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Transition-metal selenides have been extensively studied as promising electrode materials for supercapacitors. Engineering amorphous/crystalline heterostructures is an effective strategy to improve rich active sites for accelerating redox reaction kinetics but still lacks exploration. In this study, an amorphous/crystalline heterostructure was designed and constructed by selenizing the self-sacrificial template NiMnS to generate amorphous Mn/polycrystalline Ni0.85Se–NiSe2 heterophase via the phase transformation from metal sulfide into metal selenide. The synergy of the complementary multi-components and amorphous/polycrystalline heterophase could enrich electron/ion-transport channels and expose abundant active sites, which accelerated electron/ion transfer and Faradaic reaction kinetics during charging/discharging. As expected, the optimal NiMnSe exhibited a high specific charge (1389.1 C g−1 at 1 A g−1), a good rate capability, and an excellent lifespan (88.9% retention). Moreover, the fabricated NiMnSe//activated carbon device achieved a long cycle life and energy density of 48.0 W h kg−1 at 800 W kg−1, shedding light on the potential for use in practical applications, such as electrochemical energy-storage devices. [ABSTRACT FROM AUTHOR]

Very recently, open-cage metallo-azafullerenes PbC100N4H4 and Pb2C100N4H4 containing one Pb–N4–C moiety have been synthesized via the electron beam. Herein, we utilized density functional theory calculations in combination with ab initio molecular dynamics (AIMD) simulations to study the geometric and electronic structures, bonding properties, thermodynamic stability, and catalytic performance of MC100N4H4 and M2C100N4H4 (M = Ge, Sn, Pb). Metal–nitrogen distances and metal–metal distances increase along with the metal radius while the metal atom is positively charged. Energy decomposition analysis revealed that the bonding interactions between M and the C100N4H4 fragment could be described as the donor–acceptor interaction between M(ns0(n−1)d10np4) and C100N4H4 fragment, in which the orbital interactions terms contribute more than the electrostatic interactions. AIMD simulations demonstrate that those metallo-azafullerenes exhibit thermodynamic stability at room temperature. These metallo-azafullerenes, which could serve as typical carbon-supported single-atom catalysts, possess enhanced catalytic performance toward the oxygen reduction reaction (ORR) compared to the planar catalysts, which is attributed to the curvature of metallo-azafullerenes. GeC100N4H4 and SnC100N4H4 exhibit high catalytic performance in the 4e-ORR pathway to H2O, whereas only PbC100N4H4 is suitable for the 2e-ORR reaction pathway because of the difficulty in obtaining electrons. All M2C100N4H4 favors the 4e-reaction pathway due to the presence of the axial metal atom. Our finding of open-cage metallo-azafullerenes as efficient single-atom catalysts holds profound implications for both fundamental research in catalysis and practical applications in fuel cells and other electrochemical devices. [ABSTRACT FROM AUTHOR]

Graphene/stainless steel (SUS) structures have received attention as an approach to enhancing the performance of SUS in various applications, such as energy storage and electrochemical devices. Despite many studies, the synthesis of graphene nanostructures with controllable growth orientation on SUS remains challenging. The present work demonstrates the selective synthesis of monolayer to bilayer graphene and vertical graphene (i.e., carbon nanowalls) on SUS by plasma enhanced chemical vapor deposition and also explains the associated growth mechanisms. This study indicates that the graphene nucleation density can be tuned by varying the growth temperature and CH4/H2 ratio during synthesis. It is also evident that graphene growth occurs within a mixed phase of γ-Fe and Fe3C at high temperatures, and a high carbon supply of above 900 °C triggers the transition of growth orientation from planar to vertical. [ABSTRACT FROM AUTHOR]

Prototyping analytical devices with three-dimensional (3D) printing techniques is becoming common in research laboratories. The attractiveness is associated with printers' price reduction and the possibility of creating customized objects that could form complete analytical systems. Even though 3D printing enables the rapid fabrication of electrochemical sensors, its wider adoption by research laboratories is hindered by the lack of reference material and the high "entry barrier" to the field, manifested by the need to learn how to use 3D design software and operate the printers. This review article provides insights into fused deposition modeling 3D printing, discussing key challenges in producing electrochemical sensors using currently available extrusion tools, which include desktop 3D printers and 3D printing pens. Further, we discuss the electrode processing steps, including designing, printing conditions, and post-treatment steps. Finally, this work shed some light on the current applications of such electrochemical devices that can be a reference material for new research involving 3D printing. [ABSTRACT FROM AUTHOR]

Constructing low-cost, high-catalytic-performance anode electrocatalysts is a significant challenge for methanol oxidation (MOR) and urea oxidation (UOR) reactions. Using paper templates with abundant pores to prepare thin porous metal materials helps to obtain high-performance electrode materials. The nano amorphous B-doped Ni/crystalline Ni (nanoam Ni-B/Ni) foil composite electrodes were derived from paper templates prepared by impregnation, high-temperature reduction, and electrodeposition methods. Porous Ni foils (Nip) derived thinnest rice ("Xuan") paper, initially used for Chinese calligraphy and painting, exhibits the best performance due to its strong adsorption and wettability. Compared to direct current electrodeposition, pulse electrodeposition yields finer amorphous B-doped Ni nanoparticles with good catalytic performance. Under a current density of 100 mA·cm−2, the nanoam Ni-B/Ni composite electrode prepared under a duty cycle of 0.5–1.0 s achieved current densities of 290.4 mA·cm−2 (MOR) and 340.4 mA·cm−2 (UOR) at 0.8 V, which are improved by 37.1% and 55.1%, respectively, compared to those of Nip. After 2000 cycles, with solution replacement, the current densities maintained 99.2% (MOR) and 81.6% (UOR) of the original values, showing excellent electrocatalytic stability. This research provided a new use for Chinese rice paper, and the prepared Nip-based electrode, with a thickness of about 60 μm and a low area quality, had a simple preparation process and good electrochemical properties, and can be used as a potential substitute for commercial Ni foam for portable or small electrochemical devices. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) over perovskite oxides, upon undergoing a lattice oxygen oxidation mechanism, is strongly oxygen vacancy‐correlated as determined by the oxygen ion diffusivity. Despite substantial efforts having been devoted to tuning the oxygen vacancy concentration in perovskite oxides, the impact of the concomitant altering of oxygen vacancy ordering is often underestimated. In particular, the underlying mechanism of how the ordering and the concentration of oxygen vacancy affect the lattice OER, and how to well balance them still remain inadequately understood. Herein, a series of Sr1−xCaxCo0.5Fe0.5O3−δ with gradually increased oxygen vacancy concentration and ordering are synthesized. Theoretical calculations indicated that a higher oxygen vacancy concentration promoted the lattice oxygen migration, whereas a higher oxygen vacancy ordering impeded it. Particularly, Sr0.5Ca0.5Co0.5Fe0.5O3−δ with a relatively higher oxygen vacancy concentration and a lower ordering displayed the maximum oxygen diffusion rate and the optimal OER activity, affording a current density of 10 mA cm−2 at a quite low overpotential of 310.2 mV, together with a small Tafel slope of 55.87 mV dec−1. This study sheds light on the critical influence of oxygen vacancy configuration on the lattice OER, and paves a compromised avenue to screen and design advanced electrocatalysts for various electrochemical devices. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have emerged as promising materials for ion conduction due to their highly tunable structures and excellent electrochemical stability. This review paper explores the mechanisms of ion conduction in COFs, focusing on how these materials facilitate ion transport across their ordered structures, which is crucial for applications such as solid electrolytes in batteries and fuel cells. We discuss the design strategies employed to enhance ion conductivity, including pore size optimization, functionalization with ionic groups, and the incorporation of solvent molecules and salts. Additionally, we examine the various applications of ion-conductive COFs, particularly in energy storage and conversion technologies, highlighting recent advancements and future directions in this field. This review paper aims to provide a comprehensive overview of the current state of research on ion-conductive COFs, offering insights into their potential to design highly ion-conductive COFs considering not only fundamental studies but also practical perspectives for advanced electrochemical devices. [ABSTRACT FROM AUTHOR]

