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Due to the increasing demand for lithium-ion batteries, there is an urgent requirement for environmentally friendly and efficient means of recycling these batteries. Graphite, a readily available and cost-effective material, tends to be neglected compared to more expensive metals such as cobalt or nickel. To achieve the new European targets, it will be necessary to focus on recycling even less valuable materials, such as graphite. Direct recycling of graphite represents an environmentally and economically viable solution. However, the capacity of recycled graphite depends on several factors, with pressing pressure being a potential variable. Within this article, we have focused on the impact of pressing pressure of spent graphite anode. The recycling was performed on the battery sample with a known lifetime history. It was found that when optimized, it is possible to achieve high stability and high capacities exceeding 300 mAh/g. [ABSTRACT FROM AUTHOR]

This work deals with the development of new anode materials for sodium-ion cells. Unlike lithium-ion batteries, where graphite is commonly used, it is not suitable for sodium-ion technology. Therefore, the aim is to identify an alternative material. Anthracite appears to be a promising candidate due to its affordability and geopolitical availability compared to graphite. The experimental part of the research involves the characterization of calcined anthracite, and its processing for the preparation of negative electrodes. This is followed by electrochemical characterization of the prepared electrodes. [ABSTRACT FROM AUTHOR]

In this letter, unique extra-long chemically derived pyramidal graphitic ribbons (PGR) were individualized and deposited onto a SiO2 substrate via simple spin-coating. The length of the individualized PGRs was found to exceed the average length of graphene nanoribbons (GNRs) by hundreds of microns. The physicochemical individualization method resulted in the creation of a novel "graphene nanoribbon intercalation compound" (GNRIC), following a strict stoichiometric relation between the GNR powder and alkali metals. Our experiments were conducted with the use of Na and K as intercalants at NaC8, KC8, and KC24 concentrations. Furthermore, we exposed them to THF and discovered that the nanoribbon bundles obtained from CVD bottom-up bulk synthesis of GNRs can be exfoliated. The exfoliated nanoribbons (ex-GNRs) were analyzed using SEM, Raman spectroscopy, optical microscopy, and AFM, revealing the existence of ribbon-like pyramidal nanostructures that are larger than 100 µm. The morphology of these graphitic ribbons, brings a new starting point and immense potential to the development of graphene-based devices for optoelectronics and solar cells. [ABSTRACT FROM AUTHOR]

The recent proliferation of renewable energy generation offers mankind hope, with regard to combatting global climate change. However, reaping the full benefits of these renewable energy sources requires the ability to store and distribute any renewable energy generated in a cost-effective, safe, and sustainable manner. As such, sodium-ion batteries (NIBs) have been touted as an attractive storage technology due to their elemental abundance, promising electrochemical performance and environmentally benign nature. Moreover, new developments in sodium battery materials have enabled the adoption of high-voltage and high-capacity cathodes free of rare earth elements such as Li, Co, Ni, offering pathways for low-cost NIBs that match their lithium counterparts in energy density while serving the needs for large-scale grid energy storage. In this essay, a range of battery chemistries are discussed alongside their respective battery properties while keeping metrics for grid storage in mind. Matters regarding materials and full cell cost, supply chain and environmental sustainability are discussed, with emphasis on the need to eliminate several elements (Li, Ni, Co) from NIBs. Future directions for research are also discussed, along with potential strategies to overcome obstacles in battery safety and sustainable recyclability.

This review is based on hydrothermal synthetic procedures that generate different vanadium oxide microstructures with mixed oxidation states, where different vanadium (V5+) precursors (vanadate, vanadium oxide, vanadium alkoxide, etc.,) are used to obtain various types of morphologies and shapes, such as sea urchins, cogs, stars, squares, etc., depending on the amphiphilic molecules (usually surfactants) exhibiting a structural director role containing an organic functional group such as primary amines and thiols, respectively. The performance of sol–gel methodology, where intercalation processes sometimes take place, is crucial prior to the hydrothermal treatment stage to control the V4+/V5+. In every synthesis, many physical and chemical parameters, such as temperature, pH, reaction time., etc., are responsible for influencing the reactions in order to obtain different products; the final material usually corresponds to a mixed oxidation state structure with different content rates. This feature has been used in many technological applications, and some researchers have enhanced it by functionalizing the products to enhance their electrochemical and magnetic properties. Although some results have been auspicious, there are a number of projects underway to improve the synthesis in many ways, including yield, secondary products, size distribution, oxidation state ratio, etc., to achieve the best benefits from these microstructures in the large number of technological, catalytic, and magnetic devices, among other applications.

