Search

Research and development in Li-ion micro-batteries are focusing on improving their performance, energy density, and cost-effectiveness. These batteries continue to be an area of interest for applications where traditional battery technologies may not be as suitable due to size and weight constraints. In the present work, we report on the electrochemical properties, Li-ion dynamics, various contributions to charge storage, and the ability to glow a light-emitting diode (LED) using Li Nb O thin film electrodes deposited via the RF magnetron sputtering technique. X-ray diffraction and Raman spectra analysis identified mixed phases of the thin film of tetragonal Nb 2 O 5 and monoclinic LiNb 3 O 8 , both phases displaying the Nb5+ oxidation state, as verified by X-ray photoelectron spectroscopy. The cyclic voltammogram and dQ/dV plots demonstrated the two-electron transfers from each phase of the film and the kinetic property of the mixed phase is significantly contributed by both intercalation and pseudocapacitance behavior. The Li Nb O ultra-thin film of 19 nm delivers an initial discharge capacity of 9.9 µAh/cm2 at a current density of 20 µA/cm2 and attained capacity retention of 75.75 % after 300 cycles, indicating improved lithium storage. Additionally, impedance measurements are conducted to assess the reduction in charge transfer resistance before and after cycling, and to determine the Li-ion diffusion coefficient, which ranged from 10−17 to 10−20 cm²/s in the thin film. Thus, the Li Nb O thin films can be suitable as a negative electrode in all-solid thin film micro-batteries applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• Improved interconnectivity with CQD and electronic property with PEDOT of g-C 3 N 4. • Supercapacitor achieved a specific capacitance of 109.5 F/g at a current density of 0.2 A/g. • Dual EDLC and redox behavior stable at different scan rates and current densities. • Findings suggest improved energy storage capabilities (E=14.6 Wh kg−1 & P=1.4 kW kg−1). Energy storage technologies enable the efficient storage and release of energy, providing essential flexibility and stability to power grids worldwide. Supercapacitors are advanced energy storage systems capable of rapidly storing and releasing large amounts of electrical energy, offering long cycle life and high-power density. Herein, a carbon quantum dot (CQD) dispersed 2D graphitic carbon nitride (g-C 3 N 4) nanocomposite was deposited with poly(3,4-ethylene dioxythiophene) (PEDOT) by an electrodeposition technique. The structural, morphological, functional group, and elemental characteristics of the synthesized materials were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). An electrochemical study of electrode materials named g-C 3 N 4 , g-C 3 N 4 -CQD and g-C 3 N 4 -CQD/PEDOT (GCP) composites was performed. The GCP electrode-based symmetric supercapacitor device exhibited a specific capacitance (C s) of 109.5 F g−1 at a current density of 0.2 A g−1 in 1 M H 2 SO 4. Herein, the prime novelty is the incorporation of CQDs as spacers between g-C 3 N 4 layers, which substantially improved the surface area, providing potential benefits such as higher energy density and greater stability for supercapacitors. The supercapacitor device utilizing GCP demonstrated an energy density of 14.6 Wh kg−1 at a power density of 1.4 kW kg−1, operating at a current density of 0.2 A g−1. The improved electrochemical performance of the hybrid electrode materials is ascribed to the combined effect of the faradaic PEDOT and the non-faradaic CQDs incorporated into the g-C 3 N 4 matrix. [Display omitted] [ABSTRACT FROM AUTHOR]

Structural defects and heteroatoms play a key role in electrochemical reactions. However, there is still no common understanding of what has a greater impact on electrochemical processes: defects or the type of heteroatoms. To clarify these factors, defective carbon nanowalls treated by reactive etching in different atmospheres, such as argon and mixtures of argon with nitrogen, chlorine, hydrogen bromide, and sulfur fluoride were used. Properties of the obtained samples were analyzed with Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and cyclic voltammetry. The results of the study showed that the plasma modification of carbon nanowalls leads to the removal of the amorphous layer and subsequent implantation of heteroatoms, which ultimately leads to an increase in their areal capacitance 1.5-fold in a 1:2 argon - nitrogen mixture and 2-fold in a 1:4 argon-nitrogen mixture. [ABSTRACT FROM AUTHOR]

In the context of the global water shortage, the need for sustainable, energy-efficient desalination is paramount. Capacitive deionization (CDI), an emerging technology for water desalination, offers promise for addressing this issue. In this study, we introduce a new approach to reusing spent activated carbon (AC-spent) from water treatment plants through regeneration via acidic, neutral, and alkaline activating agents. We examine the effectiveness of regeneration on CDI performance. The X-ray photoelectron spectroscopy (XPS) analysis confirms the developed functional group during regeneration. The BET analysis revealed a significant increase in specific surface area (SSA) with potassium hydroxide treatment, achieving an impressive SSA of 1935 m2.g-1 compared to AC-Spent with 477 m2.g-1. Furthermore, treatment with potassium hydroxide yielded a significant specific capacitance of 88 F.g-1 at a scan rate of 2 mV.s-1 in 1 mol l-1 NaCl as electrolyte, surpassing AC-spent with 42 F.g-1. The desalination test indicated that using phosphoric acid and potassium hydroxide as treatments increased the salt adsorption capacity (SAC) to 14.4 mg.g-1 and 11.1 mg.g-1, respectively, with removal efficiencies of 40.6 % and 57.3 %, low energy consumption of 143.1 kJ.mol-1, and 18.4 kJ.mol-1 and a good charge efficiency of 40 %. We attributed this result to the developed porosity and the contribution of functional groups. [ABSTRACT FROM AUTHOR]

• The combinatory microdroplet setup enabled concurrent monitoring of electrochemical parameters and wettability. • Microscale corrosion measurements revealed differences in corrosion parameters not observed in macroscale experiments. • R p increased with surface roughness due to lower hydroxide and defect oxide levels. • Rough copper surfaces show lower R p than smooth samples after 30-day exposure. This study explored the effects of atmospherically formed surface films and surface roughness on Cu corrosion behavior. A comprehensive suite of surface analysis techniques, including X-ray photoelectron spectroscopy, scanning electron microscopy, contact angle measurements, and confocal microscopy, were utilized to characterize the physicochemical properties of the surface films formed over 30 days. Then, both macroscale and droplet electrochemical measurements, such as open circuit potential and linear sweep voltammetry, were performed to explore the films' effects on the aqueous and atmospheric corrosion behavior of Cu respectively. The results showed that the polarization resistance measured within the droplets was lower than that observed in macroscale experiments, attributable to the varying oxygen diffusion profiles. During atmospheric corrosion, the polarization resistance was dependent on the surface finish due to its impact on the film's composition. Surface characterization revealed the formation of hydroxide and defect oxides that varied between the different surface finishes, resulting in differences in polarization resistances over a 30-day period. However, the films did not affect the polarization resistance measured for samples that underwent aqueous electrochemical corrosion testing, possibly due to their solubility during the open circuit potential period prior to reaching a steady state. This study underscores the importance of surface films on atmospheric corrosion properties and brings skepticism to the need for cathodic cleaning of Cu during aqueous corrosion studies under aerated conditions. [ABSTRACT FROM AUTHOR]

• In the presence of N O 3 − ions, the electrodeposition of Z n 0 simultaneously involves three faradaic reduction processes. • The nucleation of Z n 0 occurs through a 3 D − d c process, with the simultaneous reduction of N O 3 − ions and the medium. • The Z n (O H) 2 species was formed on the surface of the electrodeposited Zn clusters. • Structures of the form Z n (O H) 2 / Z n 0 / F T O were obtained during the electrodeposition of Z n 0 in the presence of nitrates. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical techniques such as cyclic voltammetry and chronoamperometry were used to study the electrodeposition and Zn nucleation mechanisms onto Fluorine-doped tin oxide (FTO) substrate from a nitrate-based electrolytic bath. The cyclic voltammetry analysis displays a reduction process (Ic) that involves three simultaneous reduction reactions: reduction of zinc neutral species Z n C l 2 to Z n 0 , reduction of N O 3 − ions, and the evolution of H 2 from the reduction of the medium. In addition, due to the oxidizing nature of nitrates, the surface of the recently deposited Z n 0 was partially oxidized to Z n 2 + , which combines with O H − ions to form the Z n (O H) 2 species on the surface of the deposited Z n 0. Analysis of chronoamperograms showed that Z n 0 nucleation onto FTO occurs via diffusion controlled 3D nucleation in the presence of N O 3 − ions, with the simultaneous reduction of nitrate ions on the Z n 0 growth surface and the reduction of the medium occurs on the uncoated surface by the diffusion zones of Z n 0 growth. SEM and XPS analysis of the deposits obtained from the chronoamperometric study evidenced the formation of the Z n (O H) 2 surface species. Consequently, structures of the form Z n (O H) 2 / Z n 0 / F T O were obtained during the electrodeposition of Z n 0 in the presence of nitrates. [Display omitted] [ABSTRACT FROM AUTHOR]

