In the field of biosensors, polymer thin films such as Nafion, poly(vinyl alcohol) (PVA), chitosan, and cellulose acetate (CA) have been introduced onto electrode surfaces to enhance the stability of catalytic materials and/or impart electrode selectivity. In this study, we investigated indium tin oxide (ITO) electrodes-whose modification with polymer protective layers has been relatively less explored-and evaluated the effects of polymer-layer incorporation in terms of (1) improved stability of the catalytic material and (2) the feasibility of charge-selective electrochemical detection. In addition, by comparing planar ITO with nanoporous-structured ITO electrodes, we aimed to identify the support that more clearly exhibits the protective effect and stability provided by the polymer layer. These findings provide a basis for expanding design and fabrication strategies for ITO-based biosensors.
In this study, CdSe quantum dots (QDs) were grown on mesoporous TiO2 films using the successive ionic layer adsorption and reaction (SILAR) method, and the effect of cationic bath pH on QD growth behavior and photoelectrode performance was systematically investigated. By introducing triethanolamine (TEA) into the Cd2+ precursor solution, the pH was increased above the point of zero charge of TiO2 , inducing a negatively charged surface that enhances electrostatic attraction toward Cd (2+) ions. As a result, the growth rate and surface coverage of CdSe QDs were significantly increased compared to the case without TEA. The accelerated growth and higher QD density were confirmed by visible color evolution, UV-Vis absorption spectroscopy, and transmission electron microscopy. Photoelectrochemical characterization revealed that the increased CdSe loading leads to substantially enhanced photocurrent generation in both quantum dot-sensitized solar cells and photoelectrochemical cells. Notably, the CdSe-sensitized TiO2 electrode prepared under basic conditions exhibited approximately 2.3 times higher photocurrent density during photoelectrochemical oxidation, along with stable and reproducible hydrogen evolution. These results demonstrate that electrostatic control of cation adsorption via pH modulation is a key parameter governing SILAR-grown metal chalcogenide QDs, providing valuable design guidelines for high-performance quantum dot-sensitized photoelectrodes.
Control of the microstructure of photocathodes is a key factor governing the efficiency of organic pollutant degradation in photoelectrochemical (PEC) water purification systems. Cu2O photocathodes were prepared via electrodeposition, and the relationship between applied deposition voltage, crystal structure, and PEC water purification performance was investigated. To promote preferential growth along the (111) crystallographic direction, the electrolyte pH was maintained at 11, and the potential window for stable Cu2O deposition was determined to be 0.3 to 0.7 V by linear sweep voltammetry. The structural properties of the electrodeposited Cu2O films were characterized by X-ray diffraction and scanning electron microscopy, while their PEC performance was evaluated using methyl orange as a model organic pollutant. The Cu2O photocathode deposited at 0.5 V exhibited a pronounced (111) preferred orientation, enlarged grain size, and a uniform film morphology, resulting in the highest photocurrent density and excellent operational stability under simulated 1-sun illumination. These findings demonstrate that precise control of electrodeposition voltage is crucial for optimizing the PEC performance of Cu O photocathodes and highlight their potential for environmentally friendly water purification applications.
Lithium-ion batteries (LIBs) are the dominant energy storage technology for portable electronics, electric vehicles, and grid applications. However, their performance deteriorates significantly at sub-zero temperatures due to sluggish electrochemical kinetics, reduced ion conductivity, and unstable electrode-electrolyte interfaces. This review summarizes the recent progress in low-temperature LIBs, focusing on electrode material design, electrolyte engineering, interface modification, and emerging strategies such as solid-state electrolytes and external thermal management. Challenges and future directions for realizing practical low-temperature LIBs in extreme environments are also discussed.
