mA·cm⁻² and a Tafel slope of 35.43 mV·dec⁻¹. Therefore, this material and the findings of this study are expected to contribute to HER research.

High-strength low-alloy 921 A steel faces significant corrosion challenges in harsh marine atmospheric conditions, threatening marine and energy industry safety. This study investigates the corrosion behavior of 921 A steel through accelerated tests in a specially developed multi-factor coupled corrosion chamber. Combining the multi-factor coupling cyclic corrosion test method with finite element numerical simulation, the long-term corrosion behavior can be accurately predicted, and the power function relationship between the corrosion rate and time of the test steel is obtained, which is expressed as C=0.2259 t^–0.5182. Analysis identified α-FeOOH, Fe₃O₄, γ-FeOOH, Cl^—, and Cr in corrosion layers. First-principles calculations and XPS analysis showed Cr oxidation inhibits Cl^— adsorption and diffusion, highlighting the steel’s corrosion resistance. Finite element analysis and outdoor corrosion data confirmed the corrosion rate and time correlation, proving simulation reliability. This research provides crucial insights into 921 A steel’s corrosion resistance in marine environments, benefiting marine engineering.

The development of fuel cells is urgently needed, leading to increasing demand for electrodes with low catalyst loading, high utilization, and straightforward fabrication. In this work, we successfully designed and synthesized Pt nanosheet electrocatalysts grown in situ on treated carbon cloth (Pt/CC) using a simple and rapid electrodeposition technique. At a pulse peak current density of 300 mA cm⁻², the catalyst exhibited impressive Pt surface coverage uniformity, ultralow Pt loading, and an ultrathin nanosheet structure, providing a large number of active sites for electrochemical reactions. With a Pt loading of only 0.02 mg cm⁻², Pt/CC-300 provides an 11-fold improvement in hydrogen oxidation reaction (HOR) performance over commercial Pt/C catalysts. The electrode can be directly employed as an anode electrode without any additives or secondary treatment. This not only simplifies the production process but also paves the way for more economical and efficient fuel cell technology.

A sensitive and selective sensor based on a polythiourea-modified glassy carbon electrode (polythiourea/GCE) was fabricated for electrochemical determination of fenitrothion (FT). Cyclic voltammetry and impedance spectroscopy were used to characterize the electrochemical behavior of polythiourea/GCE. The chemical and structural characteristics of the modified electrode were studied with UV-V is and FTIR spectroscopy techniques. The polythiourea (GCE) demonstrated faster electron transfer kinetics, a small charge transfer resistance, and an enhanced electroactive surface area of 0.173 cm², which was two times greater than that of the bare GCE. The electrochemical behavior of FT at polythiourea/GCE was studied using cyclic voltammetry and square wave voltammetry. The reduction of FT on the surface of the modified electrode followed an adsorption-controlled process, and interestingly, the electrode surface coverage determined from chronocoulometric measurements showed 3.3 times higher accumulation of FT than at the bare GCE. Under optimized experimental parameters, the adsorptive stripping square-wave voltammetric current signal of FT at polythiourea/GCE exhibited an excellent sensitivity of 10.05 μA μM⁻¹, good linearity ranging from 0.05 to 10 µM and 10–50 µM, and low limits of detection and quantification of 2.1 and 7.0 nM, respectively. The selectivity of the sensor was also evaluated in the presence of several common interfering substances, such as nitrophenol, malathion, diazinon, ascorbic acid, K⁺, Mg^2+, and Zn²⁺ ions, and the percent error was less than ±5 %. The practical application of the suggested electrochemical sensor for FT determination was carried out in tomato, sweet potato, and cabbage samples. The average recoveries of the spiked samples were between 94.3 % and 110 %, indicating that the developed method is accurate for FT determination.

