High-performance Electrode Research Articles

In situ construction of sea urchin-like structural NiCo-LDH coated cobalt‑nitrogen co-doped carbon as high-performance electrode for supercapacitor

Nickel‑cobalt layered double hydroxide (NiCo-LDH) has received much attention in the field of supercapacitor electrodes due to its multiple oxidation states and good electrochemical activity. However, NiCo-LDH often suffers from structural instability and low conductivity in practical applications. In this study, sea urchin-like structural NiCo-LDH coated cobalt‑nitrogen co-doped carbon (NiCo-LDH@Co-NC-x) electrode materials were prepared by in situ growth of NiCo-LDH on the surface of cobalt‑nitrogen co-doped carbon nanosheets (Co-NC) using a one-step hydrothermal method. The results show that the NiCo-LDH@Co-NC-2 electrode material exhibits excellent electrochemical performance, its specific capacitance is up to 1909 F g−1 at a current density of 1 A g−1, and capacitance retention of 69.5 % (only 26.2 % for NiCo-LDH) can be achieved after 10,000 cycles at a current density of 10 A g−1. This is because the abundant and uniformly distributed Co nanoparticles on Co-NC provide nucleation sites for the in-situ growth of NiCo-LDH, effectively improving the interface binding between Co-NC and NiCo-LDH, enhancing the structural stability of NiCo-LDH, and ensuring highly efficient electron transport throughout the NiCo-LDH@Co-NC-2 electrode. An asymmetric supercapacitor (NiCo-LDH@Co-NC-2//AC) was further assembled with NiCo-LDH@Co-NC-2 and activated carbon (AC) as positive and negative electrodes, respectively, achieving an energy density as high as 36.8 Wh kg−1 at a power density of 750 W kg−1. These findings suggest that the NiCo-LDH@Co-NC-2 composite can be a promising candidate for high-performance supercapacitor electrode.

Free-standing snowflake-like Mn-doped ZnO@CoCo2O4 nanofilm boosting cycle stability and energy density of supercapacitor

CoCo2O4 is considered as one of the most promising electrode materials owing to its inherently electrochemical performance and low cost. Nevertheless, the further practical application of CoCo2O4 as high-performance electrode material is hindered by its weak cycle stability. Herein, a free-standing snowflake-like Mn-doped ZnO@CoCo2O4 (MZCC) nanofilm is synthesized via hydrothermal method. The unique snowflake structure of this nanofilm composite exhibits obviously large specific surface area, thus promoting the redox reaction of the electrode material. The specific capacitance of the MZCC attains 1245F g−1 at 0.5 A/g. Furthermore, the assembled supercapacitor device with the MZCC and active carbon shows an energy density of 25.7 Wh kg−1 at a power density of 400 W kg−1. The device also demonstrated intriguingly outstanding cyclic stability, maintaining its original specific capacitance of 80.1 % after 3000 cycles at 2 A/g. This study delivers an effective method to construct high-performance free-standing metal oxide nanofilm electrodes for advanced supercapacitors.

Facile synthesis of KV3O8 nanobelts for solid-state supercapacitors

Electrochemical supercapacitors emerge as promising energy storage systems for various electronic applications owing to their low cost, safe operation, and long lifespan. However, the limited choice of cathode materials and lack of green and scalable synthesis strategies largely hinder their practical applications. Herein, we describe a facile ultrasonic-assisted chemical method for synthesizing potassium vanadate (KV3O8) nanobelt as cathode material for asymmetric supercapacitor application. It demonstrates excellent electrochemical performance in terms of high-rate capability, specific capacitance, operating voltage (1.8 V), and energy density (51 Wh kg−1). This work provides a new strategy for fabricating high-performance electrode material using a simple and low-cost ultrasonic-assisted chemical method which is highly efficient and suitable for large-scale production to develop advanced energy storage devices. By addressing the key challenges in the field, this study contributes to the advancement of sustainable and efficient energy storage solutions.