Multi‐walled carbon nanotubes (MWCNTs) with excellent physiochemical properties have been recently applied to energy/power generation and storage systems encompassing polymer electrolyte membrane fuel cells (PEMFCs). However, there is a lack of investigations of the properties of MWCNT composites themselves under the actual operating conditions of systems. In this paper, MWCNTs/polytetrafluoroethylene (PTFE) composites were fabricated as electric and hydrophobic components for energy/power systems. The electrical properties, heating behavior, hydrophobicity, and water evaporation behavior of the composites are characterized within the operating voltage ranges of PEMFC. With 50% MWCNT content, the conductivity and the contact angle were 11.83 S/cm, and the contact angle 128.1°, respectively. The MWCNT/PTFE composite film showed a linear temperature rise with voltages and rapid temperature saturation within 40 s. The rate in the initial heating range was measured at 0.5°C/s for the voltage of 0.5 V. The voltage increase induced an exponential decrease in the height of water droplets on the composite surface. The evaporation rate increased almost 10‐fold, from 0.013 mm/min at 0.0 V to 0.12 mm/min at 1.0 V. The proposed characteristics of the functional composite provide insights into the material requirements for electrochemical devices, including PEMFC. Highlights: Multi‐walled carbon nanotube/polytetrafluoroethylene composites can be applied to energy storage and power generation.Key properties of the composites are proposed for polymer electrolyte membrane fuel cell (PEMFC) operating conditions.The composite has a fast heating by high conductivity and temperature uniformity.Water‐vapor transformation under PEMFC operating voltage is quantified. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The recent discovery of SrSn 0.8 Sc 0.2 O 3- δ (SSS) perovskite oxide as a promising proton-conducting material has generated interest in its potential application in electrochemical devices as PCFCs. This study assesses the feasibility of SSS in PCFCs by its stability, density, chemical compatibility, and electrochemical performance. The study demonstrated the favorable stability of SSS even after reduction at 800 °C under H 2 for 24 h as well as immersion in boiling water for 5 h. The relative density of SSS could easily exceed 94% after sintering with NiO aid at 1400 °C. The chemical compatibility and electrochemical performance of SSS were investigated with various electrode materials. The BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3- δ exhibited relatively better electrochemical performance with SSS. The electrolyte was co-sintered with a Ni-based anode substrate and densified to high density at 1450 °C without sintering aids. The fuel cell utilizing an anode-supported Ni-SSS|SSS|BCFZY-SSS configuration exhibited a peak power density of 432.1 mW cm−2 at 800 °C. • New proton conductor SSS is expected to replace conventional Ba-based proton conductor. • The SSS exhibits excellent sintering activity and chemical stability. • The SSS has good chemical compatibility with most electrode materials. • A dense SSS electrolyte membrane (∼10μm) can be obtained by sintering at 1450 °C. • The SSS-based PCFC with an anode-supported structure exhibits a high power density of 432.1 mW cm−2. [ABSTRACT FROM AUTHOR]

The rate performance, power density, and energy efficiency of electrochemical devices are often limited by ionic conductivities in electrolyte and electrode materials. Framework Prussian blue analogs and dense niobium oxides have been identified as high‐rate electrodes for sodium‐ and lithium‐ion batteries, respectively, yet the origin of the extremely high solid‐state Na+/Li+ transport is not fully understood. Of critical importance is the fact that their ultra‐low activation energy and anomalous pre‐exponent factor cannot be satisfactorily rationalized from conventional theory of solid‐state diffusion in the crystal lattice. Here, assisted by density‐functional‐theory calculations, we argued that the true origin is a unique surface‐like diffusion mechanism of the intercalation ions. In a surface‐like migration event, a mobile ion moves along the channel wall via a low coordination number and low migration barrier experiencing minimal steric hindrance. It is similar to surface diffusion in the conventional picture and contrasts with lattice diffusion from one interstitial/vacancy site to another one with high coordination number, crowded saddle‐point geometry and high migration barrier. We found that the shifting from solid‐state lattice diffusion to surface‐like diffusion is determined by the size difference between the mobile ion and the diffusion channel, and a lowest migration energy barrier can be reached by mediating the channel size. The analogy to gas diffusion in molecular sieves shall be discussed. Additionally, the effects of defects and crystal water in Prussian blue analogs were also discussed for better understanding their rate performances in experimental scenarios. [ABSTRACT FROM AUTHOR]

The symmetric solid oxide electrolysis cell (SSOEC) is an advanced electrochemical device that can convert electricity into chemical energy in an efficient and environmentally friendly manner. However, the development of SSOEC is still limited by competent and reliable electrode materials. Herein, the perovskite-type oxide electrode materials La 0 · 7 Sr 0 · 3 Fe 0 · 9 Ni 0 · 1 O 3-δ (LSFN) and La 0 · 55 Ce 0 · 15 Sr 0 · 3 Fe 0 · 9 Ni 0 · 1 O 3-δ (LCSFN) were investigated. Compared with the LSFN symmetric cell, the current density of LCSFN increased from 0.355 A cm−2 to 0.519 A cm−2 under the condition of CO 2 electrolysis at 800 °C and 1.5 V, and the polarization resistance (Rp) decreased from 4.59 Ω cm2 to 2.35 Ω cm2, indicating that the electrocatalytic activity of the electrode was improved after Ce doping. Furthermore, the composite with Gd 0.1 Ce 0 · 9 O 2- δ (GDC) can increase the three-phase boundary of the electrode, thus increasing the reaction active site and improving the cell performance. At 800 °C and 1.5 V, the LCSFN-GDC composite electrode showed better performance in CO 2 electrolysis. The current density further increased to 0.765 A cm−2 compared to the LCSFN symmetric cell. More importantly, the electrolysis cell maintains good stability for 25 h at 700 °C. The results demonstrate that both Ce doping and GDC composite are well-established methods for enhancing the electrode performance of SSOEC. • La 0 · 7 Sr 0 · 3 Fe 0 · 9 Ni 0 · 1 O 3-δ (LSFN) and La 0 · 55 Ce 0 · 15 Sr 0 · 3 Fe 0 · 9 Ni 0 · 1 O 3-δ (LCSFN) as SSOEC electrode was explored. • SSOEC reaches a high current density of 0.765 A cm−2 at 800 °C and 1.5 V for CO 2 electrolysis. • SSOEC shows good stability at 700 °C at thermal-neutral voltage. • Ce doping and GDC composite are well-established methods for enhancing the electrode performance of SSOEC. [ABSTRACT FROM AUTHOR]