The layered hexaniobate of K4Nb6O17 composition and its derivatives comprise nanostructured materials that exhibit suitable properties for application in catalysis, electrochemistry, and energy, for instance. The exchange of K+ cations to obtain the acidic or protonic niobate form is the main route to originate appropriate precursors to promote the hexaniobate exfoliation, yielding a dispersion of thin layers (2D particles) that can be scrolled under exclusive conditions. Hexaniobate presents two regions (I and II), being the former considered more accessible than region II. In this work, the proton exchange efficiency of the K4Nb6O17 was investigated by thermogravimetric analysis coupled to mass spectrometry (TGA-MS) and metal analysis by inductively coupled plasma spectroscopy (ICP). The products of thermal decomposition profile of the HxK(4-x)Nb6O17 phase were isolated at defined temperature values and characterized by X-ray diffractometry and Raman spectroscopy. The cation exchange percentages obtained by TGA-MS (68.0%) and by quantification of deintercalated K+ by ICP (64.0%) are similar and endorse that region II can also be modified and, consequently, contribute to the exfoliation process.

A single crystalline layered semiconductor In1.2Ga0.8S3 phase was grown, and by intercalating p-aminopyridine (NH2-C5H4N or p-AP) molecules into this crystal, a new intercalation compound, In1.2Ga0.8S3·0.5(NH2-C5H4N), was synthesized. Further, by substituting p-AP molecules with p-ethylenediamine (NH2-CH2-CH2-NH2 or p-EDA) in this intercalation compound, another new intercalated compound—In1.2Ga0.8S3·0.5(NH2-CH2-CH2-NH2) was synthesized. It was found that the single crystallinity of the initial In1.2Ga0.8S3 samples was retained after their intercalation despite a strong deterioration in quality. The thermal peculiarities of both the intercalation and deintercalation of the title crystal were determined. Furthermore, the unit cell parameters of the intercalation compounds were determined from X-ray diffraction data (XRD). It was found that increasing the c parameter corresponded to the dimension of the intercalated molecule. In addition to the intercalation phases' experimental characterization, the lattice dynamical properties and the electronic and bonding features of the stoichiometric GaInS3 were calculated using the Density Functional Theory within the Generalized Gradient Approximations (DFT-GGA). Nine Raman-active modes were observed and identified for this compound. The electronic gap was found to be an indirect one and the topological analysis of the electron density revealed that the interlayer bonding is rather weak, thus enabling the intercalation of organic molecules. [ABSTRACT FROM AUTHOR]

N–acetyl–L–cysteine (NAC), a derivative of the L–cysteine amino acid, presents antioxidant and mucolytic properties of pharmaceutical interest. This work reports the preparation of organic-inorganic nanophases aiming for the development of drug delivery systems based on NAC intercalation into layered double hydroxides (LDH) of zinc–aluminum (Zn2Al–NAC) and magnesium–aluminum (Mg2Al–NAC) compositions. A detailed characterization of the synthesized hybrid materials was performed, including X-ray diffraction (XRD) and pair distribution function (PDF) analysis, infrared and Raman spectroscopies, solid-state 13carbon and 27aluminum nuclear magnetic resonance (NMR), simultaneous thermogravimetric and differential scanning calorimetry coupled to mass spectrometry (TG/DSC–MS), scanning electron microscopy (SEM), and elemental chemical analysis to assess both chemical composition and structure of the samples. The experimental conditions allowed to isolate Zn2Al–NAC nanomaterial with good crystallinity and a loading capacity of 27.3 (m/m)%. On the other hand, NAC intercalation was not successful into Mg2Al–LDH, being oxidized instead. In vitro drug delivery kinetic studies were performed using cylindrical tablets of Zn2Al–NAC in a simulated physiological solution (extracellular matrix) to investigate the release profile. After 96 h, the tablet was analyzed by micro-Raman spectroscopy. NAC was replaced by anions such as hydrogen phosphate by a slow diffusion-controlled ion exchange process. Zn2Al–NAC fulfil basic requirements to be employed as a drug delivery system with a defined microscopic structure, appreciable loading capacity, and allowing a controlled release of NAC. [ABSTRACT FROM AUTHOR]

