Search Results (599)

The widespread adoption of sodium-ion batteries (SIBs) remains constrained by the inherent limitations of conventional anode materials, particularly their inadequate electronic conductivity, limited active sites, and pronounced structural degradation during cycling. To overcome these limitations, we propose a novel redox engineering approach to fabricate oxygen-vacancy-rich SnO₂ dots anchored on reduced graphene oxide (rGO), which are encapsulated within N-doped carbon nanofibers (denoted as ov-SnO₂/rGO@N-CNFs) through electrospinning and subsequent carbonization. The introduction of rich oxygen vacancies establishes additional sodium intercalation sites and enhances Na⁺ diffusion kinetics, while the conductive N-doped carbon network effectively facilitates charge transport and mitigates SnO₂ aggregation. Benefiting from the well-designed architecture, the hierarchical ov-SnO₂/rGO@N-CNFs electrode achieves remarkable reversible specific capacities of 351 mAh g⁻¹ after 100 cycles at 0.1 A g⁻¹ and 257.3 mAh g⁻¹ after 2000 cycles at 1.0 A g⁻¹ and maintains 177 mAh g⁻¹ even after 8000 cycles at 5.0 A g⁻¹, demonstrating exceptional long-term cycling stability and rate capability. This work offers a versatile design strategy for developing high-performance anode materials through synergistic interface engineering for SIBs. Full article

MXene materials have great potential for energy storage applications, owing to their unique two-dimensional structure, exceptional electrical conductivity, and versatile surface chemistry. However, the practical utilization of pristine MXenes is hindered by several intrinsic limitations, such as interlayer restacking (which impedes ion diffusion), susceptibility to oxidation in aqueous and oxygen-rich environments, instability of surface functional groups, and suboptimal electrical conductivity. The structural engineering and surface modification strategies of MXenes were reviewed in this manuscript. The modification approaches include intercalation, surface functionalization, doping, and composite engineering. The insights presented herein aim to promote the development and practical application of MXene-based materials in next-generation energy storage devices. Full article

To date, one of the main problems associated with the engineering application of metallic materials is corrosion protection. To increase their durability and reduce damage, a variety of protection methods have been studied and applied. In recent decades, coating techniques have become increasingly important. Among these coatings, Layered Double Hydroxides (LDHs) have shown unique properties, such as ion exchange, high adhesion, and hydrophobicity, particularly useful for biomedical applications. In this review, after a detailed exposition of the LDHs’ synthesis processes, the most recent corrosion protection methods are illustrated. Intercalation of corrosion inhibitors and release kinetics of intercalates are presented. Although this work is mainly focused on laboratory-scale investigations and fundamental research, the problems inherent to large-scale industrial manufacturing and application are outlined and briefly discussed. Full article

This study investigates the performance of Cu-intercalated V₃O₇·H₂O (CuVOH) as a cathode material for aqueous zinc-ion batteries (AZIBs). Density Functional Theory (DFT) calculations were conducted to explore the effects of Cu²⁺ incorporation and structural water on the electrochemical performance of VOH. The results indicated that Cu²⁺ and structural water enhance Zn²⁺ diffusion by reducing electrostatic resistance and facilitating faster transport. Based on these insights, CuVOH nanobelts were synthesized via a one-step hydrothermal method. The experimental results confirmed the DFT predictions, demonstrating that CuVOH exhibited an initial discharge capacity of 336.1 mAh g⁻¹ at 0.2 A g⁻¹ and maintained a high cycling stability with 98.7% retention after 1000 cycles at 10 A g⁻¹. The incorporation of Cu²⁺ pillars and interlayer water improved the structural stability and Zn²⁺ diffusion, offering enhanced rate performance and long-term cycling stability. The study highlights the effective integration of computational and experimental methods to optimize cathode materials for high-performance AZIBs, providing a promising strategy for the development of stable and efficient energy storage systems. Full article