A solid oxide fuel cell (SOFC) is a clean and very efficient electrochemical conversion device, which generates electricity directly from fuel electrochemical oxidation. In this paper, a three dimensional numerical model has been developed in order to analyse the role of some thermophysical and morphological parameters on the performance of the SOFC cell. In particular, we studied the effect of the variation of permeability of the electrodes: fuel distribution, ionic and electric current density, pressure and diffusion flux are analyzed and compared. The volume fraction of the ionic and electronic phase in the electrodes is studied using a parametric study. It was shown that the current density enhanced by decreasing the permeability, up to a defined value, and it diminished with very small permeability. A remarkable influence of pressure and diffusion of species on the performance of the cell, with the variation of permeability, has been recognized. Varying the permeability in the active layer of electrodes has a large impact on the current density, connected to the volume fraction of ionic phase. This study permits to comprehend the relationship between the performance and microstructure of SOFCs. Meanwhile, it furnishes theoretical guidance for an optimum design of the electrode permeability. • A three-dimensional model of a single SOFC is developed using CFD method. • Varying the permeability of electrode components affects the cell performance. • The impact of volume fractions for different permeabilities is studied. • It is concluded that there is an optimum design of the electrode permeability. [ABSTRACT FROM AUTHOR]

The surging demand for sustainable energy has spurred intensive research into electrochemical conversion devices such as fuel cells, water splitting, and metal‐air batteries. The performance of oxygen electrocatalysts significantly impacts overall electrochemical efficiency. Recently, spinel oxides (AB2O4) have emerged as promising candidates; however, the scarcity of prior studies underscores the need for a thorough and comprehensive exploration. This study presents a computational framework that integrates machine learning and density functional theory (DFT) calculations for the systematic screening of 1240 spinel oxides. The data scarcity is addressed while enhancing prediction accuracy. Selected candidates are identified to outperform the benchmarking perovskite oxide. Additionally, their potential as mixed ionic and electronic conductors with a 3D network of ion diffusion pathways is highlighted. To further enhance the understanding and prediction of stability, catalytic activity, and reaction mechanisms, a new undemanding descriptor is introduced: the covalency indicator. This study offers a design principle for the development of high‐performance spinel oxide oxygen electrocatalysts. [ABSTRACT FROM AUTHOR]

The ability to perform both electrochemical and structural/elemental characterization in the same experiment and at the nanoscale allows to directly link electrochemical performance to the material properties and their evolution over time and operating conditions. Such experiments can be important for the further development of solid oxide cells, solid‐state batteries, thermal electrical devices, and other solid‐state electrochemical devices. The experimental requirements for conducting solid‐state electrochemical TEM experiments in general, including sample preparation, electrochemical measurements, failure factors, and possibilities for optimization, are presented and discussed. Particularly, the methodology of performing reliable electrochemical impedance spectroscopy measurements in reactive gases and at elevated temperatures for both single materials and solid oxide cells is described. The presented results include impedance measurements of electronic conductors, an ionic conductor, and a mixed ionic and electronic conductor, all materials typically applied in solid oxide fuel and electrolysis cells. It is shown that how TEM and impedance spectroscopy can be synergically integrated to measure the transport and surface exchange properties of materials with nanoscale dimensions and to visualize their structural and elemental evolution via TEM/STEM imaging and spectroscopy. [ABSTRACT FROM AUTHOR]

Voltammetry, which is at the core of electroanalytical chemistry, is an analytical method that investigates and evaluates the current-potential relationship obtained at a given working electrode. If it is used dropping mercury as working electrode, the method is called as polarography. The current year 2022 marks the 100th anniversary of the discovery of polarography by Czech Jaroslav Heyrovský. He received the Nobel Prize in Chemistry in 1959 for this discovery and his contribution to the scientific world. A hundred years, within the endless existence of the universe is maybe nothing. A hundred years, in the history of mankind is a line, maybe a short paragraph. But, in science, a hundred years can lead to very significant advances in a field and often to the birth and establishment of an entirely new scientific discipline. Indeed, in the last hundred years, the design and use of new electrochemical devices, depending on the progress in microelectronics and computer technologies, has almost revolutionized voltammetry. Besides these developments, due to the fact that the redox (oxidation/reduction) process is very basic for living organisms; the voltammetry, especially with the beginning of the 21st century, has started to be used as a very powerful tool in neuroscience to solve the mystery of the brain (the basic problems of biomolecules with physiological and genetic importance in brain tissue). This review article is an overview of the 100-year history and fascinating development of voltammetry from Heyrovský to the present. [ABSTRACT FROM AUTHOR]

Carbon‐based allotropes are propelling a technological revolution in communication, sensing, and computing, concurrently challenging fundamental theories of the previous century. Nevertheless, the demand for advanced carbon‐based materials remains substantial. The crux lies in the efficient and reliable engineering of novel carbon allotrope. Although C18 has undergone theoretical and experimental investigation for an extended period, its preparation and direct observation in the condensed phase occurred only recently through STM/AFM techniques. The distinctive cyclic ring structure and the dual 18‐center π delocalization character introduce various uncommon properties to C18, rendering it a subject worthy of in‐depth exploration. In this context, this review delves into past developments contributing to the state‐of‐the‐art understanding of C18 and provides insights into how future endeavours can expedite practical applications. Encompassing a broad spectrum, this review comprehensively investigates almost all facets of C18, including geometric characteristics, electron delocalization, bonding nature, aromaticity, reactivity, electronic excitation, UV/Vis spectrum, intermolecular interaction, response to external fields, electron affinity, ionization, and other molecular properties. Moreover, the review also outlines representative strategies for the direct synthesis and characterization of C18 using atom manipulation techniques. Following this, C18‐based complexes are summarized, and potential applications in catalysis, electrochemical devices, optoelectronics, and sensing are discussed. [ABSTRACT FROM AUTHOR]