• A ternary ZGNC CE was synthesized via a simple hydrothermal method for DSSCs. • DSSCs with a ZGNC CE showed improved surface area and achieved a PCE of 6.9 ± 0.6 %. • ZGNC CE is a viable Pt-free alternative for counter electrodes in DSSCs. The counter electrode (CE) plays a pivotal role in enhancing the performance of dye-sensitized solar cells (DSSCs). Recently, platinum (Pt) has served as the preferred catalyst for CEs; however, due to its elevated cost, constrained accessibility, and vulnerability to deterioration, a compelling need exists to investigate alternative materials with superior performance for CEs. This research endeavours to tackle the inherent low conductivity challenge associated with ZnCo 2 O 4 and systematically explores avenues for augmenting its electrical characteristics. To accomplish this, we employed a facile hydrothermal technique to synthesise four different CE materials: pure ZnCo 2 O 4 (Z), ZnCo 2 O 4 combined with reduced graphene oxide (rGO) (ZG), ZnCo 2 O 4 /rGO combined with g-C 3 N 4 (ZGC), and ZnCo 2 O 4 /rGO combined with N-doped porous g-C 3 N 4 (ZGNC). Subsequently, we evaluated their suitability as CE materials for DSSC application. To ascertain the purity of the materials, we conducted X-ray diffraction (XRD) and FT-IR analyses, which revealed the absence of impurities. Morphological and elemental assessments were carried out using Field Emission Scanning Electron Microscopy (FE-SEM), Electron Probe Micro-Analyzer (EPMA), and Transmission Electron Microscopy (TEM). These analyses confirmed the desired morphology and elemental distribution in all synthesised samples and CEs. Chemical composition and purity were determined through X-ray Photoelectron Spectroscopy (XPS) analysis. Additionally, we conducted BET analysis, which demonstrated that the ZGNC sample possessed a greater specific surface area (94.3 m² g⁻¹) and pore volume (0.6 cm³ g⁻¹) than the other samples. To evaluate the electrochemical performance of the coated CEs, cyclic voltammetry (CV) analysis was conducted using an iodine-based electrolyte in a three-electrode configuration. The analysis revealed that the ZGNC CE exhibited significantly enhanced catalytic properties compared to the Z, ZG, and ZGC CEs. Subsequently, the fabricated CEs were integrated into DSSC devices, and the ZGNC CE attained a photovoltaic PCE of 6.9 ± 0.6 %, outperforming the Z (3.6 ± 0.4 %), ZG (5.3 ± 0.6 %) and ZGC (6.3 ± 0.2 %) CEs. [ABSTRACT FROM AUTHOR]

• Development of p-n hetero junction ZCO@Ni-MOF-based electrode via hydrothermal process. • The performed electrochemical studies are in clear agreement to each other and supported with Ex-situ XRD and operando EIS analysis. • Asymmetric supercapacitors exhibiting the performance up to an energy density of 13.6 Wh kg−1at a power density of 255 W kg−1. • Efficient oxygen evolution reaction performance producing over potential of 340 mV at current density of 50 mA cm−2. The stable structure and material combination design significantly improve the performance of electrochemical energy storage and water splitting. In the present study, we developed a ZCO@Ni-MOF core-shell structure over a nickel foam electrode, which is synthesized through a two-step hydrothermal treatment. The developed material is comprehensively analyzed to confirm structural, chemical, electronic, surface, and morphological characteristics using X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscope (SEM), and transmission electron microscope (TEM). Electrochemical investigations using a three-electrode system revealed that ZCO@Ni-MOF demonstrated an impressive specific capacitance of 1800 F g−1 at a current density of 2 A g−1 in a 1 M KOH electrolyte. The electrochemical findings are consistent across various electrochemical techniques. Furthermore, in-depth studies regarding p-n junction formation, interlayer spacing, and reaction kinetics studies are briefly analyzed with Mott-Schottky, Ex-situ XRD, and operando impedance studies. Moreover, an asymmetric supercapacitor (ASC) is assembled with ZCO@Ni-MOF as the positive electrode and activated carbon as the negative electrode in a Swagelok cell. This configuration demonstrated an energy density of 13.6 Wh kg−1 at a power density of 225 W kg−1. The ASC exhibited performance by retaining 91 % of its initial capacity even after 1500 cycles. For practical demonstration, two ASCs are fabricated and assembled in series to light up an LED, and the light-up duration is analyzed. For the oxygen evolution reaction (OER) study, the ZCO@Ni-MOF-based electrode exhibited activity with a lower overpotential of 340 mV (50 mA cm−2) in an alkaline environment and was responsible for stability for about 10 h. This combination reiterates the promising material aspects in energy storage and conversion devices, instilling hope for its potential applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• Coupled (CuO-Co 3 O 4) and mixed (CuCo 2 O 4) metal oxides were synthesized and characterized. • Simple hydrothermal and calcination approach was employed for the synthesis. • Electrocatalytic oxidation of hydrazine was realized at these oxides. • CuO-Co 3 O 4 exhibits higher electrocatalytic activity compared to CuCo 2 O 4. • Synergistic interaction and more exposed surface active sites are revealed in CuO-Co 3 O 4. This work reports the synthesis of copper- and cobalt-based coupled and mixed metal oxides (CuO-Co 3 O 4 and CuCo 2 O 4 , respectively) utilizing a simple hydrothermal and calcination approach. CuO-Co 3 O 4 , CuCo 2 O 4 , and the control samples were characterized by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray, and X-ray photoelectron spectroscopy. TEM and FE-SEM analyses of CuO-Co 3 O 4 reveal the presence of two distinct morphologies: rod- and sphere-shaped particles (CuO and Co 3 O 4 , respectively). Further, CuO-Co 3 O 4 was efficiently utilized as an electrocatalyst for the selective oxidation of hydrazine (Hyz). CuO-Co 3 O 4 shows a high redox response compared to CuO, Co 3 O 4 , CuCo 2 O 4 , and the physical mixture of CuO and Co 3 O 4 (CuO/Co 3 O 4). This enhanced performance is attributed to the synergistic interaction between the metal ions caused by their close proximity and the increased exposure of surface active sites. CuO-Co 3 O 4 shows a broad linear range (1–3500 µM), a low detection limit (0.29 µM), and high sensitivity (0.5756 µA µM-1 cm-2) for the Hyz determination. Kinetic parameters, for instance the diffusion coefficient and catalytic rate constant for Hyz oxidation were obtained using chronoamperometry. Additionally, CuO-Co 3 O 4 was effectively utilized to analyze Hyz in real samples with acceptable recovery rates. [Display omitted] [ABSTRACT FROM AUTHOR]

• Zinc and aluminium doped SnSb i.e. Sn 0.95 SbZn 0.05 , Sn 0.9 SbZn 0.1 , Sn 0.95 SbAl 0.05, and Sn 0.9 SbAl 0.1 were prepared through chemical co-precipitation method. The crystal structure and phase formation were confirmed by powder X-ray diffraction measurement. • Techniques such as cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy were scrutinised by using the three-electrode. system to study the electrochemical properties of SnSb 0.95 Zn 0.05 , SnSb 0.9 Zn 0.1 , SnSb 0.95 Al 0.05 , and SnSb 0.9 Al 0.1. In this case, SnSb 0.95 Zn 0.05 achieved a higher specific capacitance value of 588 F/g than other doped materials. • Based on the Swagelok assembly, an asymmetric supercapacitor device was fabricated in which SnSb 0.95 Zn 0.05 acts as a positive electrode and activated carbon acts as a negative electrode. The device has achieved high energy and power density of 8.57 wh/kg and 4266W/Kg and has displayed remarkable capacitance retention of 100.8 % after 5000 cycles. Supercapacitors or electrochemical capacitors are known for their supporting pulse power because of their high-power density compared to the battery. In this work, Al and Zn doped SnSb, i.e., Sn 0.95 SbZn 0.05 , Sn 0.9 SbZn 0.1 , Sn 0.95 SbAl 0.05, and Sn 0.9 SbAl 0.1 have been synthesized through chemical co-precipitation method. The powder X-ray diffraction, Raman spectroscopy, and UV–visible spectroscopy are intensely scrutinised to infer the phase formation, vibrational, and optical properties of the synthesized materials. Furthermore, the SEM, TEM, and X-ray photoelectron spectroscopy are used to study the material's morphology, chemical, and oxidation state; the Zn-doped SnSb alone focused because of their better electrochemical performance than the Al-doped SnSb. Using a three-electrode setup, the electrochemical performance of the following Sn 0.95 SbZn 0.05 , Sn 0.9 SbZn 0.1 , Sn 0.95 SbAl 0.05, and Sn 0.9 SbAl 0.1 are evaluated in that Sn 0.95 SbZn 0.05 has recorded higher specific capacitance of 588 F/g at 1A/g than the other. Then, the electrochemical analysis is further proceeded with the fabrication of an asymmetric device based on Swagelok assembly in which activated carbon acts as the negative electrode and Sn 0.95 SbZn 0.05 as the positive electrode and has recorded the maximum power and energy density value of 4266 W/Kg and energy density of 8.57 Wh/Kg. It also has shown outstanding cyclic stability for 5000 charge-discharge cycles at 10 A/g. Graphical representation of the synthesis of Sn 0.95 SbZn 0.5 and their potential application for fabricating the Swagelok assembly-based asymmetric supercapacitors (ASSC) device. [Display omitted] [ABSTRACT FROM AUTHOR]

• Three novel linear PTO-based COPs was fabricated via Suzuki coupling reaction. • The P(PTODB)-2 shows a high initial specific capacity of 210 mA h g-1 at 0.1 A g-1. • Superior rate properties (150 mA h g-1 at 5 A g-1) could be achieved. • The ex-situ FT-IR and XPS tests have proved lithium storage mechanism with C=O groups. Conjugated organic polymers (COPs) have been emerged as a class of cathode materials for lithium-ion batteries (LIBs) because of the rigid structural units and tunable properties. Nonetheless, their applications are still limited due to the poor conductivity and low cycling life. Herein, we design a series of pyrene-4,5,9,10-tetraone-based COPs (P(PTODB)-1, P(PTODB)-2, P(PTODB)-3), containing different number of benzene rings as linking units. Consequently, prolonging the linker lengths could effectively improve structural stability and extend π-conjugation, leading to the enhanced charge-storage capability. When tested as cathode materials for LIBs, the P(PTODB)-2 electrode delivers a better electrochemical performance with high capacity of 203 mA h g-1 after 100 cycles at 0.1 A g-1 (coulombic efficiency almost 100%) and excellent rate performance (150 mA h g-1 at 5 A g-1). In addition, the Li+ storage mechanism was carried out by ex situ Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis. Eventually, our study brings forward the appropriately extended linker lengths to fabricate COP cathodes with high electrochemical properties. [Display omitted] [ABSTRACT FROM AUTHOR]