We present a brief overview of the field of charge density waves (CDW) in condensed systems with focus set to the underlying mechanisms behind the CDW ground state. Our intention in this short review is not to count all related facts from the vast volume of literature about this decades-old and still developing field, but rather to pinpoint the most important, mostly theoretical ones, presenting the development of the field. Starting from the “early days”, mainly based on weakly coupled, chain-like quasi-1D systems and Peierls instability, in which the Fermi surface nesting has been the predominant and practically paradigmatic mechanism of the CDW ground state stabilisation, we track the change in paradigms while entering the field of layered quasi-2D systems, with Fermi surface far away from the nesting regime, in which rather strong, essentially momentum-dependent interactions and particular reconstructions of the Fermi surface become essential. Examples of real quasi-1D materials, such as organic and inorganic conductors like Bechgaard salts or transition metal trichalcogenides and bronzes, in which experiment and theory have been extremely successful in providing detailed understanding, are contrasted to layered quasi-2D materials, such as ${\mathrm{high-T}}_c$ superconducting cuprates, intercalated graphite compounds or transition metal dichalcogenides, for which the theory explaining an onset of the CDWs constitutes a frontier of this fast-evolving field, strongly boosted by development of modern ab initio calculation methods. Full article

Cyclic voltammetry (CV) is an accessible, readily available, non-expensive technique that can be used to search for the interaction of compounds with DNA and detect the strongest DNA-binding from a set of compounds, therefore allowing for the optimization of the number of cytotoxicity assays. Focusing on this electrochemical approach, the study of twenty-seven camphorimine silver complexes of six different families was performed aiming at detecting interactions with calf thymus DNA (CT-DNA). All of the complexes display at least two cathodic waves attributed respectively to the Ag(I)→Ag(0) (higher potential) and ligand based (lower potential) reductions. In the presence of CT-DNA, a negative shift in the potential of the Ag(I)→Ag(0) reduction was observed in all cases. Additional changes in the potential of the waves, attributed to the ligand-based reduction, were also observed. The formation of a light grey product adherent to the Pt electrode in the case of {Ag(OH)} and {Ag₂(µ-O)} complexes further corroborates the interaction of the complexes with CT-DNA detected by CV. The morphologic analysis of the light grey material was made by scanning electronic microscopy (SEM). The magnitude of the shift in the potential of the Ag(I)→Ag(0) reduction in the presence of CT-DNA differs among the families of the complexes. The complexes based on {Ag(NO₃)} exhibit higher potential shifts than those based on {Ag(OH)}, while the characteristics of the ligand (^AL-Y, ^BL-Y, ^CL-Z) and the imine substituents (Y,Z) fine-tune the potential shifts. The energy values calculated by docking corroborate the tendency in the magnitude of the interaction between the complexes and CT-DNA established by the reaction coefficient ratios (Q_[Ag-DNA]/Q_[Ag]). The molecular docking study extended the information regarding the type of interaction beyond the usual intercalation, groove binding, or electrostatic modes that are typically reported, allowing a finer understanding of the non-covalent interactions involved. The rationalization of the CV and cytotoxicity data for the Ag(I) camphorimine complexes support a direct relationship between the shifts in the potential and the cytotoxic activities of the complexes, aiding the decision on whether the cytotoxicity of a complex from a family is worthy of evaluation. Full article

Sodium-ion batteries (SIBs) have been considered as a promising alternative to lithium-ion batteries (LIBs) for large-scale energy storage. However, the commercial graphite anode is not suitable for SIBs due to its low Na⁺ ion storage capability. Currently, hard carbon has been considered a promising anode material for SIBs. Herein, the surface porousized hard carbon anode materials have been prepared by using hydrogen peroxide (H₂O₂) with a hydrothermal method (HC-HO) and utilized as the anode material for SIBs. The porous structure of HC-HO provides more storage space for Na⁺ ions and enhances the intercalation/deintercalation reversibility and diffusion rate of Na⁺ ions. Moreover, HC-HO can effectively alleviate the particle volume expansion and generate a thin and stable SEI film during charge/discharge processes. Thus, the HC-HO exhibits a high reversible capacity (314.4 mAh g⁻¹ with an ICE of 92.3% at 0.05 C), excellent rate performance (241.4 mAh g⁻¹ at 3 C), and outstanding cycling stability (a capacity retention of 78.6% after 500 cycles at 1 C). The preparation of porous hard carbon provides new ideas for the future development direction of hard carbon. Full article

The g-C₃N₄/TiO₂ intercalation composite material was successfully synthesized and used as the adsorbent in the hemoperfusion device. Then, the cytotoxicity and hemolysis rate were studied. The experimental results proved that g-C₃N₄/TiO₂ was non-toxic to cells and would not cause hemolysis. The adsorption and removal performance of the composite material for bilirubin (BR) was explored as well. The maximum adsorption capacity for BR was 850 mg·g⁻¹. Compared with the chemical hemoperfusion adsorbent coconut shell activated carbon (AC), the g-C₃N₄/TiO₂ material presented excellent adsorption performance. Furthermore, SEM, infrared spectroscopy, XPS and other characterizations results indicated that g-C₃N₄/TiO₂ has an effective adsorption effect on bilirubin, and the main adsorption mechanism is chemical adsorption. This study demonstrates that g-C₃N₄/TiO₂ may be a potential adsorbent for hemoperfusion in the treatment of hyperbilirubinemia. Full article