Defect-driven ion storage on hexagonal boron nitride for fire-safe and high-performance lithium-ion batteries

The mass market adoption of electric vehicles has increased the risk of safety concerns, such as overheating and flammability. Rational design of fire-safe and high-capacity anodes with thermal tolerance, capable of fast-charging and long cycle-life, is crucial for the development of next generation Li-ion batteries operating under extreme conditions. Here we report a defect engineered hexagonal boron nitride (hBN) anode to mediate the safety dilemma. We demonstrate that the defects generated via cryomilling catalyze the reversible LiF formation and enable the pseudocapacitive type Li-ion storage on hBN. The non-flammability and excellent thermal tolerance of hBN allows high specific capacity (880 mAh/g @ 25 mA/g), rate performance (480 mAh/g @ 5 A/g) and stable cycling (5000 cycles) at 60 °C. The Li-ion full-cell with the defective hBN anode and the conventional cathode (LiNiMnCoO2) delivers significantly higher energy (400 Wh kg−1) and power density (1 kW kg−1) when compared to graphite/LiNiMnCoO2 full-cells (121 Wh kg−1 and 250 W kg−1). First-principles calculations confirm that nitrogen antisite (NBVN) defects are responsible for the electrochemical activation of otherwise inactive hBN. The strategy of defect-induced electrochemical activation opens up new avenues in the design of high-performance electrode materials for numerous secondary batteries.

Controlled growth of redox-active polymer nanorods on MOF-derived activated nanoporous carbons: 3D reconstruction study and high-performance supercapacitor

Supercapacitors, which a energy storage systems, have been continuously studied because of their high power density and rapid charging-discharging capacity. Supercapacitors can be classified into pseudocapacitors and electric double-layer capacitors (EDLCs). The effective utilization of these two supercapacitor mechanisms is important for achieving high performance. In this study, highly nanoporous metal–organic framework (MOF)-derived carbon underwent chemical activation with potassium hydroxide to produce a high surface area. Subsequently, activated carbon was combined with a polyaniline (PANI) nanoarchitecture to introduce redox-active sites. Activated MOF-derived carbon provides a high specific surface area for EDLCs, and well-controlled PANI nanorods support large amounts of redox-active sites to achieve high capacitance. The aniline (ANI) concentration, growth time, acid, temperature, and ammonium persulfate (APS):ANI molar ratio were controlled to grow PANI nanorods without aggregation. At a scan rate of 5 mV/s, the capacitance of the PANI-ZIF-8-derived carbon composite reached 635.3 F/g, which was superior than that of ZIF-8-derived carbon (143.4 F/g). It also exhibited excellent durability during cycling, demonstrating that it can serve as a high-performance hybrid electrode material composed of carbon and polymer for supercapacitors.

Unveiling Intercalation Chemistry via Interference-Free Characterization Toward Advanced Aqueous Zinc/Vanadium Pentoxide Batteries.

Aqueous Zn/V2O5 batteries are featured for high safety, low cost, and environmental compatibility. However, complex electrode components in real batteries impede the fundamental understanding of phase transition processes and intercalation chemistry. Here, model batteries based on V2O5 film electrodes which show similar electrochemical behaviors as the real ones are built. Advanced surface science characterizations of the film electrodes allow to identify intercalation trajectories of Zn2+, H2O, and H+ during V2O5 phase transition processes. Protons serve as the vanguard of intercalated species, facilitating the subsequent intercalation of Zn2+ and H2O. The increase of capacity in the activation process is mainly due to the transition from V2O5 to more active V2O5·nH2O structure caused by the partial irreversible deintercalation of H2O rather than the increase of active sites induced by the grain refinement of electrode materials. Eventually, accumulation of Zn species within the oxide electrode results in the formation of inactive (Zn3(OH)2V2O7·2H2O) structure. The established intercalation chemistry helps to design high-performance electrode materials.