Capacitive Deionization (CDI) is an electrochemical desalination technique based on the electrical double layer, which accumulate salts from the water stream; however, achieving higher salt adsorption for low-concentration salt is hindered due to several obstacles, such as low adsorption capacity and slow kinetics on the electrode surface. In this study, we reported a novel electrode fabrication method designed to enhance the hydrophilicity of the electrode material and activate hierarchical porosity, making a more accessible adsorption surface area. This modification enables more than 210 % improvement in salt adsorption capacity, achieving 17.5 mg g-1 in a single pass process with good stability in an 850 mg/L NaCl solution at 1.2 V, surpassing most reported carbon-based electrodes under similar operating conditions. Electrode formulation consists of Nitrogen (N) and Phosphorus (P) doped hierarchical carbon nanotubes (CNTs) network blended with additional NaCl as a green and removable template to reach higher levels of porosity. The electrochemical sorption behavior of the sample was characterized over a voltage range of –0.5 to 0.7 V. Furthermore, the electrode materials were characterized utilizing various characterization methods, including Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Raman Spectroscopy, Fourier Transformed Infrared (FTIR), X-ray Photoelectron Spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) to explore the correlation between microstructure, morphology, and properties. Our finding reveals that not only N and P can affect adsorption, but also the novel cathode preparation method, which employs a removable NaCl templated hierarchical porous electrode, has a profound effect on the electrochemical and CDI results. This finding will open a new perspective in designing electrodes for all electrochemical systems. [ABSTRACT FROM AUTHOR]

The recovery of ruthenium from low-concentration solutions poses a significant challenge due to its scarcity and rising economic value, and nano-impact electrochemistry has emerged as a promising method for efficient recovery of critical metals from solution through deposition during impacts of non-metallic nanoparticles. In this study, we investigate the redox chemistry of ruthenium on carbon black via the impact technique and demonstrate the ability to recover ruthenium from solution. The reduction (electrodeposition) and oxidation of Ru3+ ions in solution onto carbon black nanoparticles can be observed during nano-impacts with the respective onset potentials of these redox processes agreeing with those obtained from solution voltammetry. Upscaled experiments focusing on the electroreduction process, led to the formation of RuOx deposits, confirmed through scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) analysis, X-ray photoelectron spectroscopy (XPS) analysis, and thermogravimetric analysis (TGA). Under partially-optimised conditions, >90 % recovery of Ru(III) from a 1 mM solution was achieved in ca. 8 h. [Display omitted] [ABSTRACT FROM AUTHOR]

Rechargeable aluminum-ion batteries (RABs) are promising for energy storage due to their high theoretical energy density, but face challenges in cathode materials that match aluminum's capacity and stability. We propose copper (Cu) as an inexpensive and easily synthesized cathode material for RABs, using KetjenBlack (KB) as a carbon framework to enhance cycling stability by reducing structural damage. Key findings include: (1) Specific capacities of 793.5 mAhg-1 (charge) and 414.5 mAhg-1 (discharge) at 2 Ag-1 current density; (2) Good rate performance with a capacity maintained around 200 mAhg-1 at 12 Ag-1; (3) After 300 cycles at 2 Ag-1, discharge capacity stabilized at 225.1 mAhg-1. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were used to analyze electrode changes and understand the Cu/KB||Al battery's energy storage mechanism. This study introduces a novel electrode material and proposes a carbon framework for enhancing RAB performance. [ABSTRACT FROM AUTHOR]

• Mesoionic carbenes (MICs) are used for the first time to modify surfaces. In comparison to NHCs, MICs offer more versatility to immobilize functional groups since they are covalently grafted by click chemistry. • We demonstrate the approach by presenting results with 5 molecules bearing different functional groups, including 3 electroactive ones (no study in this domain features that many substrates). • A wide range of spectroscopic techniques are used: X-ray photoelectron Spectroscopy, infrared Spectroscopy, and even Tip-Enhanced Raman Spectroscopy which provides a local analysis of the surface (once again, no corresponding study has included such a variety of analyses for surface characterization). • The monitoring of MIC grafting as a function of electrode immersion time could be simply performed by cyclic voltammetry. • We demonstrate that reversible exchange reactions are possible between MICs and dodecanethiol on gold surfaces, opening the route for mixed assemblies. Significant progress has been made over the last decades in surface functionalization of coinage metals using thiols and more recently N-heterocyclic carbenes. As shown in this work, mesoionic carbenes (MICs) provide straightforward access to a novel class of surface ligands including electroactive ones and thus materials. Importantly, MICs are easily accessed from triazolium salts (TS) onto which functional groups may be attached with little synthetic effort. Here, we present a library of TS that were further converted, in situ , into MICs and grafted onto gold surfaces. The modified surfaces were thoroughly characterized by advanced spectroscopic methods such as XPS, infrared and Tip-Enhanced Raman Spectroscopy. Through cyclic voltammetry at 100 Vs-1, we could evaluate the surfacic concentration of the grafted molecules for electroactive MICs. We also prepared mixed MIC/thiol self-assembled monolayers, which opens the route to multifunctional surfaces. Triazolium salts bearing redox active or Raman responsive pendant functional arms are easily synthesized through Click Chemistry followed by N3-quaternization. These salts are applied as mesoionic carbene (MIC) precursors for the formation of active self-assembled monolayers (SAMs) on gold surfaces. Ligand grafting on gold was confirmed by cyclic voltammetry (CV), XPS, Raman and TERS spectroscopies. [Display omitted] [ABSTRACT FROM AUTHOR]

• Solvothermal synthesis of MOF-derived Co 3 O 4. • C3 sample show porous morphology. In this work, three-dimensional (3D) nanoporous MOF-derived Co 3 O 4 was successfully prepared by a facile, easy, and rapid solvothermal method on a stainless steel substrate using 1, 4-BDC organic linker and a precursor. Additionally, the effects of the Co-precursor and organic linker on the structure, composition, and morphology of the prepared MOF-derived Co 3 O 4 samples were investigated through an XRD study, which indicated that the MOF-derived Co 3 O 4 thin films exhibited crystalline nature upon deposition on the stainless steel substrate. FE-SEM revealed a porous nanosheet-like morphology. EDAX analysis confirmed the formation of the MOF-derived Co 3 O 4 structure, indicating the presence of cobalt, oxygen, and carbon elements. The oxidation states of the prepared MOF-derived Co 3 O 4 thin films were determined by X-ray photoelectron spectroscopy. Furthermore, the electrochemical performance of the MOF-derived Co 3 O 4 samples was evaluated in a three-electrode system using 1 M KOH electrolyte. Consequently, optimized MOF-derived Co 3 O 4 exhibited excellent electrochemical performance attributed to these advantages. The C3 sample demonstrated an outstanding specific capacitance of 1210 F/g at a current density of 0.5 mA/cm², along with remarkable cyclic stability retention of 94.30 % after 4000 charging/discharging cycles. Additionally, the MOF-derived Co 3 O 4 (C3) electrode showed an excellent energy density of 35.70 Wh/kg and a power density of 4.5 kW/kg. As a result, the unique hierarchical porous structure of MOF-derived Co 3 O 4 also offers effective pathways and excellent electrochemical performance, making it a promising candidate for advanced electrode materials in high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

• Metallic Ni catalyzes the HHOR below the reversible hydrogen electrode potential. • Ni catalyzes 4-electron HHOR, suggesting complete hydrazine oxidation. • OH− and OH ads are the reactive species for the HHOR on Ni. • Strongly adsorbed NH x species formed during the HHOR partially block Ni surface. Metallic Ni surface was examined as a catalyst for the hydrazine hydrate oxidation reaction (HHOR) by cyclic voltammetry, chronoamperometry, and online differential electrochemical mass-spectrometry (DEMS). It was found that N 2 is the sole gaseous product formed during the HHOR on Ni and 4 electrons are transferred in the process, which corresponds to a complete oxidation of the hydrazine molecule. The mechanism of the HHOR on the Ni surface involves OH− and adsorbed OH ads intermediate, the latter improving the rate of the HHOR. Ni catalysts were found to be poisoned during the HHOR, the extent of poisoning depending on the number of surface sites, hydrazine concentration, and the α-Ni(OH) 2 coverage. Ex situ X-ray photoelectron spectroscopy (XPS) measurements were performed to characterize the species poisoning Ni surface. [ABSTRACT FROM AUTHOR]

Extrusion-based 3D printing technologies, especially fused filament fabrication (FFF) using conductive filaments, have significantly advanced in electroanalytical applications by enabling the fabrication of electrochemical sensors. Nonetheless, 3D-printed electrodes produced from commercially available conductive filaments (e.g. , polylactic acid containing carbon black - CB/PLA) often contain a low amount of conductive material (∼20 % wt. carbon black), requiring surface activation protocols to enhance their electrochemical performance. In this study, we investigated the combination of blue-laser (BL) irradiation and (electro)chemical treatment (EC) to improve the performance of 3D-printed electrodes. For this purpose, 3D-printed CB/PLA electrodes were subject to blue laser activation (laser power = 280 mW and scan rate = 30 mm s-1) followed by an electrochemical procedure in 0.5 mol L-1 NaOH solution (application of +1.4 V and – 1.0 V both for 200 s). After the combined treatment, a considerable improvement in the voltammetric profile response (I pa/ I pc = 1.00 and ΔEp = 136 mV) was achieved using 1 mmol L-1 [Fe(CN) 6 ]3-/4- (equimolar concentration) as the redox probe when compared to polished electrodes (I pa/ I pc = 0.85 and ΔEp = 690 mV). Scanning electron microscopy, infrared spectroscopy data and X-ray photoelectron spectroscopy showed that the combined treatment promotes the remotion of insulating PLA material, exposing more conductive sites and functional groups. Moreover, electrochemical impedance spectroscopy results showed low resistance to charge transfer and capacitance double-layer measurements revealed an increase in the electroactive area after surface activation. As proof of concept, emerging contaminants such as hydroxychloroquine (HCQ) and paracetamol (PRT) were determined in tap water and pharmaceutical samples using treated 3D-printed CB/PLA electrodes and square-wave voltammetry. Linear ranges of 0.20 - 12.30 µmol L-1 and 1.0–30.0 µmol L-1 with limit of detection values of 0.01 and 0.2 µmol L-1 were obtained for HCQ and PRT, respectively. Appropriate recovery values (90 - 111 %) for the analysis of spiked samples were achieved. [ABSTRACT FROM AUTHOR]