This review is based on hydrothermal synthetic procedures that generate different vanadium oxide microstructures with mixed oxidation states, where different vanadium (V5+) precursors (vanadate, vanadium oxide, vanadium alkoxide, etc.,) are used to obtain various types of morphologies and shapes, such as sea urchins, cogs, stars, squares, etc., depending on the amphiphilic molecules (usually surfactants) exhibiting a structural director role containing an organic functional group such as primary amines and thiols, respectively. The performance of sol–gel methodology, where intercalation processes sometimes take place, is crucial prior to the hydrothermal treatment stage to control the V4+/V5+. In every synthesis, many physical and chemical parameters, such as temperature, pH, reaction time., etc., are responsible for influencing the reactions in order to obtain different products; the final material usually corresponds to a mixed oxidation state structure with different content rates. This feature has been used in many technological applications, and some researchers have enhanced it by functionalizing the products to enhance their electrochemical and magnetic properties. Although some results have been auspicious, there are a number of projects underway to improve the synthesis in many ways, including yield, secondary products, size distribution, oxidation state ratio, etc., to achieve the best benefits from these microstructures in the large number of technological, catalytic, and magnetic devices, among other applications. [ABSTRACT FROM AUTHOR]

The development of biomaterials has a substantial role in pharmaceutical and medical strategies for the enhancement of life quality. This review work focused on versatile biomaterials based on nanocomposites comprising organic polymers and a class of layered inorganic nanoparticles, aiming for drug delivery (oral, transdermal, and ocular delivery) and tissue engineering (skin and bone therapies). Layered double hydroxides (LDHs) are 2D nanomaterials that can intercalate anionic bioactive species between the layers. The layers can hold metal cations that confer intrinsic biological activity to LDHs as well as biocompatibility. The intercalation of bioactive species between the layers allows the formation of drug delivery systems with elevated loading capacity and modified release profiles promoted by ion exchange and/or solubilization. The capacity of tissue integration, antigenicity, and stimulation of collagen formation, among other beneficial characteristics of LDH, have been observed by in vivo assays. The association between the properties of biocompatible polymers and LDH-drug nanohybrids produces multifunctional nanocomposites compatible with living matter. Such nanocomposites are stimuli-responsive, show appropriate mechanical properties, and can be prepared by creative methods that allow a fine-tuning of drug release. They are processed in the end form of films, beads, gels, monoliths etc., to reach orientated therapeutic applications. Several studies attest to the higher performance of polymer/LDH-drug nanocomposite compared to the LDH-drug hybrid or the free drug. [ABSTRACT FROM AUTHOR]

The uniaxial compound ZrTe 3 displays a complex charge density wave (CDW) ground state below ≈ 63 K. Here we report that Tb intercalated ZrTe 3 single crystals display superconductivity with T c ≈ 5.4 K. The effect of the Tb additions to the superconducting properties, magnetism, and CDW are probed by means of measurements of electrical resistivity (ρ), thermoelectric potential (S), and Hall effect. The temperature dependence of the upper critical field (H c2) could be fit with a two-band model. The magnetic susceptibility measurements suggest that upon the addition of Tb an antiferromagnetic order is developed with ordering temperature of T N ≈ 4.0 K. Tb doping's enhancing effect on T c suggests promising paths for future research involving lanthanide dopants in transition metal tellurides. • Enhancement of superconductivity to 5.4 K through terbium intercalation. • Experimental evidences show increased electronic correlations as the cause for T c enhancement. • The superconducting state shows resilience to the presence of magnetic impurities. • Terbium intercalation induces an antiferromagnetic order in the compound. [ABSTRACT FROM AUTHOR]

In the course of synthesis and studies of properties of nanomaterials based on layered molybdenum disulfide, it becomes necessary to perform rapid elemental analysis and to return the material to customer promptly. In some cases, to improve catalytic or magnetic properties, it is required to modify nanoparticles of molybdenum disulfide by metal compounds. A procedure is proposed for rapid X-ray fluorescence determination of molybdenum and cobalt in the content range of 10–50% in similar compounds by a bulk method without dilution. Analytical signals have been measured at the wavelengths of the MoKα and CoKα lines using a VRA-30 spectrometer (Carl Zeiss, Germany, X-ray tube with Rh anode). The content of the metals has been calculated using the derived equations of interrelations. The error of determination is ±2.7% (abs.) for Mo and ±1.4% (abs.) for Co. Correctness of the procedure has been confirmed for a batch of synthesized compounds by comparison with XRF results with dilution. This rapid method makes it possible to simplify the procedure and to reduce the time of analysis by more than 4 times; here, the sample is retained and can be used for further research. [ABSTRACT FROM AUTHOR]