Incorporating Ag into Nd-Succinate MOF: Tunned electrochemical supercapacitor behaviour of Ag modified Nd-Succinate and electrochemical reaction mechanism

The electrode materials must be tailored to achieve higher energy and power densities and thus improve the supercapacitor's performance. This study explores the impact of incorporating Silver (Ag) into a Neodymium-Succinate Metal Organic Framework (Nd-Succinate) on supercapacitor behaviour. Initially, the Nd-Succinate MOF was characterized by structural, morphological, and spectroscopic characterizations. Subsequently, Ag/Nd-Succinate was synthesized and characterized. The electrochemical performance of Ag/Nd-Succinate was evaluated in a 6 M KOH electrolyte; the results indicated a significant enhancement in supercapacitor performance upon incorporating Ag into parent Nd-Succinate. From galvanostatic Charge-Discharge cycles (GCD), the capacitance for Ag/Nd-Succinate was determined to be 1389 F/g, i.e., 42 % higher than that of bare Nd-Succinate which was measured at 978 F/g. at a current density of 1.25 A/g. Ag/Nd-Succinate showcased an 89 % retention value for multiple retention cycles, slightly higher than the retention value obtained (84 %) for Nd-Succinate. The results of electrochemical experiments (Cyclic voltammetry (CV) and Electrochemical Impedance Spectra (EIS)) provided information about the nature of electron transfer and capacitance enhancement upon the introduction of Ag into Nd-Succinate. These findings provide valuable information on modifying MOFs and introducing metal that will help produce high-performance supercapacitor electrodes.

High-Performance p-type organic electrode materials with oxygen atoms as active centers enabled by molecular design and in situ electropolymerization

Redox-active organic molecules are considered to be one type of promising electrode materials for next generation lithium-ion batteries (LIBs), among which p-type electrode materials with higher voltage and outstanding reaction kinetics receive much attention. However, it is a great challenge to develop p-type materials with oxygen atom as the active center and the electrochemical performance of the few reported examples needs significant improvement. Herein, 1,3,5-tri(benzofuran-2-yl)benzene (TBFB) was elaborately designed and facilely synthesized through one-step Suzuki coupling reaction from commercially available raw reagents. When used as p-type electrode material for LIBs, it was found that TBFB with poor solubility can be effectively in situ electropolymerized during the charging process, forming more insoluble polymers. Experimental results demonstrate that TBFB electrode achieves a high specific capacity of 179.1 mAh g−1 and an ultralong cycle life of 8000 cycles. This work manifests the electrochemical performance of p-type organic electrode materials with oxygen atom as active center can be effectively enhanced by rational molecular design and in situ electropolymerization method.

Bulk scale synthesis of high-performance carbon nanomaterial from biogas plant residual waste: Tuned porosity and composition for advanced supercapacitor applications

Carbon based nanomaterials with tuned porosity and compositions are of great interest in terms of energy storing materials. Nevertheless, it is still a challenge to produce such nanostructures on a large scale in cost-effective manner. In this work, we demonstrate that carbon nanomaterial (CNM) can be prepared using biogas plant residual waste (BPRW) as the precursor on a bulk scale under the specific two step pyrolysis technique. The optimized process along with the catalyst used is crucial as the simple pyrolysis of precursor can only produce traditional activated carbon with significantly lower specific capacitance values. The spherical structure of silica nanoclusters and graphitic skeleton of synthesized CNM confirmed with the help of FE-SEM, AFM and HR-TEM along with Raman and XRD while EDX, XPS, and FT-IR studies confirm the presence of various functional groups along with their respective percentage composition. These CNMs show mesoporous structure of the nanomaterial. Among three different aqueous electrolytes, the maximum specific capacitance of 371.88 Fg−1 at 0.5 Ag−1 current density in 1 M H2SO4 indicates its suitability for the practical supercapacitor applications. The fabricated symmetric supercapacitor device using CNMs as the electrode material and 1 M H2SO4 as the electrolyte shows very good specific capacitance value with the high energy density of 34.4 Whkg−1 corresponding to 360 Wkg−1 power density along with the good cyclic stability over 10,000 cycles of charge–discharge. This innovative technique paves the way towards upcycling any lignin containing waste material into carbon-based nanomaterial on a bulk scale by an effective method, which can be further used as high-performance electrode material for energy storage applications like in supercapacitors and batteries.