Electrochemical devices allow the conversion and storage of renewable energy into high‐value chemicals to mitigate carbon emissions, such as hydrogen production by water electrolysis, carbon dioxide reduction, and the electrochemical synthesis of ammonia. Independent regulation of the electrode pH environment is essential for optimizing the electrode reaction kinetics and enriching the catalyst species. The in situ water dissociation (WD, H2O→H++OH−${{{\mathrm{H}}}_2}{\mathrm{O}} \to {{{\mathrm{H}}}^ + } + {\mathrm{O}}{{{\mathrm{H}}}^ - }$) in bipolar membranes (BPMs) offers the possibility of realizing this pH adjustment. Here, the design principles of high‐performance polymeric BPMs in electrochemical device applications are presented by analyzing and connecting WD principles and current–voltage curves. The structure–transport property relationships and membrane durability, including the chemical and mechanical stability of the anion‐ and cation‐exchange layers as well as the integrality of the interfacial junction, are systematically discussed. The advantages of BPMs in new electrochemical devices and major challenges to break through are also highlighted. The improved ion and water transport in the membrane layer and the minimized WD overpotential and ohmic loss at high current densities are expected to facilitate the promotion of BPMs from conventional chemical production to novel electrochemical applications. [ABSTRACT FROM AUTHOR]

Electrochemical descaling devices have been widely used in the industrial field due to their broad applicability, convenience of operation, and cost-effectiveness. However, there are many factors that affect the descaling performance of electrochemical descaling devices, such as the selection of electrode materials, the shape and layout of the anode and cathode, the voltage and current of electrochemical equipment, the flow rate, temperature, and mineral content. Existing research has primarily focused on the influence of electrode materials and current density on descaling efficiency, while neglecting external factors such as water flow rate and temperature. In order to further explore the internal and external factors affecting the descaling performance of descaling machines, this study constructed an experimental platform for a descaling machine fouling device. Different voltages, currents, water flow rates, and temperatures were studied to assess the descaling efficiency of the descaling machine. The results indicated that under the conditions of a temperature of 30 °C, a flow rate of 0.35 m/s, a voltage of 24 V, and a current of 10 A, the fouling resistance effect of the electrochemical descaling device was optimal. This provides a new perspective for further improving the descaling efficiency of descaling machines and conducting parameter optimization. [ABSTRACT FROM AUTHOR]

To achieve carbon neutrality and sustainable development, innovative solar‐to‐fuel systems have been designed through the integration of solar energy harvesting and electrochemical devices. Over the last decade, there have been notable advancements in enhancing the efficiency and durability of these solar‐to‐fuel systems. Despite the advancements, there remains significant potential for further improvements in the performance of systems. Enhancements can be achieved by optimizing electrochemical catalysts, advancing the manufacturing technologies of photovoltaics and electrochemical cells, and refining the overall design of these systems. In the realm of catalyst optimization, the effectiveness of materials can be significantly improved through active site engineering and strategic use of functional groups. Similarly, the performance of electrochemical devices can be enhanced by incorporating specific additives into electrolytes and optimizing gas diffusion electrodes. Improvements in solar harvesting devices are achievable through efficient passivant and self‐assembled monolayers, which enhance the overall quality and efficiency of these systems. Additionally, optimizing the energy conversion efficiency involves the strategic use of DC converters, photoelectrodes, and redox media. This review aims to provide a comprehensive overview of the advancements in solar‐powered electrochemical energy conversion systems, laying a solid foundation for future research and development in the field of energy sustainability. [ABSTRACT FROM AUTHOR]

The integration of electrochromic devices and energy storage systems in wearable electronics is highly desirable yet challenging, because self‐powered electrochromic devices often require an open system design for continuous replenishment of the strong oxidants to enable the coloring/bleaching processes. A self‐powered electrochromic device has been developed with a close configuration by integrating a Zn/MnO2 ionic battery into the Prussian blue (PB)‐based electrochromic system. Zn and MnO2 electrodes, as dual shared electrodes, the former one can reduce the PB electrode to the Prussian white (PW) electrode and serves as the anode in the battery; the latter electrode can oxidize the PW electrode to its initial state and acts as the cathode in the battery. The bleaching/coloring processes are driven by the gradient potential between Zn/PB and PW/MnO2 electrodes. The as‐prepared Zn||PB||MnO2 system demonstrates superior electrochromic performance, including excellent optical contrast (80.6%), fast self‐bleaching/coloring speed (2.0/3.2 s for bleaching/coloring), and long‐term self‐powered electrochromic cycles. An air‐working Zn||PB||MnO2 device is also developed with a 70.3% optical contrast, fast switching speed (2.2/4.8 s for bleaching/coloring), and over 80 self‐bleaching/coloring cycles. Furthermore, the closed nature enables the fabrication of various flexible electrochromic devices, exhibiting great potentials for the next‐generation wearable electrochromic devices. [ABSTRACT FROM AUTHOR]

Glycol sidechains are often used to enhance the performance of organic photoconversion and electrochemical devices. Herein, we study their effects on electronic states and electronic properties. We find that polymer glycolation not only induces more disordered packing, but also results in a higher reorganisation energy due to more localised π-electron density. Transient absorption spectroscopy and femtosecond stimulated Raman spectroscopy are utilised to monitor the structural relaxation dynamics coupled to the excited state formation upon photoexcitation. Singlet excitons are initially formed, followed by polaron pair formation. The associated structural relaxation slows down in glycolated polymers (5 ps vs. 1.25 ps for alkylated), consistent with larger reorganisation energy. This slower vibrational relaxation is found to drive ultrafast formation of the polaron pair state (5 ps vs. 10 ps for alkylated). These results provide key experimental evidence demonstrating the impact of molecular structure on electronic state formation driven by strong vibrational coupling. Glycol sidechains are often used to enhance the performance of organic photoconversion and electrochemical devices. Here, the authors provide photophysical insight into the role of glycol sidechains for the formation of polaron pairs induced by strong vibrational coupling. [ABSTRACT FROM AUTHOR]

Transition metal‐based materials exhibit a broad range of catalytic activities in numerous electrochemical processes. Their displayed catalytic functions rely essentially on their distinctive electronic structures, changes of which play pivotal roles in dictating reaction dynamics within many electrochemical devices. Nevertheless, accurately probing electronic structure changes, especially in real‐time, of active materials remains a formidable challenge. In this work, a viable approach to achieve it within a CoC2O4/Li model system by employing a combined microscopic is demonstrated, spectroscopic analysis, plus a unique operando magnetometry technique. The findings reveal that upon completion of the conventional conversion of CoC2O4, a surface‐dominated capacitance emerges at the Co/Li2C2O4 interface owing to the injection of spin‐polarized electrons. Subsequently, the decomposition of Li2C2O4 proceeds through the releasing of the spin‐polarized electrons from Co, which, therefore serve as a catalyst leading to further discharge products. Such real‐time monitoring of electron transfer is realized by in situ monitoring electronic structure changes of Co, manifested by its intriguing magnetization alterations during the process. This work highlights a novel characterization tool that provides a solid explanation for the commonly observed large capacities in this type of materials and sheds light on design rules and selection guidance of materials for high‐performance electrochemical energy storage systems. [ABSTRACT FROM AUTHOR]