The possibility of reinforcing polymeric matrices with multifunctional fillers for improving structural and functional properties is widely exploited. The compatibility between the filler and the polymeric matrix is crucial, especially for high filler content. In this paper, polymeric matrices of Nylon 6,6 with pyrene chains were successfully synthesized to improve the compatibility with carbonaceous fillers. The compatibility was proven using graphite as a carbonaceous filler. The different properties, including thermal stability, crystallinity, morphology, and local mechanical properties, have been evaluated for various filler contents, and the results have been compared to those of synthetic Nylon 6,6 without pyrene chain terminals. XRD results highlighted that the compatibilization of the composite matrix may lead to an intercalation of the polymeric chains among the graphite layers. This phenomenon leads to the protection of the polymer from thermal degradation, as highlighted by the thermogravimetric analysis (i.e., for a filler content of 20%, the beginning degradation temperature goes from 357 °C for the non-compatibilized matrix to 401 °C for the compatibilized one and the residual at 750 °C goes from 33% to 67%, respectively. A significant improvement in the interphase properties, as proven via Atomic Force Microscopy in Harmonix mode, leads to a considerable increase in local mechanical modulus values. Specifically, the compatibilization of the matrix hosting the graphite leads to a less pronounced difference in modulus values, with more frequent reinforcements that are quantitatively similar along the sample surface. This results from a significantly improved filler distribution with respect to the composite with the non-compatibilized matrix. The present study shows how the thermoplastic/filler compatibilization can sensitively enhance thermal and mechanical properties of the thermoplastic composite, widening its potential use for various high-performance applications, such as in the transport field, e.g., for automotive components (engine parts, gears, bushings, washers), and electrical and electronics applications (heat sinks, casing for electronic devices, and insulating materials). Full article

In the present work, we address the theory of the lattice-gas model to the study of intercalation materials by using a novel kinetic Monte Carlo (kMC) algorithm for the simulation of an electrochemical method of everyday use in R&D laboratories: constant-current chrono-potentiometric measurements. The main aim of the present approach is to show how to use these atomistic simulations to study intercalation materials used as electrodes in alkali-ion batteries under galvanostatic conditions. The framework can be applied to related areas. To accomplish this, we explain the electrochemical background, linking the continuum scale with the microscopic events of discrete simulations. A comprehensive theoretical approach developed in a previous work is used as a reference for this aim. The galvanostatic kMC algorithm proposed is explained in detail and is subject to validation tests. The present work may serve as a basis for future implementations of kMC under galvanostatic conditions to study phenomena beyond the applicability of simulations on the continuum scale. Full article

Sodium-ion batteries are renowned for their abundant reserves, cost-efficiency, safety, and eco-friendliness and are prime candidates for large-scale energy storage applications. The development of cathode materials plays a crucial role in shaping both the commercialization path and the ultimate performance capabilities of SIBs. To overcome the intricate synthesis challenges associated with pure-phase sodium-ion cathode materials, this study introduces an innovative and streamlined electrochemical Li⁺/Na⁺ exchange process, successfully fabricating a high-capacity Ni-rich cathode material. This cathode material boasts a remarkable reversible capacity of 180 mAh g⁻¹ at 0.1 C and retains a high-rate capacity of 115 mAh g⁻¹ even at 5 C. Additionally, it exhibits exceptional cycling stability, retaining about 85% of its capacity at 1 C after 50 cycles and still maintaining a capacity greater than 60% after 100 cycles. The Na-NMA85 full cell preserves a discharge capacity of 110 mAh g⁻¹ after 100 cycles, with a capacity retention rate of 80%. This research underscores innovative strategies for designing ion-intercalation-based cathode materials that enhance battery performance, providing fresh perspectives for advancing high-performance battery technologies. Full article