Nickel-Copper Bimetallic Oxide Nanoparticles Prepared by Simple Coprecipitation Method as High Performance Electrode Materials for Asymmetric Supercapacitors.

Supercapacitors with transition bimetallic oxides as pseudocapacitive materials have been of wide concern for their excellent energy storage performance. In this work, a simple coprecipitation method was used to synthesize the precursor, followed by calcination to prepare Ni-Cu bimetallic oxide materials. The structure, morphology and properties of the materials prepared by different precipitating agents and different calcination temperatures of NCO-H2C2O4 precursor were investigated. The optimum precipitant was determined to be H2C2O4, and Ni-Cu nanoparticles with regular lamellar microstructure were obtained at the calcination temperature of 400 °C. The nanostructure and morphology provide a large active channel for the rapid diffusion of electrolyte ions, and the specific capacitance of NCO-H2C2O4-400 electrode material can reach 740.31 F/g Cs at 1 A/g. The investigation of charge storage mechanism shows that the contribution rate of capacitance and diffusion control is about 37.9% and 67.2%, respectively. The electrochemical test results of the asymmetric supercapacitors (ASC) constructed with NCO-H2C2O4-400 and activated carbon show that the specific capacitance, energy density, and power density of the capacitor are 52.66 F/g, 16.45 Wh/kg, and 759.51 W/kg, respectively. Even after 5000 charge/discharge cycles at 5 A/g, it can still keep 90.57% of its initial capacity. This work not only provides competitive electrode materials for energy storage devices but also provides a feasible strategy for producing complex transition metal oxide materials with high capacitance performance.

CZTS/phenylenediamine isomer nanocomposite electrodes for supercapacitor applications

This study delves into the potential of Cu2ZnSnS4 (CZTS) and its phenylenediamine (PDA) derivative-modified nanocomposites as eco-friendly electrodes in supercapacitors, intending to enhance capacitance values in energy storage systems. By integrating ortho (o-PDA), meta (m-PDA), and para (p-PDA) isomers into the CZTS framework, we have observed notable improvements in their electrochemical behavior. The physically bonded CZTS/p-PDA nanocomposites exhibited superior performance, achieving a specific capacitance of 424.6 F/g at a current density of 0.1 A/g and maintaining 95.5 % of this capacitance after 10,000 cycles, indicating excellent cyclic stability. Our research highlights the influence of PDA derivatives on the morphological, structural, and electrochemical characteristics of CZTS nanomaterials. These insights contribute to developing cost-effective, high-performing, and stable composite electrode materials for next-generation energy storage solutions. This work offers a significant step forward in identifying novel and sustainable nanomaterials for energy applications.

Porous carbon derived from center part of the corn cob for high-performance symmetrical supercapacitors

The central part of agricultural waste biomass corn cob was used as carbon precursor and KHCO3 as activating agent, and porous carbon materials were prepared by one-step carbonization method. The effect of KHCO3 on the structure and properties of porous carbon was studied. The results show that KHCO3 has an etching effect on porous carbon, and the greater the amount of KHCO3, the stronger the etching effect. The obtained biomass porous carbon material has abundant pores, reasonable pore size distribution and high specific surface area, which is conducive to ion transfer and charge storage. In addition, the heteroatom self-doping of porous carbon can improve surface hydrophilicity and generate additional pseudocapacitance, thereby improving its electrochemical properties. Electrochemical characterization shows that the porous carbon has a specific capacitor of up to 323 F g−1. The assembled symmetric supercapacitor (SSC) has an energy density of 20 Wh kg−1 at a power density of 350 W kg−1. This low-cost, high-performance electrode material has potential applications in high-power supercapacitors.