Redox‐conducting polymers based on SalEn‐type complexes have attracted considerable attention due to their potential applications in electrochemical devices. However, their charge transfer mechanisms, physical and electrochemical properties remain unclear, hindering their rational design and optimization. This study aims to establish the influence of monomer geometry on the polymer's properties by investigating the properties of novel nonplanar SalEn‐type complexes, poly[N,N'‐bis(salicylidene)propylene‐2‐(hydroxy)diaminonickel(II)], and its analog with 2,2,6,6‐tetramethylpiperidinyl‐N‐oxyl (TEMPO)‐substituted bridge (MTS). To elucidate the charge transfer mechanism, operando UV–Vis spectroelectrochemical analysis, electrochemical impedance spectroscopy, and electron paramagnetic resonance are employed. Introducing TEMPO into the bridge moiety enhanced the specific capacity of the poly(MTS) material to 95 mA h g−1, attributed to TEMPO's and conductive backbone's charge storage capabilities. Replacement of the ethylenediimino‐bridge with a 1,3‐propylenediimino‐ bridge induced significant changes in the complex geometry and material's morphology, electrochemical, and spectral properties. At nearly the same potential, polaron and bipolaron particles emerged, suggesting intriguing features at the overlap point of the electroactivity potentials ranges of polaron–bipolaron and TEMPO, such as a disruption in the connection between TEMPO and the conjugation chain or intramolecular charge transfer. These results offer valuable insights for optimizing strategies to create organic materials with tailored properties for use in catalysis and battery applications. [ABSTRACT FROM AUTHOR]

The present work reports the fabrication via FFF-3D printing of 3- and 8-YSZ electrolytes, which are considered the current state-of-the-art of electrolyte materials for high temperature fuel cells (i.e., SOFCs), using filaments with ceramic loadings in the 65 to 75 wt% range. Filaments, green bodies and sintered specimens have been produced and fully characterised using thermal, structural, morphological, rheological and electrochemical techniques. The 3D printed electrolytes exhibit chemical stability under the debinding and sintering conditions, without significant microstructural changes when compared to conventional press and sinter processing and very high relative densities, compatible with SOFC operation, i.e. > 95%. The conductivity of the 3D printed electrolytes was 0.05 and ≈ 0.1 S/cm at 1000 °C, for 3- and 8-YSZ respectively, which is very close to the values typically reported for conventionally processed zirconia electrolytes. These results confirm the potential application of FFF-3D printing technology towards the production of a new generation of electrochemical devices for energy production, such as SOFCs, with larger volumetric and surface energy densities and without their current geometrical limitations. [ABSTRACT FROM AUTHOR]

Replacing the slow protonation process of oxygen evolution reaction (OER) with the fast protonation of alcohol electro‐oxidation can decrease the driving potentials, thus improving overall efficiency of electrochemical devices. However, the formation of effective catalytic sites for alcohol oxidation remains challenging in accelerating protonation to inhibit metal leaching and improve catalyst stability. Herein, asymmetric Ni‐O‐Cr sites are constructed by alloying Cr into the NiO matrix to optimize coordination environments, showing significantly enhanced stability during alcohol electro‐oxidation. The asymmetric Ni‐O‐Cr can maintain constant valence states of Cr and Ni during alcohol oxidation, efficiently suppressing metal dissolution even at high oxidation potentials. In situ electrochemical characterizations combined with theoretical calculations indicate that asymmetric Ni‐O‐Cr can improve adsorption and activation of OH* and alcohol molecules compared to pure NiO, thus increasing anodic kinetics. The theoretical results also indicate that the smaller gap of Ni 3d‐O 2p in asymmetric Ni‐O‐Cr strengthens charge transfer, leading to fast protonation of catalytic sites with enhanced stability. This work gives insights into boosting anodic protonation using asymmetric sites‐enriched solid‐solution electrocatalysts. [ABSTRACT FROM AUTHOR]

The current study focuses on reviewing the actual progress of the use of ionic liquids and derivatives in several electrochemical application. Ionic liquids can be prepared at room temperature conditions and by including a solution that can be a salt in water, or a base or acid, and are composed of organic cations and many charge-delocalized organic or inorganic anions. The electrochemical properties, including the ionic and electronic conductivities of these innovative fluids and hybrids, are addressed in depth, together with their key influencing parameters including type, fraction, functionalization of the nanoparticles, and operating temperature, as well as the incorporation of surfactants or additives. Also, the present review assesses the recent applications of ionic liquids and corresponding hybrids with the addition of nanoparticles in diverse electrochemical equipment and processes, together with a critical evaluation of the related feasibility concerns in different applications. Those ranging from the metal-ion batteries, in which ionic liquids possess a prominent role as electrolytes and reference electrodes passing through the dye of sensitized solar cells and fuel cells, to finishing processes like the ones related with low-grade heat harvesting and supercapacitors. Moreover, the overview of the scientific articles on the theme resulted in the comparatively brief examination of the benefits closely linked with the use of ionic fluids and corresponding hybrids, such as improved ionic conductivity, thermal and electrochemical stabilities, and tunability, in comparison with the traditional solvents, electrolytes, and electrodes. Finally, this work analyzes the fundamental limitations of such novel fluids such as their corrosivity potential, elevated dynamic viscosity, and leakage risk, and highlights the essential prospects for the research and exploration of ionic liquids and derivatives in various electrochemical devices and procedures. [ABSTRACT FROM AUTHOR]

Doped-zirconia finds several applications as strucutral material and in different electrochemical devices; moreover, it is considered a model ceramic system. The consolidation of 3 mol% Y 2 O 3 stabilized ZrO 2 (3YSZ) by rapid sintering (flash processes) has yielded unusual properties like higher hardness and thinner electrochemical grain boundaries. To explore the effect of high heating rate and distinguish it from field-induced phenomena, we investigated and compared UHS (Ultrafast high-temperature sintering) with conventional heating with and without an electric field. The results show that: i) UHS allows ultra-rapid consolidation (<30 s) of YSZ nanopowders (≈20 nm) with a densification pathway different from conventional sintering in terms of microstructural evolution (UHS allows a grain size reduction by more than 60% at a fixed desnity level); ii) the electric field plays a minor role in sintering, microstructure evolution, and properties; iii) UHS does not affect the hardness and the grain boundary electrochemical properties of the sintered bodies. Whereas similarities can be pointed out between UHS and flash-related techniques in terms of accelerated densification and microstructure, the final properties are rather different with UHS YSZ being more similar to conventional sintering. [ABSTRACT FROM AUTHOR]