Anion exchange membranes (AEMs) underpin fuel cells and water electrolyzers, requiring a balance of ionic conductivity, chemical stability, dimensional control, and mechanical robustness. Recent machine learning (ML) studies introduce condition-aware surrogate models that predict anion conductivity and, in some cases, alkaline stability across diverse AEM chemistries. Interpretable pipelines relate structure and test conditions to performance, while unsupervised mapping supports pre-synthesis exploration. Scalable inverse-design workflows combine ML with heuristic search to screen large virtual libraries under conductivity-stability criteria. At the device level, data-driven models highlight membrane and operating parameters that govern anion exchange membrane water electrolysis (AEMWE) performance. This mini review summarizes recent progress and outlines a concise workflow, i.e., condition-aware meta-data, multi-scale featurization, interpretable supervision, unsupervised mapping, and ML-guided screening, for reproducible materials-to-device translation.
Ag@Ir core-shell nanostructured catalysts were synthesized through a chemical reduction method to investigate the role of noble-noble interfacial coupling in the oxygen evolution reaction (OER) under acidic conditions. Composition optimization by XRF identified Ag@Ir(1:1) as the most active configuration, achieving a mass activity of 6.39 A mg(-1) and an overpotential of 250 mV at 10 mA cm(-2) (85% iR compensation). XPS revealed weak interfacial electronic coupling between Ag and Ir, resulting in moderate charge redistribution from Ir to Ag and an electron-deficient Ir surface enriched in Ir3+/Ir4+ species while preserving the metallic nature of both components. This electronic interaction subtly modulates Ir oxidation states and facilitates OER kinetics without structural reconstruction. Electrochemical testing confirmed steady performance with only a similar to 30 mV increase in overpotential after 12 h of operation. The chemically inert Ag core maintains interfacial integrity and supports controlled electronic inter-action, leading to balanced activity and durability. These results establish Ag@Ir as a model noble-noble system for understanding interfacial electronic behavior in Ir-based OER catalysts.
Metal-organic frameworks (MOFs) have emerged as promising electrode materials for lithium-ion batteries (LIBs) owing to their exceptionally high specific surface areas, tunable porosity, and modular control over structure and electronic properties via reticular chemistry. These attributes enable the use of MOFs in both anodes and cathodes. In particular, MOFderived porous nanostructures preserve the parent pore network, buffer the volume change during cycling, and deliver high capacities, thereby improving long-term cyclability on the anode side. Cathode applications, however, are often limited by the intrinsically low electrical conductivity and structural fragility of many MOFs. To address this, recent strategies include forming composites with conductive carbons, heteroatom doping, synthesizing 2D conductive MOFs, applying MOF-derived carbon/metal coatings, and employing chelating MOF interlayers to stabilize interfaces and mitigate transition-metal crossover while facilitating Li-ion transport. This review organizes summarized recent developments of MOFs for enhanced ion transport and stability. Remaining challenges in large-area electrode fabrication, chemical/electrochemical durability, and cost/process compatibility are discussed, together with perspectives toward practical MOF-based LIB electrodes.
As the human pain controls depend on the brain neuro current, here assay is related to specific nerve potential detection, nerve pain induced amplification current detection, such as Depression, suicidal impulse, cancer pain, disease pain, dementia, epileptic pain signals, etc. For this purpose, the brain current was analyzed by electrochemical three-electrode systems using 0.1-mm micro wire in vivo probe, which probe was made by using carbon nano tube paste coated needle type. Here working electrode was inserted in the rat brain's muscle core with a 0.3-mm-diameter needle type Ag/AgCl Cl-coated Ag wire reference, and counter electrode of 0.1-mm-diameter Pt micro needle was inserted 5 mm deep into the in vivo muscle skin, under anesthesia with 2.0 similar to-2.0 V potential windows, 50 mv/s cyclic scan and 1.0x10(-5) A chrono amperometric sensitivity on the body systems. Under the optimum conditions, diagnostic application was performed to such as smell signal, muscular strength, five/sense assay and thinking neuro current. These neuro diagnostic technologies can include auditory sonar recognition, odor diagnosis, texture recognition, emotion recognition, visible color change recognition, etc. It can also amplify emotional recognition such as joy, hate, love, sadness, etc. And it can extend the pain of the skin or in-vivo whole body.