A multi-principal element alloy consisting of equi-atomic concentrations of Cr, Ni, Ti, and V, was produced by arc melting. The CrNiTiV alloy was characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and scanning transmission electron spectroscopy (STEM), revealing a complex microstructure containing five phases. The corrosion performance of the alloy was evaluated with cyclic potentiodynamic polarization tests, indicating a low corrosion current density, a high breakdown potential and high repassivation potential. X-ray photoelectron spectroscopy and STEM were carried out after constant immersion in 0.6 M NaCl solution, revealing the passive (surface) film for each of the five phases. The Cr and V dominant phase consisted of an oxidized Cr/V-rich surface film, while the remaining four Ti-containing phases were predominantly TiO 2 -rich surface films. Ni enrichment and Ti deficiency were observed at the metal/oxide interface in certain Ti-containing phases. [ABSTRACT FROM AUTHOR]

• Cost effective synthesis of nano coral structured dual phase 1T/2H MoS 2 electrode material prepared via facile one step hydrothermal approach. • The electrochemical tests were examined through both three and two cell configurations. • The as prepared A-36 MoS 2 working electrode exhibits a high specific capacitance of 1550.86 F/g at current density of 1 A/g manifests an excellent rate capability (96.5% capacity retention after 1000 cycles). • The two-cell asymmetric configuration demonstrated 97% of capacitive retention even after 5000 cycles at 10A/g. • This device made the red LED lit up for 3 minutes, which conclude that this material can be used in miniature level energy storage devices. This article optimizes the synthesis parameters of nano coral structured (NC-S) molybdenum disulfide (MoS 2) using hydrothermal method and enhances its physiochemical properties for high-performance supercapacitors (SC). This nano coral architecture of transition metal dichalcogenides has garnered significant attention for efficient pseudocapacitive charge storage in SC. Herein, this work demonstrates the fabrication of dual phase MoS 2 by tailoring the reaction time of the NC-S. Furthermore, this effect has been explained with the help of several analytical techniques. The synthesized 1T/2H MoS 2 NC-S phase was affirmed by powder X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy studies. The field emission scanning electron microscope and transmission electron microscope images unveiled nano corals like morphology with numerous active sites. Impressively, the as prepared 24, 36 and 48 h MoS 2 NC-S entrenched as working electrode endows the achievement with a greater specific capacitance of about 761.82, 1550.86 and 1036.28 F/g at 1 A/g of current density manifests an outstanding rate capability of 94.5, 96.5 and 95.3% capacitive retention even after 1000 cycles. Among them, the 36 h (A-36) synthesized NC-S MoS 2 possess high specific energy (43.61 Wh/kg) and power (225.50 W/kg) for this application. Additionally, it demonstrates a commendable capacitive retention of 97% for the two-cell asymmetric setup, even after 5000 cycles at 10 A/g of current density. This inventive configuration of a two-cell device is employed using a Swagelok setup, where the 1T/2H phase MoS 2 NC-S//AC exhibit outstanding storage stability and sustained up to 180 sec. The promising results validate that this material can significantly enhance performance in energy storage applications. [Display omitted] Graphical scheme of the prepared 1T/2H MoS 2 electrode for supercapacitor application [ABSTRACT FROM AUTHOR]

• Electrode fabrication process affects surface morphology, crystals and compositions. • The fabrication process includes calcination temperature, support and quenching. • Pd 0.09 Sn 0.91 /SS@100 °C electrode is the best in electrochemical nitrate reduction. • Low temperature electrode showed better NO 3 − removal efficiency and N 2 selectivity. The effects of fabrication process, namely, calcination temperature, electrode support, and quenching, on electrochemical nitrate reduction were investigated, exemplified by Pd 0. 09 Sn 0. 91 electrode. The electrode was characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, and cyclic voltammetry. Results showed that electrode surface morphology, crystalline formation, and chemical composition, which were influenced by the electrode fabrication process, controlled nitrogen selectivity and nitrate reduction reactivity. The Pd 0. 09 Sn 0. 91 /SS electrodes were calcined at different temperatures (from 100 to 700 °C) for 3 h in air and the results showed that high calcination temperature rendered electrode oxidized, and decreased nitrogen selectivity and nitrate reduction capability. Electrode supports affected nitrate reduction following the order of Ni ≈ SS > G > Ti. Quenching electrode in ice water decreased nitrate reduction capability. Porous surface with small oxygen content, less degree of metal oxidation (i.e., higher fraction of Pd0 and Sn0), and Sn crystals favored nitrogen selectivity and nitrate removal. [Display omitted] [ABSTRACT FROM AUTHOR]

• The effect of molybdate and vanadate as corrosion inhibitors for clad AA2024-T3 was investigated. • The inhibition degree by vanadate is linear in the concentration range from 0.5 mM to 250 mM. • The inhibition degree of molybdate is similar to vanadate for c ≤ 50 mM. • For c > 50, the inhibition effect of molybdate strongly increases shifting E br for 400 mV more positive. • The morphology and thickness of inhibitor layers on clad AA2024-T3 strongly differ for molybdate and vanadate. Molybdate and vanadate ions were used as corrosion inhibitors for the clad aluminium alloy 2024-T3 in chloride solution to investigate the differences in their inhibitory effect. Electrochemical measurements in 0.1 M NaCl investigated the influence of inhibitor concentration from 0.5 mM to 250 mM, solution pH from 5 to 9 and immersion time at open circuit potential of up to 12 h. Both compounds act predominantly as anodic inhibitors; however, the effect of molybdate increases significantly at concentrations above 50 mM and leads to a broad passive range. Surface analysis of the samples exposed to inhibitor performed by X-ray photoelectron spectroscopy showed that the inhibitor layers consist of oxides of multiple valences. Scanning electron microscopy with chemical analysis was also used to characterise the inhibitor layers. Equilibrium diagrams of the aqueous species in the selected concentration range were generated to better understand the inhibition mechanism and to correlate the electrochemical data and data on surface properties. [Display omitted] [ABSTRACT FROM AUTHOR]

• The low-cobalt single-crystal F-LRM with the size above 800 nm was prepared by a co-precipitation and solid reaction sintering method. • The F-LRM cathode displays a high specific capacity of 309 mAh g −1 at 0.1 C. • The F-LRM shows the capacity retention is 90.6 % after 300 cycles under 1 C. • F doping forms strong TM-F bonds, improving the structural stability. • Appropriate OVs can inhibit phase transformations and improve the reversible capacity. Li-rich manganese-based layered oxides (LRM) can be regarded as the next-generation cathode materials for high-energy-density Li-ion batteries. The single crystalline LRMs make it have the potential to further application due to the higher compaction density and the absence of intergranular cracks. However, it can't meet the requirements for high energy density cathode materials because of its poor discharge capacity and unsatisfactory stability. In this study, we demonstrate the F doped single-crystal LRM (F-LRM) with the size is >800 nm giving an initial discharge capacity of 309 mAh g −1 at current density of 0.1 C (25 mA g −1) and the capacity retention is reaching up to 97.4 % after 100 cycles. Additionally, its rate capability is up to 206 mAh g −1 under 250 mA g −1 with 90.6 % and 80.6 % retention after 300 and 500 cycles, respectively. X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Raman indicated that the F-doped LRM forms strong TM-F bonds and creates a suitable oxygen vacancies (OVs) concentration. Furthermore, operando Differential Electrochemical Mass Spectrometer (DEMS) and High-resolution Transmission Electron Microscopy (HRTEM) analysis revealed that O 2 for F-LRM does not appear during the (de)lithiation with the layered structure maintained after cycling. The design of high-performance, low-cobalt single crystal materials offers a novel approach for the future development of lithium-rich cathodes. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, Ni was employed to enhance the mechanical properties of nanotwinned copper (NT-Cu) foils due to its excellent oxidation resistance and compatibility with Cu. The tensile strength of the NT-Cu foils was enhanced 12.6 % (752.8 to 847.3 MPa) by Ni co-electrodeposition. During the electroplating, it was found that Ni ions inhibited the Cu growth, causing the reduction potential (overpotential) to shift in the negative direction. It resulted in a reduced deposition rate and decreased the twin spacing of the foils. Additionally, Ni ions acted as impurities for the grain refinement. Time of flight secondary ion mass spectrometry (TOF-SIMS) results indicated that Ni atoms were deposited on the top and bottom of the foils due to the limiting current density of Ni. The NT-Cu-Ni exhibited low roughness and performed superior resistance to oxidation compared to the NT-Cu. X-ray photoelectron spectroscopy (XPS) was also utilized to characterize the oxidation of the Cu (Ni) alloys. These mechanisms contributed to high strength, low resistivity, and excellent oxidation resistance of the NT-Cu-Ni foils for future battery materials. [ABSTRACT FROM AUTHOR]