The electrochemical performance of a material is primarily determined by its composition, working mechanism, and electronic conductivity. We derive design recommendations of a simple route for preparing Ni–Co binary metal sulfides (NCS) on reduced graphene oxide (rGO) with outstanding electrochemical properties for all-solid-state supercapacitor fabrication. The combination of the two energy storage mechanisms and the synergistic effect between the redox centers are the main reasons for the excellent electrochemical performance of the rGO/NCS material compare to pristine rGO and NCS materials. Specifically, the rGO/NCS material exhibits a specific capacity 125 % higher than that of NCS material and becomes higher up to 224 % compared to the counterpart of the rGO at a current density of 2 A g−1, retention of up to 95.7% initial specific capacity after 10,000 cycles. In addition, in the power density ranging from 1.6 to 16 kW kg−1 the all-solid-state supercapacitor device based rGO/NCS material exhibited an energy density from 23.6 to 47.2 Wh kg−1. And thus, this work indicates that rGO/NCS is a potential material for manufacturing all-solid-state supercapacitors. [ABSTRACT FROM AUTHOR]

Electrochemical energy storage and conversion systems (EESCSs), including batteries, supercapacitors, fuel cells, and water electrolysis technologies, enabling the direct conversion between chemical and electrical energies. They are key to the flexible storage and utilization of renewable energy and play an important role in future energy technologies. The physical and chemical properties of electrode materials significantly influence the performance of EESCSs, necessitating the development of materials with both high cost‐effectiveness and superior electrochemical storage and catalytic capabilities. Layered double hydroxides (LDHs), due to their unique properties as high surface area, evenly distributed active sites, and tunable compositions, makes themselves and the derivatives have become focal points in the EESCSs. This review summarizes recent advances of LDH and their derivates for diverse EESCSs applications, aims to elucidate the modification strategies of LDH materials and provide valuable insights for exploring LDH‐derived materials in various electrochemical devices, offering interdisciplinary perspectives for the rational design of LDH‐based materials. [ABSTRACT FROM AUTHOR]

The extensive consumption of chicken has resulted in the emergence of a significant environmental issue in the form of chicken feather waste. As such, there is an urgent need for the development of green treatment and recycling methods for chicken feathers. Chicken feathers can serve as a type of heteroatomic doping carbon source, making them an excellent candidate for the electrode materials used in electrochemical energy devices. Furthermore, their unique structures and functional groups make them highly promising for use as adsorbents, electronics, and building materials. In this paper, we provide a summary and review of recent progress made in the use of chicken feathers for energy and environmental applications. Based on the theoretical knowledge and practical applications presented in this review, promising green recycling processes of chicken feathers can be developed. These processes can help to reduce environmental pollution and promote sustainable development. [ABSTRACT FROM AUTHOR]

The issues of scaling, pipeline corrosion, and the growth of sludge, bacteria, and algae within circulating cooling water systems have been consistently limiting the enhancement of production efficiency in enterprises. The trending new electrochemical water softening technology, with its environmentally friendly, high efficiency, and low energy consumption characteristics, offers a fresh approach to addressing the stable operation of industrial circulating water systems. This paper begins by detailing the mechanisms of active scale removal, sterilization, and algae control facilitated by electrochemical water softening technology. Subsequently, it compares and analyzes the crucial core components of electrochemical devices (including the selection and preparation of anode and cathode materials, as well as the power system). Furthermore, it introduces the main types and installation modes of electrochemical equipment available in the market. Additionally, it uncovers the key factors influencing the efficiency of electrochemical descaling and validates the impact of electrochemical water softening technology on industrial circulating water systems through illustrative examples. Lastly, the paper concludes by summarizing and forecasting the future development direction of this technology. [ABSTRACT FROM AUTHOR]

The outstanding thermal, chemical, and mechanical properties of ceramic membranes have attracted increasing attention, offering advantages over polymer and metal counterparts. Exploring the specialized applications of ceramic membranes through various preparation methods poses a daunting challenge for contemporary researchers. Traditional preparation methods are essentially unable to meet the requirements of complex membrane structures. For instance, in ceramic fuel cell applications, cells composed of ceramic membrane materials exhibit high resistance and low conductivity, which seriously hinders the progress of new high-performance ceramic fuel cells. Therefore, it is necessary to improve preparation methods to improve the electrochemical performance of devices composed of ceramic membrane materials. In recent years, breakthroughs in various new processing technologies have propelled the performance of ceramic membrane devices. This paper will focus on the following aspects. Firstly, traditional preparation methods and advanced preparation methods of ceramic membrane materials will be discussed. Secondly, high-performance ceramic membrane materials prepared by different advanced preparation methods are introduced, and the electrochemical properties of the devices composed of ceramic membrane materials are elaborated in combination with different testing and characterization methods. Finally, the prospects and future direction of the preparation of ceramic membrane materials by advanced preparation methods are summarized. [ABSTRACT FROM AUTHOR]

The synthesis of a pectin biopolymer and ionic salt (KI)-incorporated biopolymer composite electrolyte system is reported in this communication for electrochemical device fabrication. The solution cast technique is used to create composite electrolyte films of synthesized pectin biopolymer with KI salt at different concentrations. The conductivity achieved for the pectin biopolymer-based electrolyte films is up to the order of 8.1 × 10−6 S/cm, which is an increase of three orders over the conductivity (2.7 × 10−9 S/cm) of pure pectin. Electrical, structural, and optical studies of the biopolymer electrolyte films are carried out and described. The optical properties are represented by polarized optical microscopy images which show the amorphous nature of the electrolytes films. The electrochemical stability window (ESW) presents a potential window of 1.82 V, which makes the electrolyte film suitable for device fabrication. The maximum cationic transference number reveals the ionic nature of the biopolymer electrolyte films. [ABSTRACT FROM AUTHOR]

The search for novel functional ceramic materials with targeted properties is currently very important. Complex oxides with perovskite or perovskite-related structure are being considered for the production of electrochemical devices for the hydrogen energy ecosystem. Layered perovskites including based on BaLaInO 4 are promising materials for proton-conducting electrolyte of solid oxide fuel cells. The idea of this work is to create a triple conductivity material based on BaLaInO 4. In this work, the doping of the lanthanum sublattice with iron ions was carried out for the first time. The effect of doping on the structure, water uptake and electrical conductivity was investigated. It was shown that the introduction of iron ions into lanthanum sublattice changes the crystal lattice from orthorhombic to tetragonal structure. The water uptake is very small and it is 0.02 mol H 2 O per formula unit for BaLa 0.9 Fe 0.1 InO 4–δ composition. Studies of the electrical properties have shown that the nature of conductivity is mixed hole/oxygen ionic at dry air and hole/oxygen ionic/protonic and wet air. The Fe-doped-composition can be considered as triple conducting materials and it is prospective as the electrode materials comparable with protonic electrolyte Ba 1.1 La 0.9 InO 3.95. [ABSTRACT FROM AUTHOR]

