ChemElectroChem最新文献

The present contribution describes an electrochemical system for the detection of alkaline phosphatase (ALP) enzyme inhibitors in seawater medium. Fluorescence spectroscopy and thermal unfolding results suggest that the state of free ALP is affected in this medium, yet the protein remains active. The enzyme activity can be evaluated using hydroquinone diphosphate as the substrate, with hydroquinone as the electrochemically monitored product. It has been demonstrated that encapsulation in conventional and organic modified silica matrices maintains ALP integrity, although diffusion across the formed monoliths hinders the electrochemical response. ALP@Phenyl-modified silica exhibits the best performance due to higher affinity between substrate molecules and aromatic moieties and, probably, to larger pore size. This electrochemical system can detect and quantify calyculin A in seawater at sub-nanomolar concentrations and it can also be employed for the development of electrochemical biosensors tailored for the marine environment.

Herein we report the fabrication of a simple electrochemical sensor based on an electrode containing reduced graphene oxide and molybdenum disulphide (RGO/MoS₂) as a conducting film onto the glassy carbon electrode (GCE) via a drop dry method to form GCE-RGO/MoS₂. The surface (GCE-RGO/MoS₂) was further modified with nickel hydroxide thin film using electrodeposition method to form GCE-RGO/MoS₂/Ni(OH)₂. The materials and modification steps were thoroughly characterized using microscopy and spectroscopy methods. The composite electrode, GCE-RGO/MoS₂/Ni(OH)₂, showed excellent electrocatalytic potential separation for the detection of dopamine, uric acid, and ascorbic acid. The electrocatalytic oxidation peak potentials were at 3 mV, 157 mV and 303 mV for AA, DA and UA, respectively. The composite electrode was also selective towards the determination of ascorbic acid (AA), dopamine (DA), uric acid (UA), and simultaneously in mixture of analytes. The low detection limits for AA, DA and UA were 1.17 μM, 0.15 μM and 1.15 μM, respectively. The composite electrode was applied for the detection of AA, DA and UA in spiked newborn calf serum samples with high percentage recoveries ranging from 96.6–100.8 % for AA, 92.8–104.2 % for DA and 99.4–102.3 % for UA.

Although anion-exchange membranes (AEMs) are commonly used in fuel cells and water electrolyzers, their widespread commercialization is hindered by problems such as low anion conductivity and durability. Moreover, the development of high-performance AEMs remains complex and time consuming. Here, we address these challenges by proposing an innovative approach for the efficient design and screening of AEM polymers using unsupervised machine learning. Our model, which combines principal component analysis with uniform manifold approximation and projection, generates an intuitive map that clusters AEM polymers based on structural similarities without any predefined knowledge regarding anion conductivity or other experimentally derived variables. As a powerful navigation tool, this map provides insights into promising main-chain structures, such as poly(arylene alkylene)s with consistently high conductivity and polyolefins with exceptional performance depending on the substituent. Furthermore, assisted by key molecular descriptors, inverse analysis with this model allows targeted design and property prediction before synthesis, which will significantly accelerate the discovery of novel AEM polymers. This work represents a paradigm shift not only in AEM research but also generally in materials research, moving from black-box predictions toward interpretable guidelines that foster collaboration between researchers and machine learning for efficient and informed material development.

Electrocatalytic nitrate reduction is a promising approach to remove harmful nitrate and produce ammonia in aqueous media. Here, we demonstrate how 3D printed polymer electrodes can be electroless plated with a bimetallic NiCu alloy film suitable for sustained nitrate-to-ammonia reduction. Characterization by powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning/transmission electron microscopy and energy-dispersive X-ray spectroscopy indicate that the electrode has a two-layer structure consisting of polymer/ coating layer of metal alloys. The composite electrode shows high-performance in the nitrate-to-ammonia electroreduction, giving NH₃ Faradaic efficiencies of up to 83 % and NH₃ yield rates up to 860 μg/(h cm²) at −0.38 V vs. RHE. We show that the electrode can easily be integrated into a Zn-nitrate battery, giving a power density of 3.8 mW cm⁻² with continuous NH₃ production. The system combines three productive outputs, that is removal of nitrate pollutants, synthesis of valuable ammonia and generation of “green” electricity.