Spent lithium-ion batteries (LIBs) may be exposed to a wide range of temperatures during recycling, depending on environmental conditions and seasonal variations. Consequently, evaluating the disassembly safety and the quality of recovered cathode materials under extreme temperatures is crucial. In this study, NCM-type spent LIB cells were subjected to overdischarge at-20 C, 0 C, 25 C, and 50 C, and the changes in internal resistance at different depths of discharge (DOD) were analyzed. Following discharge to 0 V, voltage recovery time and cell temperature were recorded, and the dismantled cathode materials were characterized using SEM-EDS, ICP-OES, and XRD. Voltage rebound occurred under all conditions, with recovery time varying with temperature. Low-temperature discharge (-20 C) caused rapid voltage drops and internal resistance increases at early and late stages, while high-temperature discharge (50 C) exhibited prolonged voltage recovery, maintaining discharge completeness. Post-disassembly analysis revealed minor particle damage and reductions in Li, Ni, Co, and Mn contents, whereas the composition ratio and layered structure remained stable without impurity intrusion. These findings provide fundamental insights for optimizing recycling processes and designing safe dismantling procedures for spent LIBs.
In this work, we studied the electrochemical behavior of an osmium-based compound ([Os(4-4'-dimethoxy-2-2'-bipyridine) (2) (pyridine-NH2 )PF6 ]; Os-1) on an indium tin oxide (ITO) electrode and evaluated its role as an electron-transfer mediator in the oxidation of p-aminophenol (p-AP). Os-1 exhibited reversible and stable redox characteristics on the ITO electrode. In the presence of p-AP, compared to the mediator-free condition, the oxidation peak potential shifted to that of Os-1, accompanied by a significant increase in current. These results demonstrate that Os-1 functions as an effective electron-transfer mediator in the oxidation of p-AP, thereby enhancing the catalytic activity.
This review systematically explores the potential and structural advantages of metal-organic frameworks (MOFs) and MOF-derived electrocatalysts in the electrochemical CO2 reduction reaction (CO2RR). MOFs provide high surface area, tunable metal sites, and flexible structural motifs that enable the selective conversion of CO2 to valuable products such as CO, formate, and multicarbon compounds. Focusing on three recent representative studies, this work analyzes: (1) MOF-based structural strategies for active site design, (2) Ni nanoparticles embedded in nitrogen-doped carbon matrices derived from MOFs, and (3) Sb-doped Bi-based catalysts with enhanced formate selectivity. These studies demonstrate how metal doping, intermediate stabilization, and electronic structure modulation contribute to performance optimization and durability. By comparing these approaches, this review outlines the key principles in MOF-derived catalyst design and highlights promising future directions toward scalable, high-efficiency CO2RR electrocatalysts.
Xanthine is an intermediate in purine metabolism, synthesized through the oxidation of hypoxanthine and subsequently converted to uric acid. Elevated levels of xanthine in the body are closely associated with various metabolic disorders, such as gout, xanthinuria, and kidney stone. Therefore, the measurement of xanthine concentrations can serve as a valuable biomarker for assessing purine metabolic disorders, evaluating renal function, and monitoring oxidative stress. Various analytical methods, including spectroscopic techniques, chromatography, and electrochemical analysis, have been developed for the quantitative determination of xanthine. In particular, electrochemical methods offer advantages such as rapid analysis, simplicity, label-free, and non-destructive detection. In this study, we aimed to quantitatively analyze xanthine using a bio-nano hybrid composite electrode composed of xanthine oxidase and reduced graphene oxide/platinum nanoparticles. Finally, the developed bio-nano hybrid electrode-based xanthine sensor successfully achieved quantitative detection of xanthine over a wide linear range.