One of the most interesting and poorly studied carriers of medicinal substances is the polymer clay composite material (PCCM). Bentonite clays are used in pharmacy for the manufacturing of various dosage forms, as well as in the adsorption of drugs to slow their release. Polymer–clay nanocomposites have demonstrated significantly improved properties compared to pure polymers. A review of recent scientific advances has shown promising results regarding the application of polymer–clay materials in medicine and bioengineering, particularly in the development of carrier sorbents with prolonged action for controlled drug release. As a result, interest in polymer–clay systems is steadily growing and gaining momentum. This paper focuses on the structure and properties of bentonite clays, including their sorption, ion exchange, binding, and rheological properties. The methods for preparing intercalated and exfoliated nanocomposites, such as radical intercalative polymerization in situ on clay surfaces, are reviewed. Furthermore, the improved efficacy and exposure times of PCCMs, combined with their enhanced bactericidal properties, are analyzed for the creation of universal and multifunctional preparations for medical use. Full article

Vanadium-based cathodes are promising for aqueous zinc-ion batteries (ZIBs) due to the large interlayer distance. However, the poor stability of electrode materials due to the dissolution effects has severely hindered the commercial development. To address this challenge, we propose an in situ NH₄⁺ pre-intercalation strategy to enhance the electrochemical performance of Na_0.76V₆O₁₅ (NaVO), thereby optimizing its structural stability and ionic conductivity. Moreover, NH₄⁺ pre-intercalation introduced a large number of oxygen vacancies and defects into the material, causing the reduction of V⁵⁺ to V⁴⁺. This transformation suppresses the dissolution and enhances its conductivity, thereby significantly improving the electrochemical performance. This modified NaNVO cathodes deliver a higher capacity of 456 mAh g⁻¹ at 0.1 A g⁻¹, with a capacity retention of 88% after 140 cycles and a long lifespan, maintaining 99% of its initial capacity after 2300 cycles. This work provided a new way to optimize the cathode for aqueous zinc-ion batteries. Full article

The development of high-performance electrochromic materials demands innovative approaches to simultaneously control the nanoscale architecture and the electronic structure. We present a dual-modification strategy that synergistically combines copper doping with the Langmuir–Blodgett (LB) assembly to overcome the traditional performance trade-offs in tungsten oxide-based electrochromic systems. Cu-doped W₁₈O₄₉ nanowires with varying Cu concentrations (0–12 mol%) were synthesized hydrothermally and assembled into thin films via the LB technique, with LB precursors characterized by contact angle, surface tension, viscosity, and thermogravimetric-differential scanning calorimetry (TG-DSC) analyses. The films were systematically evaluated using scanning electron microscopy, X-ray photoelectron spectroscopy, chronoamperometry, and transmittance spectroscopy. Experimental results reveal an optimal Cu-doping concentration of 8 mol%, achieving a near-infrared optical modulation amplitude of 76.24% at 1066 nm, rapid switching kinetics (coloring/bleaching: 5.0/3.0 s), and a coloration efficiency of 133.00 cm²/C. This performance is speculated to be a balance between Cu-induced improvements in ion intercalation kinetics and LB-ordering degradation caused by lattice strain and interfacial charge redistribution, while mitigating excessive doping effects such as structural deterioration and thermodynamic instability. The work establishes a dual-modification framework for designing high-performance electrochromic interfaces, emphasizing the critical role of surface chemistry and nanoscale assembly in advancing adaptive optoelectronic devices like smart windows. Full article

Na₂Ti₃O₇ (NTO), with low sodium insertion potential (~0.3 V vs. Na⁺/Na) and potential for high-energy-density batteries, is regarded as one of the most promising anode materials for sodium-ion batteries (SIBs). However, its practical application is hindered by poor electronic conductivity, sluggish Na⁺ (de)intercalation kinetics, and interfacial instability, leading to inferior cycling stability, low initial Coulombic efficiency, and poor rate capability. In this work, micron-sized rod-like NTO and Al-doped NTO (NTO-Al) samples were synthesized via a one-step high-temperature solid-state method. Al doping slightly reduced the size of NTO microrods while introducing oxygen vacancies and generating Ti³⁺, thereby enhancing electronic conductivity and reducing ionic diffusion resistance. H₂-TPR confirms that doping activates lattice oxygen and promotes its participation in the reaction. The optimized NTO-Al0.03 electrode delivered a significantly improved initial charge capacity of 147.4 mA h g⁻¹ at 0.5 C, surpassing pristine NTO (124.7 mA h g⁻¹). Moreover, it exhibited the best cycling stability (49.5% capacity retention after 100 cycles) and rate performance (36.3 mA h g⁻¹ at 2 C). Full article