Lithium-ion battery (LIB) is now widely used in the world. However, its unsatisfactory fast-charging performance is limiting its applications. The fast-charging capability of LIB is highly affected by the surface composition of graphite electrode, which can be modified through electrolyte design. Herein we demonstrate that the combination of lithium bis(fluorosulfonyl) imide (LiFSI) salt with methyl acetate (MA) additive in carbonate electrolyte enables fast-charging Li-ion battery. Results from X-ray photoelectron spectroscopy and transmission electron microscopy indicate that the LiFSI-based electrolyte with MA forms a stable and less-resistive solid electrolyte interphase on graphite anode compared to electrolyte with LiPF 6 , facilitating the transport of Li-ion and achieving a superior fast-charging performance with a capacity of 230 mAh g −1 at 2 C. An electrolyte swapping experiment also indicates that the LiFSI salt forms a more stable SEI on graphite than LiPF 6. This work provides a conducive electrolyte design for fast charging Li-ion battery with graphite anode. [ABSTRACT FROM AUTHOR]

• The corrosion of multiphase al-zr-fe alloys containing intermetallics was studied in aqueous solutions of 3.5 % NaCl, H 3 BO 3 and 3.5 % nacl + H 3 BO 3. • 8-week immersion corrosion tests in 3.5 % nacl at 40 °C confirmed different corrosion mechanisms between Al 71 Zr 24 Fe 5 and Al 65 Zr 20 Fe 15 alloys. • High volta potential differences between al-zr and al-fe-zr phases were registered using SKPFM. • The Al 65 Zr 20 Fe 15 alloy was characterized by greater wear resistance in dry conditions and corrosive solutions. • Severe delamination and brittle fracture mechanism was identified for the Al 71 Zr 24 Fe 5 alloy after tribological tests. In this study, the structure of Al 65 Zr 20 Fe 15 and Al 71 Zr 24 Fe 5 alloys was studied using neutron diffraction and SEM with EDX maps. This paper presents the electrochemical measurement results performed in 3.5 % NaCl, H 3 BO 3 , and 3.5 % NaCl+H 3 BO 3 solutions at 40 °C. The Al 71 Zr 24 Fe 5 alloy showed higher corrosion resistance in acidic solution, whereas the Al 65 Zr 20 Fe 15 alloy was more resistant in 3.5 % NaCl+H 3 BO 3. Moreover, the corrosion behavior was described for the samples immersed for 8 weeks in 3.5 % NaCl at 40 °C. SKPFM indicated high Volta potential differences between Al-Zr and Al-Fe-Zr phases. Moreover, the higher wear resistance for Al 65 Zr 20 Fe 15 compared to the Al 71 Zr 24 Fe 5 alloy was demonstrated. [ABSTRACT FROM AUTHOR]

• [Mn(H 2 O) 6 ]2+ can accumulate in oriented sulfonate-functionalized silica thin films. • Their reaction with Na 2 WO 4 ●2H 2 O enables in situ' synthesis of a polyoxometalate. • The immobilized [Mn(H 2 O) 3) 2 (H 2 W 12 O 42)] n 6n- polyoxometalate is electroactive. • [Mn(H 2 O) 3) 2 (H 2 W 12 O 42)] n 6n- in silica exhibits good voltammetric operational stability. We present in this paper the 'in situ' preparation of manganese-containing polyoxotungstate [Mn(H 2 O) 3) 2 (H 2 W 12 O 42)] n 6n- (1) chains in vertically-oriented mesoporous silica thin films on indium-tin oxide (ITO) electrodes. Taking advantage of a soft sequential method allowing the formation of 1 inside the mesoporous matrix, we succeed in its 'in situ' formation according to two main steps: (i) a first one consisting of the immobilization of [Mn(H 2 O) 6 ]2+ in sulfonate-functionalized silica thin films; and (ii) a second one involving the reaction of the [Mn(H 2 O) 6 ]2+ moieties with Na 2 WO 4 2H 2 O. The electrochemical characterization of the functionalized materials obtained clearly demonstrates that the content of sulfonate groups in the starting films is a critical parameter to get the expected electroactive [Mn(H 2 O) 3) 2 (H 2 W 12 O 42)] n 6n- compound inside the silica nanochannels. The experimentally determined chemical composition of the films performed by X-ray Photoelectron spectroscopy (XPS) is in good agreement with the expected composition of 1 in the case of films obtained with the optimal content of sulfonate functions (i.e. , 5–6.5 % sulfonate with respect to silica). Energy Dispersive analysis of X-rays coupled with Transmission Electron Microscopy (TEM-EDX) carried out on the cross section of the films show that a uniform composition in terms of Mn/W ratio is obtained after the functionalization process. This confirms the formation of [Mn(H 2 O) 3) 2 (H 2 W 12 O 42)] n 6n- uniformly within the whole thickness of the silica film (i.e. , 80 nm), explaining also the long-range charge transfer reactions occurring through such insulating silica membrane. Using sulfonated silica films as template, we develop a robust 'in situ' synthesis strategy to assemble 1D linear polyoxotungstates onto ITO electrodes, exhibiting a stable electrochemical response once confined within the silica nanochannels. [ABSTRACT FROM AUTHOR]

An investigation of the solid electrolyte interphase (SEI) on hard carbon (HC) anodes in aprotic sodium batteries was carried out by post-mortem analyses. Electrodes cycled in 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIFSI), and N-trimethyl-N-butylammonium bis(fluorosulfonyl)imide (N 1114 FSI) ionic liquid electrolytes have been collected and studied: benchmark electrodes cycled in commercial organic solutions were examined for comparison purpose. The SEI composition and morphology of post-mortem HC electrodes were analyzed by X-ray Photoelectron Spectroscopy (XPS) and focused ion beam scanning electron microscopy (FIB-SEM) analysis. Overall, the HC electrodes cycled in carbonate-based electrolyte have shown thicker SEI mainly composed of organic compounds, whereas in ILs electrolytes they have shown thinner layer richer in inorganic species, such as NaF, Na 2 CO 3 , N-containing species, and "small" sulfide-based compounds, these improving the SEI interfacial properties towards the Na+ migration kinetics. Focusing on ILs based cell formulations, anodes cycled in the EMIFSI-based electrolyte shows several cracks on its surface. [ABSTRACT FROM AUTHOR]

A passive film serves as a first defense of any material against the attack of a corrosive environment for any material. So, it is essential to understand the parameters affecting the characteristics of the passive film. The present work focused on investigating the effect of tensile load during stress corrosion cracking (SCC) condition on the characteristics of the passive film developed on a TRIP Fe 39 Mn 20 Co 20 Cr 15 Si 5 Al 1 high entropy alloy (HEA) in a 3.5 wt.% NaCl solution at room temperature. A constant load of ∼25% of the yield strength was applied to a flat dog-bone-shaped tensile specimen for 24 h in a 3.5 wt.% NaCl salt environment. For comparison purposes, a specimen with no-load was kept in a salt solution under similar conditions. Electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) techniques were used for passive film characterization. EIS results revealed that the passive film deposited on the no-load and load conditions exhibited a dense and stable structure. However, the passive film deposited on the no-load specimen showed relatively better resistance to corrosion ions. XPS results indicated that the passive film deposited on the no-load and load specimens consisted of Cr rich oxide and hydroxide, forming a monolayer type of passivation film. Nonetheless, the passive film on the no-load specimen exhibited higher concentrations of Cr than the passive film on the loaded specimen. XPS depth profile results showed that the film thickness was relatively greater for the no-load specimen than for the loaded specimen. This study underscores the critical influence of tensile load on the degradation of passive film properties of the HEA. [ABSTRACT FROM AUTHOR]

Heteroatom doping of graphene oxide (GO) with phosphorous (P), and sulfur (S) was studied. In-situ grown binder-free electrodes of these doped and un-doped GO systems were developed via hydrothermal process. S-GO, P-GO, PS-GO, and un-doped hydrothermally treated GO (H-GO) electrodes were thoroughly investigated through physical and electrochemical characterization. The PS-GO electrode, comprising P (10.90 at%), S (0.3 at%), C (45.54 at%), O (36.36 at%), and Ni (2.38 at%) atoms, exhibited a mixed morphology of a few hundred nanometers doped GO flakes and dissolved Ni foam nanorods. Electrochemical analysis showed, this mixed morphology stimulates the charge storage ability of the PS-GO electrode and achieved a high specific capacity of 1218 C/g, compared to 647 C/g for H-GO at 1 mV/s. Electrochemical analysis revealed, charge was primarily stored through the capacitive charge storage mechanism, where only surface atoms are solely responsible for developing a double layer or facilitating redox reactions between electrode atoms and electrolyte ions. Additionally, the PS-GO electrode demonstrated an energy density of 76.94 Wh/kg at 1 A/g, which is much closer to that of batteries. We anticipate that PS-GO has the potential to be utilized as electrode material in modern energy storage devices. [ABSTRACT FROM AUTHOR]