The front cover image depicts the sulfide-based solid electrolyte and silicon anode interface in all-solid-state lithium-ion batteries. It also emphasizes that the investigation of the electrode/electrolyte interface is essential for designing high-energy batteries, and more in-depth analysis characterization tools have to be developed and utilized to fully understand the interface kinetics and charge transport mechanism for designing highly efficient battery systems for next-generation electric vehicles and portable devices. More information can be found in the Perspective by Jaekyung Sung and co-workers (DOI: 10.1002/celc.202400219)

The cover feature illustrates an anion exchange membrane (AEM) material map, visually summarizing the relationship between chemical structure and anion conductivity of currently reported AEMs. This map allows researchers to identify promising regions for high-performing AEM, and then design next generation polymer structure by pinpointing structural features associated with superior conductivity. Consequently, through this map, researchers can gain insights into tailoring new AEM structures for optimized performance by studying the positions of well-performing AEMs. More information can be found in the Research Article by Tsuyohiko Fujigaya, Koichiro Kato, and co-workers (DOI: 10.1002/celc.202400252).

Although capacitive deionization (CDI) technology has been studied intensively for more than 20 years, its commercialization remains in the initial stage, which is partly caused by the insufficient knowledge exchange between academia and industry. This concept reviews multiple scaling-up efforts in the CDI technology for treating real water streams, following a case-by-case fashion. While the cell architecture in pilot scales is limited to the membrane CDI, highlighting the necessary role of ion-exchange components during scaling-ups, different ways of electrode stacking, i. e., monopolar and bipolar, are available. The performance indicators of these CDI systems when treating real water streams are summarized to gain insights into industrial practices. Importantly, key discrepancies in cell components and performances between pilot-scale and lab-scale studies are emphasized. The main challenges in large-scale CDI systems for industrial purposes are discussed, providing hints for a better integration of research and applications.

Rechargeable polymer-based solid-state batteries with metallic lithium anodes and LiNi_xMn_yCo_1−x−yO₂ (NMC)-based cathodes promise safer high-energy-density storage solutions than existing lithium-ion batteries, but have shown challenging to realize. The failure mechanisms that have been suggested for these battery cells have mostly been related to the use of a metallic lithium anode and formation of dendrites during cycling. Here, we approach the issue of using solid polymer electrolytes (SPEs) vs. NMC cathodes by employing a range of materials based on poly(ϵ-caprolactone-co-trimethylene carbonate) (PCL-PTMC) with different salts under various cycling conditions. It is seen that although the ionic conductivity of the electrolyte can be improved by exchanging the lithium salt, it does not immediately correlate to better cycling performance. However, increasing the temperature during battery cycling to improve the ion transport kinetics lowers the polarization of the battery cell and full capacity can be achieved at an upper voltage cut-off that is appropriate for the polymer electrolyte. For these electrolytes, the limit is demonstrated to be 4.4 V vs. Li⁺/Li, and cycling with NMC-111 cathodes is thereby possible provided that the upper cut-off is limited to below this limit.

This research investigates the impact of laser-structuring of lead electrodes on the selectivity and production rate of hydrofuroin, a valuable jet fuel precursor derived from furfural (FF). Laser structuring of electrodes led to a slight enhancement in hydrofuroin selectivity, along with an improved production rate, suggesting promising advancements in electrosynthesis methodologies. The addition of acetic acid as an impurity did not significantly affect the selectivity or the production rate. This finding indicates that the catalytic activity of the electrode surface was not diminished by this impurity. Analysis via high-performance liquid chromatography revealed the presence of two isomers of hydrofuroin, indicating a complex reaction pathway. Combined experimental and molecular dynamics simulations indicated inner sphere adsorption of FF and H⁺ ions and outer sphere dimerization reaction to form hydrofuroin. These findings offer insights into surface morphology, adsorption, and reaction pathways, guiding future optimization of catalytic systems for sustainable chemical synthesis.

The monitoring of antioxidants is crucial to prevent damage caused by reactive oxygen species (ROS). In this study, we introduce an innovative electrochemical sensor tailored for detecting riboflavin (RF), a powerful antioxidant. The sensor was developed by modifying a gold electrode (AuE) with cobalt oxide (Co₃O₄) and reduced graphene oxide (rGO). The resulting nanocomposite-modified electrode (AuE/Co₃O₄-rGO) exhibited a substantial surface area of 0.41 cm² in the redox probe, leading to an enhanced RF peak characterized by remarkably low charge transfer resistance (1.61 KΩ) and a high exchange current density (18.6 μA/cm²). Under optimized conditions, the sensor achieved a limit of detection (LOD) for RF at 1.30 μM, over a concentration range of 6.5–42.2 μM. These results highlight the sensor's potential applicability in real-world scenarios, including the analysis of milk and pharmaceutical samples. A kinetics study revealed that the electrochemical reaction involving RF is adsorption-controlled, emphasising the critical role of surface interactions. The modified electrode's interaction with RF significantly influences overall reaction kinetics. These findings were further supported by density functional theory (DFT) calculations and molecular simulations. Our nanocomposite-modified electrode provides valuable insights into the atomistic interactions governing sensor performance, advancing the field of electrochemical sensing for antioxidants like riboflavin.