CoNi layered double hydroxides grown on Ag nanowires for high-efficient nitrate-to-ammonia conversion

Electrocatalytic reduction of nitrate to ammonia is a promising technology. The sluggish rate of the nitrate-to-nitrite reduction is the core issue. By reducing the energy barrier of this step, the reactivity can be greatly promoted. Here, we have documented Co2Ni1 layered double hydroxide (LDH) on Ag nanowire (NW) that demonstrates efficient catalytic activity in electro-reducing nitrate to ammonia under a diverse set of application conditions. It achieves a high ammonia yield (2.50 mmol h−l cm−2) and Faradaic efficiency (99.6 %) at −0.7 V versus a reversible hydrogen electrode (VRHE). Through comparative experiments, it has been proven that the selective reduction of nitrate to nitrite on Ag NW is the key. This series of Ag NW heterostructure electrodes provides new insights into the design principles of high-performance and high-durability nitrate reduction electrodes under environmentally relevant wastewater conditions.

Unusual electrochemical properties of boron and silicon Co-doped diamond electrodes

Boron-doped diamond (BDD) films exhibit exceptional physicochemical properties and have been utilized in numerous fields. As a common impurity in diamond, silicon is inevitably introduced into the diamond lattice during certain growth process. However, there are limited reports on the impact of silicon co-doping on the electrochemical properties of BDD electrodes. In this paper, we prepared a series of BDD electrodes with various silicon contents and made a systematic evaluation of these electrodes in terms of physicochemical properties. The results indicated that silicon and boron co-doped diamond (SiBDD) electrodes displayed a broader potential window and lower background current compared to the pure BDD electrode. Additionally, we observed that the electron transfer rate of the electrodes in the inner ([Fe(CN)6]3−/4−) redox systems exhibited a rising trend with increasing silicon content, whereas the electron transfer rate of the outer ([Ru(NH3)6]3+/2+) redox systems displayed contrasting trend. Surface analyses and electrochemical measurements results suggested that the unusual phenomena might stem from the alterations in surface functional groups and carrier density of the electrode inducing by silicon co-doping. In general, our results demonstrate, for the first time, that Si co-doping can influence the surface functional groups and carrier behavior of BDD electrodes, thereby altering the electrode's electrochemical performance. This provides new insights for the design of high-performance diamond electrodes.

Preparation and electrochemistry study of a new Ti-based PbO2 electrode with Ta-Ti-Sn(Ru)Ox interlayer in Cu electrowinning

Copper (Cu) is a crucial non-ferrous material, and in this research, a new composite layered anode, Ti/Ta-Ti-Sn(Ru)Ox/PbO2, was developed for the hydrometallurgical process. The anode was created using thermal decomposition and subsequent electrodeposition, with Ti serving as the matrix and Ta-Ti-Sn(Ru)Ox as the interlayer. The study identified that the optimal molar ratio of Ta:Ti was 4:1, the ideal number of coating layers was 3, and the preparation temperature was 550 °C. The addition of Sn element improved the bonding force of the coating, preventing it from detaching even if it fails, while the inclusion of Ru enhanced the electrode’s service life. Moreover, the deposited PbO2 layer demonstrated a rich porous structure. In a long-cycle copper electrodeposition application, anodes with optimal preparation parameters showed higher current efficiencies and reduced energy consumptions compared to the Ti/Sn-SbOx/PbO2 baseline electrode, energy consumption reduced by 220.8 kWh per ton of copper product. This research presents a valuable strategy for designing and constructing high-performance electrodes for nonferrous electrolysis and other similar applications.