Three types of lithium nickel–manganese–cobalt oxide (NMC) cathode materials (NMC532, NMC622, and NMC811) proposed for use in lithium-ion batteries were evaluated and compared by electrochemical methods. It was found how each transition metal (Ni, Mn, and Co) in this ternary compound affects the electrochemical performance of the cathode materials. Based on cyclic voltammetry, all three materials require pre-cycling to attain a suitable structure for electrochemical reactions. Ni and Co controlled the initial capacity of the materials, but capacity retention during cycling was determined by the stability of the material, which is balanced by the ratio adjusting of Ni, Mn, and Co. Mn and Co provide chemical stability and structural stability for NMC materials, respectively. The voltage decay in the NMC811 was less than the others due to the presence of higher amounts of Ni2+ and Ni3+, which have a much smaller radius than lithium-ion and less cation mixing. The capacity retention of NMC622 at high rates was higher than the other two materials. The combination of galvanostatic intermittent titration technique (GITT), cyclic voltammetry at different scan rates, and intercalation isotherm showed that the diffusion coefficient of lithium ion for NMC622 is higher than the other two materials. Electrochemical impedance spectroscopy showed that the resistance of the surface layer is lower in NMC622 than the others in different lithium-ion concentrations. The self-discharge test showed the superiority of NMC811 over the others. Considering all performance factors, NMC622 and NMC811 are efficient materials for various applications, especially electric vehicles. [ABSTRACT FROM AUTHOR]

• Polycrystalline compounds Ni x TiS 2 (0.10 ≤ x ≤ 0.50) were first synthesized. • The crystal structure of all the compounds is described in the P 3 ¯ m 1 space group. • Ni ions occupy only octahedral positions and are not ordered at any concentration. • Ni/S hybridization is more likely than usual Ni/Ti hybridization typical of LTMDs. Polycrystalline Ni x TiS 2 (0.10 ≤ x ≤ 0.50) compounds have been synthesized for the first time. The crystal structure and electrical properties of these compounds have been studied as a function of Ni concentration using X-ray diffraction and electromotive force (EMF) measurements of Li|Li+|Ni x TiS 2 electrochemical cells. It was found that the P 3 ¯ m 1 space group is characteristic for all compounds. The Ni ions occupy only octahedral positions in the interlayer space and are not ordered at any concentration. The Ni concentration does not alter the Fermi level of the compound due to the Ni 3 d z 2/Ti 3 d z 2 and Ni 3 d xz,yz /S 3 p hybridization. [ABSTRACT FROM AUTHOR]

Coumaric acid (CouH), an antioxidant molecule assimilated by food consumption, was intercalated into layered double hydroxide (LDH) nanocarrier, having zinc and aluminium ions in the layers (LDH-Cou), to evaluate its pharmacological activity through in vitro and in vivo assays in mice. Therefore, the following tests were performed: coumarate delivery in saline solution, fibroblasts' cell viability using neutral red, peritonitis induced by carrageenan, formalin test, acetic-acid-induced writhing, and tail-flick assay, for the non-intercalated CouH and the intercalated LDH-Cou system. Furthermore, different pharmacological pathways were also investigated to evaluate their possible anti-inflammatory and antinociceptive mechanisms of action, in comparison to traditionally used agents (morphine, naloxone, caffeine, and indomethacin). The LDH-Cou drug delivery system showed more pronounced anti-inflammatory effect than CouH but not more than that evoked by the classic non-steroidal anti-inflammatory drug (NSAID) indomethacin. For the analgesic effect, according to the tail-flick test, the treatment with LDH-Cou expressively increased the analgesia duration (p < 0.001) by approximately 1.7–1.8 times compared to CouH or indomethacin. Thus, the results pointed out that the LDH-Cou system induced in vivo analgesic and anti-inflammatory activities and possibly uses similar mechanisms to that observed for classic NSAIDs, such as indomethacin. [ABSTRACT FROM AUTHOR]