The performance of solid electrolytes in lithium-ion batteries is a critical factor for achieving high energy density and long-term stability. In this study, we aimed to enhance the electrochemical properties of polyethylene oxide (PEO)-based solid electrolytes by incorporating the metal-organic framework (MOF) UTSA-16(CoZn0.5). Through Brunauer-Emmett-Teller (BET) analysis, the optimal ratio of Co to Zn was determined, leading to the synthesis of UTSA-16(CoZn0.5 ). A solid electrolyte containing 1 wt% UTSA-16(CoZn0.5 ) (PLS1CZ) was subsequently fabricated. Electrochemical measurements revealed that PLS1CZ exhibited the highest lithium-ion transference number, along with superior ionic conductivity and structural stability under elevated temperatures. These enhancements are attributed to the ability of UTSA-16(CoZn0.5 ) to expand lithium-ion transport pathways and improve electrolyte-electrode interfacial stability. This work demonstrates the potential of UTSA-16(CoZn0.5 )-based PEO solid electrolytes to significantly advance the performance of next-generation lithium-ion batteries.
Electrolytes play a pivotal role across various electrochemical applications, including secondary batteries, supercapacitors, fuel cells, and electrochromic devices. Consequently, the development of novel electrolytes that simultaneously offer high ionic conductivity, excellent electrochemical stability, and environmental compatibility is essential for the realization of next-generation electrochemical systems. In this study, we synthesized a new type of ionic complex, K-C dot, based on polyanionic carbon dots and their counterion, K cations. We then applied this K-C dot as an electrolyte in an electrochromic system. Nanoscale carbon quantum dots form stable ionic complexes through electrostatic attraction and it-cation interactions with K cations. The K-C dot exhibits superior performance in the electrochromic properties of Prussian blue (PB) thin films compared to the conventional electrolyte, KCl. The PB thin film demonstrated a high coloration efficiency of 101.5 cm C and an excellent optical density change of 0.92. Furthermore, it maintained approximately 96% stability relative to its initial optical transmittance after 1,000 color switching cycles. Our research contributes new insights into the strategic design of electrolytes for electrochemical systems, with direct implications for the future development of electrolytes in both electrochromic devices and various energy storage and conversion technologies.
This study proposes a multi-output regression model for predicting the internal resistance of lithium-ion batteries across various states of charge(SOC), based on time-series data collected during the formation stage of the manufacturing process. The target resistance values were measured after aging using the Hybrid Pulse Power Characterization(HPPC) test. The input data consist of time-series measurements of voltage, current, and charge/discharge capacity recorded during formation, while the outputs correspond to internal resistance values at 24 SOC points ranging from 5% to 100%. The proposed regression models, based on XGBoost and Random Forest, achieved low mean errors of less than 1 m Omega and high coefficients of determination(R approximate to 0.99) across the entire SOC range without the need for additional pulse diagnostics. In particular, the model precisely predicted the internal resistance at 5% SOC-strongly correlated with battery lifespan-with a mean absolute percentage error of around 3%, demonstrating the feasibility of extracting early-life indicators using only charge/discharge data from the formation stage. By presenting a data-driven diagnostic approach that virtualizes the HPPC test, this work enables non-invasive estimation of internal resistance characteristics and offers practical applicability for battery lifespan prediction, quality screening, and process optimization.
With its high hydrogen density, storability, and ease of transportation, ammonia has emerged as a key candidate for both hydrogen storage and direct use as a carbon-free fuel in future carbon-neutral energy systems. Among various technologies, direct ammonia fuel cells (DAFCs), which operate without the need for upstream hydrogen reforming, are particularly promising due to their simplified system configuration and potential for enhanced energy efficiency by avoiding the energy-intensive process of hydrogen purification. Nevertheless, DAFCs operating under low-temperature conditions (similar to 100 C-omicron) face critical challenges, primarily stemming from the sluggish kinetics of the ammonia oxidation reaction (AOR) and the catalyst poising caused by the irreversible adsorption of nitrogen-based intermediates (N-ads and NOads ). At high-temperature conditions (700-900(omicron) C), however, the problem of the catalyst durability arises from nitridation and sintering during long-term operation. These issues significantly hinder power output and remain obstacles to practical deployment. This paper provides an overview of recent developments in catalysts and electrode materials aimed at addressing these limitations and proposes strategic approaches for electrode architecture and system design toward realizing high-performance direct ammonia anion exchange membrane fuel cells (DA-AEMFCs).