• The MoS 2 /V 2 O 5 composite cathode is successfully constructed by one-step ball milling. • The unique in-situ conversion mechanism allows the obtained MoO 3 /V 2 O 5 cathode to achieve superior electrochemical performance. • The potentiality of rapidly constructing composite cathodes by ball milling is confirmed. Aqueous zinc-ion batteries have advantages of high safety, friendly environment, low cost, and can be applied to large-scale energy storage. To prepare high-performance cathode materials easily and quickly is still one of the development directions. Based on the principle that two-dimensional layered materials can be thinned layer-by-layer via mechanical force, the molybdenum disulfide (MoS 2)-based cathodes are prepared by one-step ball milling. The shear force and shockwave generated during ball milling effectively promote the preparation of MoS 2 /V 2 O 5 cathode materials. X-ray diffraction, Raman, and infrared tests confirm the presence of both MoS 2 and V 2 O 5 components in the prepared MoS 2 /V 2 O 5. The presence of metallic phase 1T-MoS 2 in the MoS 2 /V 2 O 5 is confirmed by X-ray photoelectron spectroscopy and transmission electron microscopy. Via a charging conversion mechanism, the obtained MoO 3 /V 2 O 5 cathode has a high capacity of 417.4 mAh g −1, good rate performance (83.6 mAh g −1 at 10 A g −1), high energy and power densities (83.6 Wh kg−1 at 10,032 W kg−1). This study provides a new idea for constructing two-dimensional material-based cathodes by ball milling. [Display omitted] [ABSTRACT FROM AUTHOR]

Composite materials with properties aimed at the additive manufacturing of affordable electrochemical sensors have received special attention in the scientific scenario. For this reason, we proposed a new composite material based on alumina oxide (Al 2 O 3) and graphite (Gpt) dispersed in polylactic acid (PLA) biopolymer. Various proportions between the materials were studied, and a better compromise between printability and electrochemical performance was obtained using Gpt/Al 2 O 3 /PLA (30:10:60% w/w). The electrodes were manufactured using a 3D pen, a portable, user-friendly, and low-cost tool. Characterizations by Raman and infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy indicated that Gpt and Al 2 O 3 were successfully incorporated into the PLA matrix. Preliminary studies using species with well-known electrochemical behavior revealed that Al 2 O 3 positively impacts the electrochemical response of the sensor. As a proof of concept, sulfamethoxazole (SMZ), a low-cost antibiotic widely used in beekeeping practices, was selected as the target analyte, and a simple, fast, and selective method using square wave voltammetry was proposed. Using the 3D-printed Gpt/Al 2 O 3 /PLA electrode, a wider linear range (2.0 to 40.0 μmol L−1), a 6.5-fold increase in sensitivity, limits of detection (LOD = 0.4 μmol L−1) and quantification (LOQ = 1.2 μmol L−1) were achieved compared to the Al 2 O 3 -free electrode (Gpt/PLA). In addition, the proposed sensor was selective against other antibiotics commonly used in beekeeping practices. Three honey samples were analyzed after simple dilution in 0.12 mol L−1 Britton-Robinson buffer, pH 7.0 (background electrolyte), and recoveries close to 100% as well as statistically comparable results from chromatographic analysis certified the accuracy and reliability of the analysis. The proposed approach is innovative and valuable in contributing to the advancement of additive manufacturing in electrochemical sensing, especially in the on-site analysis of antibiotic species in food, a public health challenge. [Display omitted] [ABSTRACT FROM AUTHOR]

• Materials studied lie in the Na 3/4 (Mn-Al-Ni)O 2 pseudo-ternary system. • P3/P2 phase fraction was manipulated by adjusting the calcination temperature. • Superior electrochemical performance of P3/P2 biphasic cathodes. • Absence of the P3 to O3 phase in the Al-substituted P3-type compounds. Layered oxide cathodes, a promising avenue for Na-ion batteries, hold the highest potential for commercialization. Herein, we delve into the structural and electrochemical properties of Al-substituted layered oxides in our quest to pinpoint the optimal cathode composition in the Na 3/4 (Mn-Al-Ni)O 2 pseudo-ternary system. The cathode materials investigated were synthesized in three distinct phase configurations, which include two monophasic configurations with P3 and P2-type structures and a third biphasic cathode with equal proportions of P3 and P2 phases. The fractions of the P3 and P2 type phases in the cathode materials were manipulated by adjusting the calcination temperature. The varying concentration of Mn3+ and Mn4+, confirmed by X-ray photoelectron spectroscopy, was found to impact the cyclic stability of these materials significantly. During electrochemical testing, the P3 cathodes showed impressive rate performance and exhibited an excellent specific capacity of 195 mAh g−1 at 0.1C. Regarding cyclic performance, the biphasic cathodes consistently outperformed their monophasic counterparts, with P3/P2-Na 0.75 Mn 0.50 Ni 0.25 Al 0.25 O 2 exhibiting 82 % capacity retention after 300 cycles. Analysis of operando Synchrotron XRD data revealed an absence of P3 to O3 type phase transition in the cathodes even at low voltages where large structural variations to the unit cell structure were observed. The absence of P3 to O3 transformations and the superior electrochemical performance of Na 0.75 Mn 0.50 Ni 0.25 Al 0.25 O 2 underlines the importance of Al substitution and P3/P2 biphasic structure in enhancing the electrochemical performance of layered oxides. [ABSTRACT FROM AUTHOR]

Laser-induced graphene (LIG) electrodes have become popular for electrochemical sensor fabrication due to their simplicity for batch production without the use of reagents. The high surface area and favorable electrocatalytic properties also enable the design of small electrochemical devices while retaining the desired electrochemical performance. In this work, we systematically investigated the effect of LIG working electrode size, from 0.8 mm to 4.0 mm diameter, on their electrochemical properties, since it has been widely assumed that the electrochemistry of LIG electrodes is independent of size above the microelectrode size regime. The background and faradaic current from cyclic voltammetry (CV) of an outer-sphere redox probe [Ru(NH 3) 6 ]3+ showed that smaller LIG electrodes had a higher electrode roughness factor and electroactive surface ratio than those of the larger electrodes. Moreover, CV of the surface-sensitive redox probes [Fe(CN) 6 ]3– and dopamine revealed that smaller electrodes exhibited better electrocatalytic properties, with enhanced electron transfer kinetics. Scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy showed that the physical and chemical surface structure were different at the electrode center versus the edges, so the electrochemical properties of the smaller electrodes were improved by having rougher surface, more density of the graphitic edge planes, and more oxide-containing groups. The difference could be explained by the different photothermal reaction time from the laser scribing process that causes different stable carbon morphology to form on the polymer surface. Our results give a new insight on relationships between surface structure and electrochemistry of LIG electrodes and are useful for designing miniaturized electrochemical devices. [Display omitted] [ABSTRACT FROM AUTHOR]

• The N and S heteroatom doping can adjust the O vacancy percentage of Ti-WO 3 and Nb-h-WO 3. • Doped transition metal oxides greatly enhance the actual electrochemical activity of graphite felt. • Doped transition metal oxides are advantageous in reducing the capacity decay of AORFBs. In this study, a graphite felt (GF) electrode was modified with N and S heteroatoms before being loaded with Ti-doped or Nb-doped WO 3 to produce Ti-WO 3 /GF-N-S and Nb-WO 3 /GF-N-S electrodes. X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy were used to analyze the crystal structure, morphology, and elemental state of the modified GF electrodes and investigate the impact of nonmetallic and metallic element doping. The influence of metal doping on the electronic distribution of the oxide was determined using first-principle calculations. The electrochemical properties of the modified GF were studied using cyclic voltammetry, electrochemical impedance spectroscopy, and single-cell tests. The results showed that Ti or Nb doping changed the energy band structure, bond length, and bond angle in the WO 3 crystal and formed O vacancies. The chemical properties of Ti and Nb resulted in different numbers of O vacancies for the two doped-WO 3.The doping of N and S heteroatoms on the carbon fibres altered the O vacancy concentration of WO 3. The synergism between the two doping methods accelerated electron transfer in the anthraquinone redox reaction. In addition, the N-containing functional groups provide lone-pair electrons, which accelerate electron transfer and anthraquinone adsorption. Therefore, compared to the pristine GF, the discharge capacities of the Ti-WO 3 /GF-N-S and Nb-h-WO 3 /GF-N-S graphite GF electrodes increased by 58 % and 41 %, respectively, and the Nb-h-WO 3 /GF-N-S graphite GF electrodes exhibited a good capacity retention rate. This study broadens the practical applications of aqueous anthraquinone redox flow batteries. [ABSTRACT FROM AUTHOR]

• Electrochemistry of Cu (II) & As (III) with Au(111) nanofilm. • Linear stripping voltammetry in Cu & As solutions results in Cu-As alloy formation. • Cu-As alloy formation likely during voltage step deposition. • Sequential deposition of Cu then As during cyclic voltammetry impedes As deposition. • Formation of Cu-As alloy severely impacts ability to detect As at Au(111) surface. The ability to detect trace concentrations of arsenite, As (III), in real water solutions is impacted by co-contamination of other metals and co-occurring ions. The presence of copper (II) ions are the most likely co-contaminant in natural waters to interfere with electrochemical As (III) detection, due to the close oxidation potentials of Cu (II) and As (III). The use of well-oriented ultraflat Au(111) thin film electrodes provided increased peak separation and sensitivity for electrochemical deposition and oxidation of Cu (II) and As (III) in 0.5 M sulfuric acid compared to an Au wire electrode. However, mixtures of Cu (II) and As (III) altered the oxidation peak positions during both cyclic voltammetry (CV) and linear stripping voltammetry (LSV) analysis. Calibration curves using the standard additions method in trace concentrations were conducted for Cu, As, and Cu & As solutions. Sweeping the potential at 10 mV s−1 during CV in Cu & As mixtures resulted in a sequential deposition condition where a layer of Cu inhibited co-deposition of As to the electrode. In contrast, the rapid potential stepping of LSV to a potential where Cu and As reduction simultaneously occurs produced a peak profile different from Cu or As alone. A larger oxidation peak during LSV was also observed when both Cu and As were present. X-ray photoelectron spectroscopy indicates a Cu-As alloy is formed on the surface after LSV deposition. SYNOPSIS: Analysis of Cu (II), As (III) and Cu (II) & As (III) mixtures suggests that a Cu 3 As intermetallic phase is formed during LSV which impacts trace As detection even in trace Cu conditions. This has important implications for the ability to determine As concentrations near the MCL of 10 µg L−1 in natural water systems which may contain Cu (II) and other co-contaminants. [ABSTRACT FROM AUTHOR]