The search for new promising ceramic materials for various applications is an important task. In particular, ceramic materials are required as a part of electrochemical energy devices such as solid oxide fuel cells. Layered perovskites are promising materials for proton-conducting electrolyte of solid oxide fuel cells. In this article, samarium doped composition BaLa 0.9 Sm 0.1 InO 4 was obtained for the first time. The effect of doping on the structure, water uptake and ionic transport (O2− and H+) was investigated. It was shown that the samarium doping leads to the increase in conductivity values of up to 2 orders of magnitude. At low temperatures the proton transport numbers are 87–93 %, which indicates dominance of proton transfer. [Display omitted] [ABSTRACT FROM AUTHOR]

Many proton-conducting oxides are refractory, making it difficult to fabricate dense electrolyte membranes for electrochemical devices. The use of a sintering additive is a common strategy, although it often has a negative effect on proton transport. We found that the addition of ZnO (2 and 4 mol%) successfully contributes to densification of SrHf 0.8 Sc 0.2 O 3-δ ceramics at 1450 °C without negative consequences for the ionic transport. The chemical stability of the materials, high levels of hydration and proton conductivity were confirmed. ZnO is partially (less than 0.3 mol%) incorporated into the crystal lattice of the perovskite and partially accumulates at grain boundaries gradually volatilizing during high-temperature treatments. As a result, ZnO sintering additive does not influence the bulk and specific grain-boundary conductivities, ionic transference numbers and hydration ability, maintaining the excellent electrolytic properties of SrHf 0.8 Sc 0.2 O 3-δ ceramics. [ABSTRACT FROM AUTHOR]

Hybrid electrochemical storage devices combining batteries and supercapacitors are essential for advancing energy storage technologies. Our study presents a simple one-pot synthesis method for nickel-cobalt selenide (NCSe) nanoparticles, optimizing selenium (Se) content to enhance microstructure, porosity, and electrochemical properties. NCSe nanoparticles with 1.8 mmol Se exhibited a remarkable specific capacity of 775 C g⁻1 at 1 A g⁻1 and 665 C g⁻1 with 85 % retention at 15 A g⁻1. An asymmetric supercapacitor using NCSe-1.8 mmol as the positive electrode and activated carbon as the negative electrode achieved 79 % retention after 2000 cycles at 15 A g⁻1. These findings underscore NCSe nanoparticles' potential as efficient electrode materials, advancing energy storage technologies. [ABSTRACT FROM AUTHOR]

Electrochemical devices based on proton conducting ceramic oxides have shown a high potential for conversion processes at intermediate temperatures. In these cells, perovskite ceramics like BaZr 0.7 Ce 0.2 Y 0.1 O 3-δ (BZCY), which are based on the solid solution of BaZrO 3 and BaCeO 3 doped with Y, have proven to be a good compromise between chemical stability and proton conductivity. However, the refractory nature of this material system requires high sintering temperatures to enable dense ceramic membrane layers. Recently, a novel processing route, which applies the cold sintering process (CSP) as a pre-densification step has been developed allowing to lower the sintering temperatures while maintaining excellent electrochemical properties. In this study, we further improved this method by implementing a BZCY/NiO support layer for BZCY. After final thermal treatment under reducing conditions, a dense BZCY membrane supported by a porous BZCY/Ni electrode support resulted. We show that using powder processing techniques, it is possible to sinter thick layered structures, consisting of an almost dense, phase pure perovskite BZCY layer and a porous BZCY/NiO layer. Furthermore , the NiO phase was successfully reduced to Ni by an additional thermal treatment at 900 °C in Ar/H 2. The focus of this study was to generally prove the feasibility of applying co-cold sintering for the processing of layered ceramic architectures, which can be used – after further optimization of the processing – as electrode supported fuel or electrolysis cells. [ABSTRACT FROM AUTHOR]

The double skeleton interpenetrating network fixed the quaternary ammonium salt, and various internal conduction modes cooperated to promote the transport of hydroxide ions. [Display omitted] The alkaline solid-state electrolytes have received widespread attention for their good safety and electrochemical stability. However, they still suffer from low conductivity and poor mechanical properties. Herein, we report the synthesis of double-network featured hydroxide-conductive membranes fabricated by polyvinyl alcohol (PVA) and chitosan (CS) as the double-skeletons. Then, we implanted quaternary ammonium salt guar hydroxypropyltrimonium chloride (GG) as the OH− conductor for high-performance electrochemical devices. By virtue of the unique stripe-like structure shared from the double skeleton with a high degree of compatibility and stronger hydrogen bond interactions, the polyvinyl alcohol/chitosan-guar hydroxypropyltrimonium chloride (PCG) solid-state electrolytes achieved optimal thermal stability (> 300 °C), mechanical property (∼ 34.15 MPa), dimensional stability (at any bending angle), and high ionic conductivity (13 mS cm−1) and ion mobility number (t ion ∼ 0.90) compared with chitosan-guar hydroxypropyltrimonium chloride (CG) and polyvinyl alcohol-guar hydroxypropyltrimonium chloride (PG) electrolyte membrane. As a proof-of-concept application, the "sandwich"-type zinc-air battery (ZAB) assembled using PCG membrane as the electrolyte realized a high open-circuit voltage (1.39 V) and an excellent power density (128 mW cm−2). Notably, in addition to its long-term cycle life (30 h, 2 mA cm−2) and stable discharge plateau (12 h, 5 mA cm−2), it could even enable a flexible ZAB (F-ZAB) to readily power light-emitting diodes (LED) at any bending angle. These merits afford the PCG membrane a promising electrolyte for improving the performance of solid-state batteries. [ABSTRACT FROM AUTHOR]

Lithium ion conducting membrane has been prepared based on cellulose acetate and LiCl using the solution casting method. Amorphous/crystalline nature of the prepared membranes are analyzed using X-ray diffraction. The surface of the prepared membrane is analyzed using SEM. Complexation of cellulose acetate and LiCl is confirmed using Fourier transform infrared spectroscopy. The ionic conductivity of the examined membranes is determined through AC impedance measurement. The membrane, comprising 1 g cellulose acetate with 0.8 weight% (wt%) of LiCl, exhibits the highest Li-ion conductivity of 7.1 × 10−3 S cm−1 among all prepared membranes. Thermal stability of the prepared membranes is analyzed using Differential scanning calorimetry and Thermogravimetric analysis. The electrochemical stability of the highest Li-ion conducting membrane has been analyzed using Linear sweep voltammetry (LSV), and the potential window was found to be 1.76 V. Using the highest Li-ion conducting membrane, the primary Li-ion conducting battery and coin cell is constructed. Primary Li-ion conducting battery shows an Open-circuit voltage (OCV) of 1.8 V and its performance has been studied using various loads. The stability of the coin cell is analyzed using the Galvanostatic charge-discharge. The performance of the highest Li-ion conducting membrane as an electrolyte in an electrochemical storage device is analyzed in the present work. [ABSTRACT FROM AUTHOR]