NiCo layered double hydroxides/carbon dots composites with S-doing for high-performance asymmetric supercapacitors

The pursuit of high-performance electrode materials for supercapacitors has led to the exploration of transition metal layered double hydroxides (LDH), which boast an impressive theoretical specific capacitance. However, their intrinsic limitations, such as poor electronic conductivity and slow diffusion kinetics, have posed significant challenges for their practical implementation. In this work, a NiCo LDH/carbon dots (CDs) composite with S-doping has been meticulously designed to overcome the aforementioned limitations through a synergistic combination of heteroatom doping and carbon incorporation. Utilizing a one-pot hydrothermal method, the composite electrode for the application of asymmetric supercapacitors have been in-situ growth on Ni foam substrate, which not only serves as a robust support but also contributes to the formation of NiCo LDH by providing a uniform Ni source, thereby ensuring strong adhesion and structural integrity. The morphology and microstructures of composites could be finely modulated by adjusting CDs amount. With moderate CDs contents, the optimum electrode S-LDH/CDs-2 exhibits distinctive 3D needle-like spherical morphology, coupled with the ample space for ion diffusion. Consequently, the electrode demonstrates outstanding electrochemical performance, featuring a high areal capacitance of 5157 mF cm−2 at a current density of 2 mA cm−2. Additionally, it exhibits noteworthy rate performance and maintains excellent cycling stability. Integrating the innovative electrode into asymmetric supercapacitors configuration, superior energy density (0.24–0.45 mWh cm−2) and power density (4–20 mW cm−2) as well as good stability have been achieved for the S-LDH/CDs-2//AC device. These results indicate that S-doped NiCo LDH/CDs composite electrode has the desirable potential to be a candidate for energy storage devices.

Simple construction of molybdate anions-intercalated NiCo-based layered double hydroxides nanosheet arrays on carbon fibers for enhanced flexible fiber-shaped supercapacitors

As the energy supply devices for miniaturized, wearable, portable and intellectualized electronic products, flexible fiber-shaped supercapacitors (FSCs) have attracted great attention by virtue of their peculiar superiorities such as ultra-fast charge/discharge ability, ultra-high output power, ideal service life, outstanding mechanical flexibility, and superior compatibility with the human body. The performance enhancement of FSCs is highly dependent on the high-performance active electrode materials. In this work, a series of molybdate anions-intercalated NiCo based layered double hydroxides (NiCoMo-LDHs) have been synthesized on flexible carbon fiber (CF) by a simple electrodeposition strategy by regulating the Mo content and the growth time. It turns out that the intercalation of molybdate anions can significantly widen the interlayer spacing and reduce the crystallinity of the synthesized LDH materials. The morphological differences between the LDHs with different Ni/Co/Mo ratios are analyzed, and the morphological evolution process of the materials with the specific Ni/Co/Mo ratio of 1:3:0.2 are systematically investigated. The well-developed NiCoMo-LDH nanosheets electrode with appropriate Ni/Co/Mo ratio (NCM2–500) delivers the best electrochemical performances among all the synthesized LDHs. In particular, the synthesized NCM2–500 fiber electrode exhibits excellent specific capacitance, superior electrical conductivity and favourable cycling stability. Additionally, the assembled parallel type NCM2–500//AC FSC device using NCM2–500 and activated carbon (AC) as the cathode and anode with the assistance of PVA/KOH gel electrolyte demonstrates a brilliant specific energy of 36 Wh cm−1 at 845 W cm−1 (nearly 17 Wh kg−1 at about 400 W kg−1) and a high cycle lifespan of maintaining 103 % of the pristine capacity after 5000 cycles. This FSC device is an ideal candidate for next-generation applications due to its remarkable electrochemical properties.