Most Zr conversion coatings are prepared on Al alloys, with Al3+ from the substrate contributing significantly to the film growth process. Thus, the effect of Al3+ on the electrochemical characteristics, surface microstructure and film-formation mechanism of Zr-based conversion coatings on old- rolled steel (CRS) substrates was investigated by growing the coatings with and without Al3+ as an additive. Electrochemical tests indicated that the anticorrosion performance of the Zr-Al coatings prepared in the presence of Al3+ was greatly superior to that of Zr conversion coatings obtained in the absence of Al3+. Field-emission scanning electron microscopy and X-ray photoelectron spectroscopy analysis indicated that adding of Al3+ in the conversion bath changed the surface microstructure of the Zr coating, greatly promoted the deposition of Zr and F on the CRS substrate and increased the film thickness and density. Both coatings were embedded into the etched CRS substrates. The presence of Al3+ additive induced the formation of different coating components. The Zr coating mainly consisted of ZrO 2 and some FeF x , whereas the Zr-Al coatings comprised of ZrO 2 , ZrO x F y , Al 2 O 3 , AlF x and some FeF x. The present study results confirm the key role of Al3+ as an additive in the film formation and growth process of Zr coatings and its effect on enhancing the anticorrosion performance of CRS substrates in NaCl solutions. [ABSTRACT FROM AUTHOR]

• An expected SnO 2 @CuO/CF heterostructure material is synthesized. • p-n heterojunction enhances the adsorption of H 2 O 2 and benefits sensing properties. • Cost-effective H 2 O 2 electrochemical sensor with excellent performance is obtained. • The developed sensor has good biocompatibility for real-time detection of H 2 O 2 released by living cells. Hydrogen peroxide (H 2 O 2) is a major messenger molecule in cellular signal transduction. It is critical to detect cellular secreted H 2 O 2 in situ for clinical diagnosis and biomedical research. Therefore a simple, fast, sensitive, and cost-effective hydrogen peroxide detection method is needed. In this study, copper foam (CF) was used as copper source and conductive substrate, the electrochemical sensor SnO 2 @CuO/CF is prepared to detect H 2 O 2 secreted by living cells. High resolution transmission electron microscopy (HRTEM), X-ray diffraction, Mott Schottky curves and X-ray photoelectron spectroscopy demonstrate the successful formation of SnO 2 @CuO heterostructure. Theoretical calculations confirm that SnO 2 @CuO heterostructure facilitates the adsorption of H 2 O 2. The designed SnO 2 @CuO/CF sensor shows good sensing performance for H 2 O 2. Under optimal conditions, the designed sensor shows a relatively wide linear range to H 2 O 2 concentration from 1 μM to 13.88 mM, with high sensitivity (5100 μA·mM−1·cm−2) and low detection limit (0.13 μM). Cytotoxicity experiments prove that the sensor has good biocompatibility and the prepared sensor is successfully used to detect H 2 O 2 released by HeLa cells. With superior sensitivity, anti-interference ability, and reproducibility, SnO 2 @CuO /CF shows the potential application of H 2 O 2 monitoring in the field of biomedical and clinical diagnosis. This study provides a new platform for the development of highly sensitive H 2 O 2 electrochemical sensors in practical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

In this research, we introduce a pioneering approach for enhancing the electrocatalytic performance of counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) by synthesizing Pt/CeO x hybrid nanocatalysts through a refined polyol reduction technique. This method facilitates the accurate production of Pt nanoparticles supported on ceria, leveraging their strong metal-oxide interactions. X-ray photoelectron spectroscopy (XPS) was employed to confirm the co-presence of both metallic and oxidized states of Pt, as well as the mixed valence states of ceria within these nanostructures. The electrocatalytic behavior of these nanocatalysts was rigorously evaluated using cyclic voltammetry (CV), Tafel polarization analyses, and electrochemical impedance spectroscopy (EIS). We identified an optimal Pt/Ce ratio of 1:0.1, which significantly enhanced the kinetics of the iodine reduction reaction (IRR), a crucial factor for efficient DSSC operation. Photovoltaic testing under one-sun AM 1.5 G conditions demonstrated that DSSCs with the optimized Pt/CeO x CEs exhibited a 10 % increase in power conversion efficiency (PCE) comparted to control cells. This study highlights the effectiveness of Pt/CeO x hybrid nanocatalysts in improving bifacial DSSC performance, combining the catalytic strengths of platinum with the unique properties of ceria. [ABSTRACT FROM AUTHOR]

Microfiber electrodes derived from graphite felt were used for the evaluation of charge transfer kinetic constants in a ferrocyanide-based electrolyte, which is a model system for redox flow batteries. Cyclic voltammetry experiments were performed in the presence of 10−2 M or 0.5 M Fe(CN) 6 4−. Within this framework, microfiber electroanalysis allowed for the quantitative assessment of four distinct activation protocols for graphite felt: thermal treatment under CO 2 at 850 °C, nitric acid immersion at 70 °C, exposure to Fenton's reagent at ambient temperature, and treatment with urea under atmospheric conditions at 550 °C. This analytical method enabled a hierarchical categorization of the various activation techniques, aiding in the identification of optimal conditions that yield the highest charge transfer kinetics for the ferrocyanide electrolyte. Additionally, the methodology provided insights into the temporal degradation or aging of these activated materials. These empirical observations are discussed alongside characterization data obtained from X-ray Photoelectron Spectroscopy (XPS), Raman spectrometry, and capacitive current measurements. [ABSTRACT FROM AUTHOR]

• Formation of bi-layered films with physisorbed outer and chemisorbed inner layers. • 2-MBI bonding by N to metallic and oxidized Cu, S also involved on metallic Cu. • Formation of Cu(I)−2-MBI complex promoted by cathodic conversion of native Cu oxide. • Increased complex formation owing to Cu(I) ions generated by anodic oxidation. • Cu dissolution inhibited depending on pre-treatment used for interface formation. The interfacial bonding and the layered structure of 2-mercaptobenzimidazole (2-MBI) organic films adsorbed on electrochemically controlled copper surfaces and their corrosion inhibition effects in acidic chloride aqueous solution were investigated using an integrated approach of electrochemical methods and advanced surface analyses by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. It is shown that organic films formed on the copper surfaces are bi-layered with a chemisorbed inner layer and a physisorbed outer layer. In the chemisorbed inner layer, 2-MBI is bonded primarily by its nitrogen atoms with metallic and oxidized copper surfaces. Sulphur atoms are also involved in the bonding mechanism when metallic copper is directly accessible to the 2-MBI molecules. The initial presence of native copper oxides at the interface promotes the formation of Cu(I)-2-MBI metal-organic complexes in the chemisorbed inner layer using cathodic reduction to dissociate the oxide. Metal-organic complexes also form upon anodic polarisation due to Cu(I) ions generated by oxidation of the copper metal. 2-MBI effectively inhibits copper anodic dissolution in varying degrees, between 84% and 93%, depending on the pre-treatment used for the formation of the organic bi-layers. An enhanced protection of the substrate is obtained by adsorbing the 2-MBI inhibitor on an initially oxide-free surface, which is achieved by cathodic pre-treatment in absence of the inhibitor followed by 1 hour exposure to the inhibitor. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effects of electrochemically generated hydrogen on the passivation behaviour of Ni–Ti alloy surfaces. Hydrogen charging via galvanostatic polarisation increased the passive current density during cyclic potentiodynamic polarisation experiments. Electrochemical impedance spectroscopy and Mott–Schottky analyses revealed an increase in the electrochemical conductivity of the film, indicating that hydrogen charging increased the donor density. Changes in the compositions were detected by Auger electron spectroscopy and X-ray photoelectron spectroscopy. Scanning transmission electron microscopy revealed film degradation after hydrogen charging. These results demonstrate that the electrochemical conductivity of the passive film increased owing to hydrogen absorption. [ABSTRACT FROM AUTHOR]

Alkaline oxygen reduction reaction (ORR) presents an important role for energy conversion technologies and requires the development of an efficient electrocatalyst. Pt-based catalysts provide suitable activity; however, Pt production accessibility and high costs create hurdles to their commercial implementation. Fe coordinated within N-doped carbon materials (Fe N C) are a promising alternative due to their high ORR catalytic activity, although the currently commercially available Fe N C materials rely on harsh synthetic protocols which can lead to increased environmental impacts. In this work we target this issue by taking advantage of an oily sludge waste currently generated in refineries to synthesize Fe N C materials, thus, avoiding the environmental impact caused by the management of this waste. The solid particles within oily sludge, which present a high concentration of C and Fe, were combined by different nitrogen sources and pyrolyzed at high temperatures. The prepared materials present a hierarchical pore structure with surface areas up to 547 m2 g−1. X-ray photoelectron spectroscopy analysis found that the impregnation of N using phenanthroline promotes the formation of pyridinic-N structures, which enhances the ORR performance compared to melamine doping. Additional doping of Fe with phenanthroline results in an ORR mass activity of 1.23 ± 0.04 A g FeNC −1 at 0.9 V RHE, iR-free in a rotating disc electrode (0.1 M KOH). This catalyst also shows a lower relative loss in activity at 0.9 V RHE after 8000 cycles in O 2 -saturated conditions compared to a commercial FeNC catalyst, PMF D14401, (−63.5 vs −69 %, respectively), demonstrating promise as a cheap and simple route to Fe N C catalysts for alkaline ORR. [Display omitted] [ABSTRACT FROM AUTHOR]