Auxins are a class of organic substances known as plant-growth regulators, which act on plant physiology, promoting its full development. However, due to the great instability of these substances among the diversity of crops and cultivation environments, it is necessary to seek more efficient modes of application, which lead to a homogeneous distribution and promote a sustained release according to the plants demand. Seed coating, using films containing a biodegradable polymer and auxins intercalated into layered compounds, emerges as a very promising approach to a new form of growth regulator application. Thus, the presented work had three aims: (i) the synthesis and characterization of an organic–inorganic hybrid material containing a layered double hydroxide (LDH) of zinc and aluminum and the synthetic auxin 1-naphthalenoacetic acid (ZnAl-NAA-LDH), (ii) the coating of bean seeds (Phaseolus vulgaris L.) with composite films produced from mixtures of alginate polymer and ZnAl-NAA-LDH, and (iii) the evaluation of the plant response by bioassays. The hybrid ZnAl-NAA-LDH was characterized by a set of analytical techniques, including powder X-ray diffraction, thermogravimetric analysis coupled to differential scanning calorimetry and mass spectrometry, specific surface area measurement, and scanning electron microscopy. Bioassays were performed with the seeds coated with the composite film to assess the germination rate and germination speed index of the seeds, as well as biometric analyses including measurements of root area, root fresh matter, and shoot length of the plants. The bioassay performed in soil pots showed that the alginate film containing ZnAl-NAA-LDH yields an enhancement regarding root area, fresh root matter and shoot length of plants. Thus, films produced from a mixture of alginate and the hybrid material containing the growth regulator intercalated into LDH can be a viable alternative to enhance plant development, which can be included in seed management.

In this work, Al cation was gradually replaced by FeIII in the composition of Layered Double Hydroxides (LDH) and systematically investigated for LDH application as drug carriers, ultimate aiming to improve their biointegration. The incorporation of FeIII into LDH layers, as well the intercalation of organic anions in the iron‐based materials, is challenging. Several studies approach the intercalation of non‐steroidal anti‐inflammatory drugs such as anionic naproxen (NAP) into Al‐LDH. Thus, NAP was applied here as a model drug for the study of compositional and structural aspects of novel FeIII‐LDH carriers envisaging to shed light on the intercalation of other carboxylate drugs into these materials. LDH of general [M2FeyAl(1‐y)(OH)6]An− compositions (MII=Mg or Zn; An−=anion of charge n) were investigated using two synthetic methods for NAP intercalation. Full X‐ray diffraction profile refinement and a crystal‐geometrical reasoning were used to strengthen the results interpretation. Unlike coprecipitation, in which probably NAP complexation with FeIII hinders LDH‐NAP self‐assembling, topotactic ion exchange demonstrated to be a potential approach. [ABSTRACT FROM AUTHOR]

Expansion of the works on the synthesis and study of the structure of new intercalation compounds based on molybdenum disulfide (MD) with various inclusions of organic molecules in the layered structures entails the necessity of developing methods for rapid analysis of those compounds for molybdenum content. We developed a rapid method of XRF analysis of such compounds using a bulk method in the range of 28–50% Mo content. Analytical signals were measured for the MoKα line on a VRA-30 spectrometer (Carl Zeiss, Jena, Germany; X-ray tube with Rh anode operated in the mode of 35 kV, 15 mA). The molybdenum content is calculated using the derived coupling equation; the error of determination is ±2.5% Mo (abs.). In contrast to the traditional methods of external standard with dilution used in laboratory practice, the proposed method provides satisfactory accuracy and reduces the duration of analysis from ~100 to ~20 min, the sample material being kept safe for further studies. Correctness of the method was confirmed for the batch of compounds by comparison of the obtained results and the data of XRF analysis with the dilution procedure. [ABSTRACT FROM AUTHOR]

The solid‐state synthesis of pure sodium‐black phosphorus intercalation compounds (Na‐BPICs) has been optimized in bulk for two stoichiometric ratios. Specifically, in‐situ X‐Ray diffraction (XRD) allowed the precise identification of the optimal temperature range for the formation of Na‐BPICs: 94 °C–96 °C. Moreover, as the undesired formation of Na3P takes place at this very same range, we succeeded in introducing a new synthetic route based on a fast‐thermal ball milling implementation that results in the bulk production of BPIC without Na3P in 9 out of 10 cases. Finally, by combining XRD, Raman spectroscopy, and DFT calculations we developed a new structural model for Na‐based BPICs showing an increase of BP's unit cell with Na atoms incorporated in every second layer. These results will pave the way for the large‐scale synthesis and application of pure BPICs, which are of great interest in fields such as optoelectronics or energy storage. [ABSTRACT FROM AUTHOR]