A thiophene-sulfur doping porous organic Polymer/reduced graphene oxide composite for high-performance supercapacitor electrode

Porous organic polymers (POPs) are a type of promising materials which can be used in energy storage devices. In this study, we synthesized a novel thiophene-sulfur doping POPTAB-TPDA through Schiff-base condensation reaction between 1,3,5-triaminobenzene (TAB) and 2,5-thiphenedialdehyde (TPDA) at ambient temperature and pressure. With the reduced graphene oxide (rGO) as a template, thiophene-sulfur doping POPTAB-TPDA-rGO composite was obtained by in-situ synthesis under the same condition. As supercapacitor active electrode material, the stable value of specific capacitance of the POPTAB-TPDA-rGO composite (232.4 F g−1) is higher than that of pristine POPTAB-TPDA (193.5 F g−1) at a current density of 0.5 A g−1. The assembled asymmetric supercapacitor utilizing POPTAB-TPDA-rGO composite as positive material has an energy density of 38.7 W h kg−1 with the power density of 1619.2 W kg−1, displaying a better result than POPTAB-TPDA-based device. Furthermore, the POPTAB-TPDA-rGO-based supercapacitor exhibits an excellent cycle duration, with 81.7 % retention of its highest capacitance after 7000 cycles. This superior electrochemical performance of the composite could be attributed to three aspects: the reversible redox reaction processes of thiophene-sulfur units, the porous structure of POPTAB-TPDA facilitating ion transmission, and the good electron conductivity of rGO template.

Selecting optimal carbon inks for fabricating high-performance screen-printed electrodes for diverse electroanalytical applications

Carbon-based screen-printed electrodes (SPEs) are extensively employed in electrochemistry due to their reproducibility, low-cost production, disposability and versatility. It is commonly accepted that batch to batch variations may occur due to variations in the ink formulation or the use of a different ink to print the electrodes. In this paper, three different commercial carbon-based inks (DuPont, Loctite and SunChemical) were used to manufacture SPEs, referred to respectively as Dup-SPE, Loc-SPE and Sun-SPE, using a semi-automated screen-printing technology. This study focuses on evaluating the quality, characteristics and electrochemical performance of the fabricated SPEs. Furthermore, the study aimed to investigate potential correlations between the ink composition and the nature of different target molecules, as well as their electroanalytical responses. Specifically, phenolic compounds and cocaine cutting agents are tested in alkaline conditions, while benzodiazepines and cephalosporine antibiotics are investigated in acidic media using square wave voltammetry (SWV). This aims to extract insights for the proper selection of inks and SPEs in both conditions. Additionally, a scan rate study of cephalosporine antibiotics using linear sweep voltammetry (LSV) is performed confirming the ion-exchange polymer layer on the electrode surface of Loc-SPE, which impact surface and electrochemical properties, leading to drawbacks in alkaline SWV sensing, but strategic benefits in reductive sensing resulting in an enhanced selective detection of specific targets. The insights on ink-specific influences on the surface and electrochemical properties of the SPEs obtained, may be useful for facilitating the electrode selection in diverse electrochemical applications, emphasizing the critical role of ink composition in achieving desired sensing capabilities.

Soft, Multifunctional MXene-Coated Fiber Microelectrodes for Biointerfacing.

Flexible fiber-based microelectrodes allow safe and chronic investigation and modulation of electrically active cells and tissues. Compared to planar electrodes, they enhance targeting precision while minimizing side effects from the device-tissue mechanical mismatch. However, the current manufacturing methods face scalability, reproducibility, and handling challenges, hindering large-scale deployment. Furthermore, only a few designs can record electrical and biochemical signals necessary for understanding and interacting with complex biological systems. In this study, we present a method that utilizes the electrical conductivity and easy processability of MXenes, a diverse family of two-dimensional nanomaterials, to apply a thin layer of MXene coating continuously to commercial nylon filaments (30-300 μm in diameter) at a rapid speed (up to 15 mm/s), achieving a linear resistance below 10 Ω/cm. The MXene-coated filaments are then batch-processed into free-standing fiber microelectrodes with excellent flexibility, durability, and consistent performance even when knotted. We demonstrate the electrochemical properties of these fiber electrodes and their hydrogen peroxide (H2O2) sensing capability and showcase their applications in vivo (rodent) and ex vivo (bladder tissue). This scalable process fabricates high-performance microfiber electrodes that can be easily customized and deployed in diverse bioelectronic monitoring and stimulation studies, contributing to a deeper understanding of health and disease.