A new self-supporting material contained nanorods α-FeOOH and three-dimensional skeleton graphene foam (3D Graphene Foam, 3DGF) was prepared by hydrothermal method. The growth mechanism and phase change rules of nanorods α-FeOOH@3DGF were studied to obtain the electrochemical lithium storage performance. The results showed that growth mechanism of nanorods α-FeOOH was accompanied by the consumption of nanoparticles β-FeOOH. If the hydrothermal time reached to 12 h, the nanoparticle β-FeOOH phase completely disappeared with only rod-shaped α-FeOOH@3DGF single phase obtained. Rod-shaped α-FeOOH@3DGF was used as anode material of lithium-ion batteries and the reversible specific capacity remained at about 305 mAh·g⁻¹ after charging and discharging 250 times at 500 mA·g⁻¹, with significantly cycling stability compared with that of the monomaterial α-FeOOH.

It is vital to optimize the processing parameters and reveal the leveling mechanism of various micro-discharges for titanium alloy. In this paper, TC4 titanium alloy was polished within aqueous fluoride-type solution. The polished surface roughness can be reduced from the original Ra 1.13 μm to 0.213 μm with the voltage range of 250–300 V. The process of plasma electrolytic polishing can be divided into three different stages: conventional low voltage electrolysis, vapor gaseous envelope luminescence, and spark micro-discharge. Correspondingly, it appears different colors for the oxidized titanium alloy surface formed with different processing parameters. The mechanism of plasma electrolytic polishing is related with the formation, growth, and loosening of anodic oxides formed on titanium alloy, as well as the final ultrasonic removal of the loosened oxide debris.

As a new type of efficient electrochemical energy storage system, the supercapacitor serves as an effective means to support the development of clean energy, with the electrode material being the key determinant of performance. The electrode material Pt-NiCo₂O₄/C was prepared in this paper by stepwise hydrothermal and calcination methods using ZIF-67 as a template, aiming to improve specific capacitance performance and stability. Pt-NiCo₂O₄/C achieved a specific capacitance of 1665.3 F/g at a current density of 1.0 A/g, and maintained 94.49 % of the original specific capacity after 3500 cycles at a current density of 4.0 A/g. The excellent specific capacitance performance of the Pt-NiCo₂O₄/C electrode material makes it a promising potential candidate for energy storage applications.

In this paper, cytotoxicity-free Ti-10Ta-2 Nb-2Zr titanium alloy was prepared by selective laser melting additive manufacturing. The effect of solution and annealing heat treatment on the structure and microhardness were investigated. Electrochemical performance in Ringer’s solution at 37℃ was evaluated. This electrochemical evaluation was performed through the open circuit potential variation as the immersed time, potentiodynamic polarization curves, and electrochemical impedance spectroscopy tests. The results show that main phase composition of as-built and heat-treated specimens was the α/α′ phase. The specimen annealed at 500℃ presented a small amount of β phase. The solutionized and annealed specimens had basket-weave microstructure with distributed micro-scaled α/α′ lamellas. The microhardness of as-built specimens was 400.48 ±12.31 HV. After solution and water quenching, the microhardness dramatically increased to 533.85 ±24.67 HV. The microhardness slightly decreased to 495.46 ±4.85 and 488.8 ±13.84 HV after annealing at 300 ℃ and 500 ℃, respectively. Compared with the as-built specimen, the solutionized and annealed specimens had much lower corrosion current density and higher corrosion resistance.

This review focuses on the advancements in electrochemical sensing of epinephrine using carbon nanomaterials. Epinephrine, a vital catecholamine, plays a significant role in numerous physiological processes, including the "fight or flight" response, blood pressure regulation, and glucose metabolism. Accurate detection of epinephrine levels is crucial for diagnosing and managing various medical conditions such as anaphylaxis, cardiac arrest, and severe asthma. Carbon nanomaterials have emerged as promising candidates due to their high surface area, excellent conductivity, and biocompatibility, which enhance the sensitivity and selectivity of electrochemical sensors. The review discusses various types of carbon nanomaterials, including graphene, carbon nanotubes, and carbon nanofibers, highlighting their unique properties and applications in epinephrine sensing. It also covers the fabrication techniques of these sensors, their performance metrics, and the challenges faced in their development. This comprehensive overview aims to provide insights into the current state and future prospects of carbon nanomaterial-based electrochemical sensors for epinephrine detection, emphasizing the need for further research to overcome existing limitations and improve clinical applicability.