The study proposed a new formulation to the sustained delivery of mefenamate anions intercalated into Mg–Al layered double hydroxide (LDH) for oral administration. Different experimental conditions were evaluated to incorporate the mefenamic acid (MEF) and gum arabic (GUM) into LDH structure. The LDH–MEF and LDH–MEF/GUM were covered with chitosan (CHIT). In another experiment, LDH–Cl was used to adsorb mefenamate anions and evaluate the mechanism. The products of LDH were characterized by using different techniques such as FESEM (field emission scanning electron microscopy), XRD (X-ray diffraction), FTIR (Fourier transform infrared) spectroscopy and TGA (thermogravimetric analysis). The X-ray diffraction patterns and FTIR analyses confirmed that the MEF and GUM were successfully intercalated into the interlayer space of LDH. TG analysis verified that the thermal stability of intercalated MEF in the form of bionanocomposite (LDH–MEF/ /GUM/CHIT) was enhanced. Finally, In vitro drug release experiments of bionanocomposite at a pH of 1.2 (acidic medium) and a pH of 7.4 (phosphate buffer medium) showed sustained release profiles with mefenamate anions as an anti-inflammatory model drug.

Many lithium intercalation compounds, which have successful applications as lithium-ion battery electrode materials, are used not in individual state, but as a part of specially organized composites containing also auxiliary components distributed over the surface of intercalation-material particles, as well as in the interparticle space. The applied modifier-substances affect such characteristics of intercalation materials as capacity, its reversibility, and persistence during long-term cycling in the charge–discharge mode, as well as with varying the electrode current and potential ranges. In this work, the behavior of a modifying agent, belonging to the class of compounds known in the literature as MAX phases, is studied in detail in the composition of an electroactive composite. The MAX-phase agents have general formula Mn+ 1AXn, where M is the transition metal, A is the element of the Periodic Table III–VI groups, and X is C or N. The temperature required for the Ti3SiC2 compound synthesis is close to 1500°C. We succeeded in reducing the temperature by means of preliminary mechanochemical treatment of the reagents' mixture. The action mechanism of the Ti3SiC2-modifier is considered in comparison with similar models proposed in the literature. Comparison of the characteristics of composite materials with different Ti3SiC2-content and different types of modified intercalation compounds (substrates) showed a positive effect of the modifier both on the kinetics of electrode processes and the rate of degradation of the materials' capacitive characteristics. [ABSTRACT FROM AUTHOR]

Bismuthates with composition M3BiBr6 (M=Rb, Cs) form series of polymorphs capable of reversible H2O incorporation at room temperature. The host compounds were synthesized by annealing mixtures of MBr/BiBr3, or by precipitation from acidic solution and removing water molecules from the host framework of the hydrates in a thermal dehydration reaction. While the compound oP‐Rb3BiBr6 (space group Pbnm) is known from previous work, mP‐Rb3BiBr6 crystallizes with a new type of structure (space group P21/c). For Cs3BiBr6, the oP‐phase crystallizes isostructural to Cs3NdCl6 (space group Pbcm), the mC‐phase isostructural to Cs3BiCl6 (space group C2/c) and the tP‐phase isostructural to Tl3BiCl6 (space group P42/m). All crystal structures were refined from single crystal X‐ray diffraction data. In both systems, the crystal structures of orthorhombic and the monoclinic phases are polytypes and differ by stacking sequence only. By intercalation of water molecules, all polytypes of M3BiBr6 transform to semi‐hydrates M3BiBr6 ⋅ 1/2 H2O. Both, the incorporation of water and the reverse process proceed without the host structure being changed. The inclusion of crystal water was also confirmed by IR‐spectroscopy, thermal gravimetric analysis and mass spectrometry. The modification tP‐Cs3BiBr6 features a crystal structure with higher density and does not accommodate water. [ABSTRACT FROM AUTHOR]