• Efficient method to immobilize biomolecules to prepare several impedimetric biosensor. • Triglyceride biosensor with low detection limit and high sensitivity. • Biosensor prepared by sol-gel method and dip coating designed using a sequence of films. • Silica-zirconia, gold nanoparticles and silica-lipase films deposited on FTO glass. • The enzyme stays entrapped in silica film maintaining operational stability. A novel electrochemical sensing platform was created using the formation of a sequence of films, over a conductive fluorine-doped tin oxide glass (FTO), obtained using the sol-gel method and the dip coating technique. Firstly, thin films of silica-zirconia mixed oxides were deposited, in sequence an ionic silsesquioxane film stabilizing and controlling the size of gold nanoparticles (6.5 ± 2.4 nm) was settled, and after the lipase enzyme, obtained from Candida rugosa, was entrapped into a silica film maintaining its operational stability. The films were characterized by scanning electron microscopy (SEM) with EDX, UV–Vis spectroscopy and X-ray photoelectron spectroscopy (XPS). The thickness of each film on the FTO glass was evaluated by optical profilometry. The presence of the enzyme on the platform was confirmed by cyclic voltammetry with the ρ-nitrophenyl palmitate method. This platform was applied successfully as a biosensor for tributyrin (TB) determination by electrochemical impedance spectroscopy EIS, showing low limit of detection (LD) of 1.86 μmol L−1 and high sensitivity of 5.37 μΩ μmol−1 L. The biosensor presented a low K M app value of 22.69 μmol L − 1 and the V max app value of 85.57 μmol L−1 min−1 suggesting that the enzyme, immobilized with this method retained activity promoting a fast enzymatic reaction with the TB. [ABSTRACT FROM AUTHOR]

In pursuit of sustainable hydrogen production, alkaline water electrolysis offers fossil-free technology for generating hydrogen. Exploring new non-precious metal electrocatalysts plays a crucial role in this endeavor. Herein, we investigate a trimetallic NiFeMo material on a nickel foam support, serving as a bifunctional electrocatalyst for catalyzing both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Scanning electron microscopy reveals a nanosheet array structure with a uniform distribution of Ni, Fe, and Mo compounds on the electrode surface. Furthermore, the chemical surface composition of the pristine and spent electrodes is elucidated via x-ray photoelectron spectroscopy, displaying primarily oxidized species on the electrocatalyst surface. Bifunctional performance is assessed in a three-electrode setup, unveiling overpotentials of 70 mV for the HER and 140 mV for the OER, in a 30 wt% KOH electrolyte at 90 °C. Additionally, in an industrial electrolysis cell, the activated electrode is evaluated as cathode and anode for 28 days, which decreased the overpotential of 330–350 mV at 200 mA cm geo −2 compared with pristine nickel foam. The performance increase of the electroplated coating is attributed to the increased surface area and enhanced intrinsic activity. The electrolysis cell experiences a ∼6 % voltage loss during the experiment, indicating its robustness and suitability for industrial alkaline electrolysis applications. [ABSTRACT FROM AUTHOR]

• Electrodeposited Ti and Ti foils were anodized to obtain TiO 2 nanotube (TNT) layers. • Two different thicknesses of TNT layers were prepared and extensively compared. • No morphological differences were found between layers on the two substrates. • Preferential (101) orientation of anatase revealed for layers on electrodeposited Ti. • Enhanced photo-electrochemical behavior for TNT layers on electrodeposited Ti. This study conducted a deep investigation of TiO 2 nanotube (TNT) layers of two different thicknesses anodically grown on electrodeposited Ti films. The Ti films were grown from molten salts on Ni foils. The structure of the starting metals was compared by XRD (X-Ray Diffraction) and EBSD (Electron Backscatter Diffraction analyses), which showed a strong orientation towards the titanium (101) for the electrodeposited substrate, compared to the rather polycrystalline structure of the rolled Ti. The photoelectrochemical and electrochemical properties of 1 μm and 5 μm thick TNT layers anodically grown on these substrates were examined and compared with TNT layers of the same thickness. No significant morphological and compositional differences were found using SEM (Scanning Electron Microscopy) and XPS (X-ray Photoelectron Spectroscopy) between the TNT layers grown on the two substrates. However, higher photocurrent densities and ICPE values were observed for TNT layers grown on electrodeposited Ti. An in-depth investigation using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) analyses showed increased conductivity of the TNT layers produced on electrodeposited Ti compared to their counterparts. The carrier density (N D) for the TNT layers on electrodeposited Ti, calculated from Mott-Schottky measurements, showed a higher doping level than the TNT layers grown on Ti foils. This increase in N D results in more optimal photoelectrochemical performance of the TNT layers grown on electrodeposited Ti. All in all, the results presented herein pave the way for the use of electrodeposited Ti, with all its inherent benefits, and allow the further study of its promising properties in a wide range of applications. [ABSTRACT FROM AUTHOR]

Silicon monoxide (SiO), which has been verified as a potential anode material, can improve the energy density of Li-ion batteries (LIBs). These LIBs are crucial for the advancement of electric vehicles. However, the commercial application of SiO is severely limited due to poor initial Coulombic efficiency (ICE). In this study, we present a novel concept to enhance the ICE of silicon oxide-based anodes by collaboratively leveraging two distinct reaction theories: disproportionation reaction and the reaction between acidic oxide and alkali. Based on this concept, we utilize a chemical disproportionation-driven Li metal-free prelithiation method, enabling the in-situ growth of microcrystalline silicon and lithium silicate within amorphous silicon oxide, which bears a striking resemblance to pitaya seeds. This reaction yields unique lithium silicate and nano/micro-structured silicon surrounded by SiO (Si–SiO–Li x SiO y multicomponents, PD-SiO). This can be demonstrated via transmission electron microscopy (TEM), Electron energy loss spectroscopy (EELS) or X-ray photoelectron spectroscopy (XPS). The reaction product, PD-SiO, exhibits remarkable properties, including high ICE (82.5 %), high charging capacity (1419 mAh g–1), and highly stable cycling performance (94.6 % capacity retention after 200 cycles at 0.5 A g–1). This study offers a new approach to enhance the initial Coulombic efficiency of silicon monoxide. [ABSTRACT FROM AUTHOR]

Herein, we report the surface treatment on Zr4+/Al3+ codoped α-Fe 2 O 3 photoanode for high-performance photoelectrochemical water splitting. A high-temperature quenching exhibits the Zr4+/Al3+ codoping in α-Fe 2 O 3 photoanode without damaging morphology. The presence of Zr4+/Al3+ codoping shows a cathodic shift in onset potential, but lack of increment in photocurrent reveals the major role of passivation and the minimum doping effect of aluminum. Additionally, CoO x cocatalyst exhibits increment in photocurrent with the greater cathodic shift in onset potential than the pristine α-Fe 2 O 3 nanorods. The CoO x surface-reworked Zr4+/Al3+ codoped α-Fe 2 O 3 photoanode displays the highest photocurrent of 1.5 mA/cm2 at 1.23 V vs. RHE (76% increment over the pristine α-Fe 2 O 3) and 0.7 mA/cm2 at 1.0 V vs. RHE (102% increment over the pristine α-Fe 2 O 3). The systematic characterization carried out using x-ray diffraction and scanning electron microscopy confirms that after Zr4+/Al3+ codoping, and surface treatment, the crystalline structure, and morphology of the photoanodes remains unchanged. X-ray photoelectron spectroscopy confirmed the existence of Zr4+/Al3+ codopants in the hematite nanostructure. The electrochemical properties of the photoanode suggest that Al3+ and Zr4+ codoping, as well as surface treatment with CoO x , cocatalyst lowers charge transfer resistance across the FTO/hematite interface, and hematite/electrolyte interface. This designs not only lowers onset potential but also offers the blueprint for the development of an efficient catalyst for solar water oxidation. CoO x surface-reworked Zr4+/Al3+ codoped α-Fe 2 O 3 photoanode displays the 102% increment in PEC performance than pristine α-Fe 2 O 3 at 1.0 V vs. RHE. Image 1 • Zr4+/Al3+-codoped Fe 2 O 3 photoanode synthesized by hydrothermal method. • CoO x co-catalyst improves the OER kinetics via surface reworking. • Optimum photoanode exhibits 102% increase in photocurrent density than Fe 2 O 3. • The charge transfer mechanism in 6% Zr + 6% Al + 15 mM Co is also proposed. [ABSTRACT FROM AUTHOR]

A potential-responsive 2-2′-dithiodibenzoic acid (DTSA)/Polyaniline (PANI) hybrid film with high ion-exchange capability and selectivity to cadmium ions was successfully fabricated on electrode by a one-step cyclic voltammetry (CV) method. S–S bonds in the DTSA serve as a gate that can be controllably opened and closed to let cadmium ions get in and out of the hybrid film when changing its redox state, and the PANI mainly enhanced the conductivity of the hybrid film. The working mechanism of the film is proposed and identified via the electrochemical quartz crystal microbalance (EQCM) technique, X-ray photoelectron spectroscopy (XPS), Raman and density functional theory (DFT) computations. As a result, the obtained hybrid film exhibited high selectivity towards cadmium ions even in the presences of other cations. More interestingly, over 240% of its initial capacity was retained after 25 consecutive cycles and maintained in the following cycles. Furthermore, the regeneration rate of the hybrid film retains 99% of its initial value even after 30 cycles. It is expected that such a potential-responsive film can be applied for the removal and recovery of cadmium ions from wastewater in various industrial processes. Image 1 • S–S bonds can be controllably to let Cd2+ get in and out of the hybrid film. • The obtained hybrid film exhibited a high selectivity towards Cd2+ ions. • The regeneration rate of film retains 99% of its initial value after 30 cycles. • It is function as the ion-probe which accelerates the uptaking rate of cadmium. [ABSTRACT FROM AUTHOR]