[Display omitted] • cMOF/LDH hetero-nano petals decorated with Metal-N sites shelled over WNO nanowire show superior bifunctional activity. • RuCoFe-NPs@WNO-NWs exhibits outstanding catalytic performance in OER (230 mV @ 10 mAcm−2) and HER (49 mV @ 10 mAcm−2) in alkaline medium. • RuCoFe-NPs@WNO-NWs needing only 1.49 V for an alkaline solution and 1.55 V for seawater. • Designed electrocatalyst holds promise for practical water-splitting applications. • Numerous exposed edges of WNO nanowires and active center sites within the formed cMOF/LDHs heterostructure contribute to the enhanced electrocatalytic activity. Addressing the challenges of enhancing water-splitting efficiency necessitates the exploration and rational design of high-performance and durable electrocatalysts with appealing nanoarchitectures. In this study, we present the design and fabrication of conjugated cMOF/LDH hetero-nano petals decorated with monodispersed Metal-N sites, which are uniformly shelled over tungsten oxynitride (WNO) nanowire arrays to form a unique core–shell architecture. For this rational engineering, WNO nanowire arrays were grown on carbon cloth. Then, a thin-layered Ru-Co-Fe layered double hydroxide (RuCoFe/LDH) was deposited around these wires, resulting in a highly porous three-dimensional array of hierarchical hetero RuCoFe-LDHs@WNO-NWs core–shell nanowires (RuCoFe-NSs@WNO-NWs). Subsequently, the linkers coordinated with the RuCoFe-LDH nanosheets and transformed them in-situ into the RuCoFe-cMOF nano petals (RuCoFe-NPs@WNO-NWs). Notably, the linker's amino groups functioned as hooks for precisely anchoring and stabilizing metal sites, forming the metal nitride (M-N) moieties. Interestingly, the designed bi-functional catalyst exhibited superior catalytic activities for both OER (230 mV @ 10 mAcm−2) and HER (49 mV @ 10 mAcm−2) in an alkaline medium. Additionally, an electrolyzer cell employing Ru-CoFe-NPs@WNO-NWs as a bi-functional electrocatalyst required 1.49V to reach a current density of 10 mA cm−2. These remarkable catalytic performances can be attributed to several key factors, including opulent exposed active sites, an efficient charge/mass transport pathway, an optimized electronic structure, and an interfacial synergy effect. Hence, this study provides a new perspective for the design of efficient bi-functional electrocatalysts for use in the energy related electrochemical devices. [ABSTRACT FROM AUTHOR]

The development of high-performance electrochemical energy devices requires efficient oxygen redox reaction (ORR) electrocatalysts. In particular, ceramic fuel cells suffer from insufficient oxygen reduction reaction (ORR) of the cathode material at low operating temperatures. Here we report a series of three-dimensions bulk LaFe 2 O 4 -WO 3 heterostructure composites synthesized by a citric acid complexing method for a solid oxide fuel cell's (SOFC) cathode material to work at lower operating temperature at 450-550 ° C. In various contents of LaFe 2 O 4 and WO 3 , the 7LaFe 2 O 4 –3WO 3 cathode exhibits very small area-specific-resistance (ASR) of 0.24 Ω cm2 and admirable peak power density of 625 mW-cm−2 when operating at 550 °C using Ni 0.8 0Co 0.15 Al 0.05 LiO 2-δ (NCAL) anode and Sm 0.20 Ce 0.80 O 2 (SDC) electrolyte, respectively. Different characterizations such as HR-TEM, XPS, Raman, spectroscopy and calculation density functional theory (DFT) methods has been used to identifying the main reason for the improved electrochemical performance through the interface between LaFe 2 O 4 and WO 3 heterostructure in comparison of individual LaFe 2 O 4 and WO 3 structures. We have found that the LaFe 2 O 4 -WO 3 heterostructure shows superficial oxygen ions release and electronic mobility which increase the overall active-sites for the enhanced ORR functionality. This aromatic approach can lead a step forward to develop desirable electrocatalysts by crosslinked interfacial properties using semiconductor-heterostructure materials for advanced energy devices. [Display omitted] [ABSTRACT FROM AUTHOR]

Rechargeable Zn–air batteries (ZABs) are considered highly competitive technologies for meeting the energy demands of the next generation, whether for energy storage or portable power. However, their practical application is hindered by critical challenges such as low voltage, CO2 poisoning at the cathode, low power density, and poor charging efficiency Herein, a rechargeable hybrid alkali/acid Zn–air battery (h‐RZAB) that effectively separates the discharge process in an acidic environment from the charging process in an alkaline environment, utilizing oxygen reduction reaction (ORR) and glycerol oxidation reaction (GOR) respectively is reported. Compared to previously reported ZABs, this proof‐of‐concept device demonstrates impressive performance, exhibiting a high power density of 562.7 mW cm−2 and a high operating voltage during discharging. Moreover, the battery requires a significantly reduced charging voltage due to the concurrent utilization of biomass‐derived glycerol, resulting in practical and cost‐effective advantages. The decoupled system offers great flexibility for intermittently generated renewable power sources and presents cost advantages over traditional ZABs. As a result, this technology holds significant promise in opening avenues for the future development of renewable energy‐compatible electrochemical devices. [ABSTRACT FROM AUTHOR]

The synthesis of ammonia starting from nitrogen and using electrochemical processes is considered an interesting strategy to produce ammonia in a sustainable way. However, it requires not only the development of efficient catalysts for nitrogen reduction but also the optimization of the operating conditions of the employed electrochemical devices. In this work, we optimize the kinetics and the thermodynamics of the electrocatalytic nitrogen reduction reaction in water by developing a pressurized H-cell that may operate at temperatures up to 80 °C. Ni foam with low Au loading (0.08 mg cm−2) has been adopted as a catalyst at the cathode. Ammonia has been produced during chronoamperometry experiments in a saturated N2 atmosphere and measured by the indophenol blue method. The effect of voltage, temperature, and pressure has been studied. The nitrogen reduction experiments have been repeated under saturated Ar. To remove contributions due to environmental contamination, we determined the net value as the difference between the produced ammonia in N2 and in Ar. The ammonia yield increases by increasing the temperature and the pressure. The best results have been obtained by using the combined effects of temperature and pressure. Operating at 5 bar of saturated N2 and 75 °C, a production rate of 6.73 μg h−1·cm−2 has been obtained, a value corresponding to a 5-fold enhancement, compared to that obtained under ambient conditions and room temperature. [ABSTRACT FROM AUTHOR]