Layered hybrid compounds (H3N(CH2)3NH3)[V4O10] and (H3N(CH2)4NH3)[V6O14] have been synthesized via the hydrothermal method. Compounds were analyzed through X-ray powder diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The electrochemical performance of electrode materials was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CV curves show only one electron transfer reaction, which is in accordance with insertion/extraction of the Li+ ion into/out from the material electrode. Furthermore, the kinetics of electrode reaction is controlled by charge transfer and diffusion processes. EIS measurements illustrate the lower charge transfer, which makes Li+ ion transfer quicker. In addition, values of lithium ion diffusion coefficient into these intercalation materials were found to be 0.1 × 10−10 and 0.21 × 10−11 cm2 s−1 for (H3N(CH2)3NH3)[V4O10] and (H3N(CH2)4NH3)[V6O14], respectively, after the 50th cycle. [ABSTRACT FROM AUTHOR]

The study proposed an approach for synthesis‐Layered Double Hydroxide nanoparticles by the coprecipitation method in solution containing two divalent and trivalent metal salts, calcium, and aluminum. The synthesized calcium‐layered Double Hydroxide (CAL) used for intercalating an anti‐inflammatory drug with the purpose of obtaining controlling release rate, protecting of drug from decomposition and raising the poor aqueous solubility of drug. Mefenamic acid (ME) as anti inflammatory drug was intercalated into CAL from ion‐exchange route to preparation CAL/ME nanohybrids. An increase in the space of interlayer of the (002) plane from 8.06 Å in pristine CAL to 34.51 Å in the nanohybrid confirmed successful intercalation of ME anion into CAL framework, which was ordered in a bilayer fashion with the carboxylate functional groups in the interlayer gallery of CAL. The x‐ray diffraction and FTIR study indicated that the ME was successfully intercalated into interlayer space of CAL. The chemical composition of samples was evaluated by ICP‐OES and energy‐dispersive spectrum analysis. TG analysis confirmed that the thermal stability of intercalated ME in the form of nanohybrid was enhanced. dynamic light scattering and field emission scanning electron microscopy were determined the size of CAL particles. Finally, in vitro drug release experiments of nanohybrid at a PH of 4.8 and 7.4 showed sustained release profiles with ME anions as an anti‐inflammatory model drug. [ABSTRACT FROM AUTHOR]

We present a linear stability analysis to demonstrate that a flat coherent phase boundary formed by the (de)intercalation of solutes into a compound is unstable against perturbations with wavelengths larger than a critical wavelength. This critical wavelength is controlled by the competition between the interface energy and the elastic strain energy caused by the misfit between the solute-rich and solute-poor phases. It increases with the distance between the phase boundary and free surface of the compound, and so the instability is most pronounced when the boundary is close to the surface at the early stage of the (de)intercalation process. Numerical calculations show that such instability leads to non-uniform intercalation behavior. We find that uniform intercalation cannot be achieved unless the phase boundary moves at a speed greater than a critical velocity. Estimate of the magnitude of this velocity suggests that the stress-induced intercalation instability is generally operative in intercalation compounds used for battery applications. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Introduction of ethylene diamine into the layers of graphene oxide was achieved through direct compounding method. Graphene oxide intercalated with ethylene diamine was characterised by Fourier transform‐infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), thermo gravimetric analysis (TGA) and scanning electron microscopy–energy dispersive X‐ray spectroscopy (SEM‐EDX) techniques. The efficiency of the material in adsorbing chromium was evaluated through batch scale studies by optimising parameters like pH, concentration and contact time. The material renders a monolayer adsorption capacity of 69.93 mg/g, at pH 1 within 60 min time period for a minimal dosage of 0.05 g. The ethylene diamine modified graphene oxide thus appeals to be a promising adsorbent for environmental applications. [ABSTRACT FROM AUTHOR]

The transition metal selenides M1+ySe2 (M = V, Ti) have intriguing quantum properties, which make them target materials for controlling properties by thinning them to the ultrathin limit. An appropriate approach for the synthesis of such ultrathin films is by molecular beam epitaxy. Here, it is shown that such synthesized V‐ and Ti‐Se2 films can undergo a compositional change by vacuum annealing. Combined scanning tunneling and photoemission spectroscopy is used to determine compositional and structural changes of ultrathin films as a function of annealing temperature. Loss of selenium from the film is accompanied by a morphology change of monolayer height islands to predominantly bilayer height. In addition, crystal periodicity and atomic structure changes are observed. These changes are consistent with a transition from a layered transition metal dichalcogenide (TMDC) to ordered intercalation compounds with V or Ti intercalated in between two layers of their respective TMDCs. These observations may clear up misconception of the nature of previously reported high‐temperature grown transition metal selenides. More significantly, the demonstrated control of the formation of intercalation compounds is a key step toward modifying properties in van der Waals systems and toward expanding material systems for van der Waals heterostructures. [ABSTRACT FROM AUTHOR]