This paper analyzes patent trends in composite substrate technology for secondary batteries and presents strategies for future development. A total of 11,819 patents were collected and systematically analyzed, resulting in 543 valid patents. These patents were categorized by country, applicant, and technology to identify key trends. The study includes patents from Korea, United States, Japan, China, and Europe. Various polymer materials in composite current collectors were examined, including insulating types, cable-type batteries, conductive filler-containing materials, and fiber-based structures. The analysis revealed a sharp increase in patent filings since 2018, with Japan leading with 175 patents. However, after 2020, filings in the United States and China increased significantly. Among the top nine applicants, Japan and Korea each had four, while China had one, with Japanese companies primarily focusing on polymer materials with conductive fillers. PET was the most commonly used polymer due to its excellent properties and cost-effectiveness. Future advancements are expected to improve conductivity with conductive fillers and enhance safety with flame-retardant materials. Ultrasonic welding was the dominant tab connection method, showing excellent performance. This method may evolve by integrating with other welding techniques. Welding quality and electrical performance were identified as key factors, stressing the need for continued research.
Silicon monoxide (SiOx) has been considered a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and relatively better cycling stability compared to silicon (Si). In this study, SiO/X/M composites were synthesized via a simple sol-gel method using SiO, phenolic resin (Xylok, X), and melamine (Melamine, M). X-ray diffraction (XRD) and thermogravimetric analysis (TGA) confirmed that carbon and nitrogen components were introduced into the composite. In addition, the formation of a carbon-nitrogen coating layer on the surface was identified by X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS) attached to a scanning electron microscope (SEM). Electrochemical performance evaluation showed an initial discharge capacity of 1404 mAh g(-1) and an initial coulombic efficiency of 77.4%. After 60 cycles at a current density of 5 C, the composite retained 93% of its capacity, indicating improved cycling stability compared to SiO. Rate performance measured from 0.2 C to 10 C was also improved that of SiO.
Research on silicon monoxide (SiO) negative electrode materials for lithium-ion batteries has been actively pursued to enhance performance. In this study, we aimed to improve electrochemical performance by optimizing the electron transport pathways. The content of carbon black, as a conducting agent, was adjusted to vary the number of electron transport channels, and the resulting performance was compared. Additionally, two strategies were adopted. First, a 3D porous Cu foam was used as the current collector instead of flat Cu foil to provide macroscopic electron transport pathways. Second, a portion of carbon black was replaced with carbon nanotubes (CNTs) to develop microscopic electron transport pathways. These modifications were applied individually and simultaneously to fabricate and evaluate the electrodes. The results showed that increasing the carbon black content led to more electron transport channels, improving cycle performance and rate capability. Furthermore, the use of Cu foam and CNTs further enhanced performance. These findings demonstrate the establishment of efficient electron transport pathways without increasing the content of conductive additives, which could contribute to the commercialization potential of high-capacity negative electrodes in the future.
Energy harvesting technology provides an innovative solution for delivering self-sustaining power to wearable and implantable electronic devices. However, conventional energy harvesters face limitations when operating in electrolytic environments or at low motion speeds. To address these issues, a mechano-electrochemical energy harvester using carbon nanotubes has been developed. This technology induces changes in electrochemical double-layer capacitance through electrochemical ion movement, enabling operation within electrolytes and allowing applications across a range of fields, including wearable devices, implantable medical devices, and ocean monitoring systems. This environmentally friendly and sustainable energy solution is expected to play a crucial role in advancing future smart systems and wearable technologies.