Intercalation chemistry/engineering has been widely investigated in the development of electrochemical energy storage. Graphite, as an old intercalation host, is receiving vigorous attention again via a new halogen intercalation. Whereas, exploiting new intercalation hosts and optimizing the intercalation effect still remains a great challenge. This study fabricates a Cu2Se intercalation compound showing expanded interlayer space and nanosheet array features by using a green growth approach, in which cetyltrimethyl ammonium bromide (CTAB) is inserted into Cu2Se at an ambient temperature. When acting as an electrode material for sodium‐ion batteries, the Cu2Se–CTAB nanosheet arrays exhibit excellent discharge capacity and rate capability (426.0 mAh g−1 at 0.1 A g−1 and 238.1 mAh g−1 at 30 A g−1), as well as high capacity retention of ≈90% at 20 A g−1 after 6500 cycles. Benefiting from the porous array architecture, the transport of electrolytes is facilitated on the surface of Cu2Se nanosheets. In particular, the CTAB intercalated in the interlayer space of Cu2Se can increase its buffer space, stabilize the polyselenide shuttle, and prevent the fast growth of Cu nanoparticles during its electrochemical process. [ABSTRACT FROM AUTHOR]

The synthesized phases with chemical composition M 6 2 + Al 3 OH 18 A + SO 4 2 12 H 2 O (M2+ = Mn, Mg, Zn; A+ = Li, Na or K) were evaluated in relation to their thermal behavior by thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). In the shigaite (M2+ = Mn), natroglaucocerinite (M2+ = Zn) and motukoreaite (M2+ = Mg) phases, the TGA measurements indicated that all samples were dehydrated up to 200 °C in two steps, followed by dehydroxylation above 300 °C. After the thermal treatment at 1000 °C, formation of oxides/spinels were observed for the shigaite and natroglaucocerinite phases, while for motukoreaite, oxides, spinels and MgSO4 were detected. XRD indicated a reduction in the basal distance from around 11 Å for the fully hydrated phases to around 7 Å for the dehydrated phases. The thermal treatments of some samples at 100 °C, 150 °C and 200 °C indicated that in all phases, intercalated sulfate and alkaline metal ions can be dehydrated and rehydrated. As indicated by FTIR, at 200 °C sulfate could be grafted to the layers and at 300 °C, for all the phases, a stable mixture of amorphous materials was obtained, which could not be rehydrated. [ABSTRACT FROM AUTHOR]

In this work, signal integrity, power consumption and stability of multilayer vertical graphene nanoribbon (MLVGNR) interconnects are determined and compared with multilayer horizontal GNR (MLHGNR) and conventional copper interconnects for different intercalation dopants and specularity indices. Lithium‐intercalated MLVGNR outperforms these conventional interconnects in terms of delay. However, it is not very much immune to noise and also consumes more power but overall noise delay product and power delay product are least among all. As far as stability is concerned, MLVGNR interconnects have a comparable gain and phase margin and a steep transient response without an undershoot as compared with other interconnect configurations, which experience undershoot. It is worth to point out that MLVGNR interconnects are more amenable to scaling compared with other alternatives. This study for the first time analyses and compares the performance, signal integrity and stability of MLVGNR, MLHGNR and copper interconnects. [ABSTRACT FROM AUTHOR]

This contribution reports the preparation and study of a series of hybrid inorganic-organic solids obtained by intercalation of pyridine molecules between neighboring layers of 2D transition metal nitroprussides, T[Fe(CN)5NO]. The pyridine molecule coordinated to the axial positions for the metal (T) linked at the N ends of the equatorial CN ligands. From such regular pyridine molecule disposition at the layer and the attractive dispersive interactions and dipole-dipole coupling between neighboring molecules in the interlayer region, the formation of a long range 3D framework results. The refined crystal structure and the magnetic measurements shed light on the interaction between intercalated neighboring molecules. In the resulting 3D framework, the hybrid material preserves its 2D identity because no formation of chemical bonds is involved in the stacking process. Such structural features are properly supported by the refined crystal structures and computational studies for the interaction of the organic molecule with the metal (T) center. This series of hybrid solids crystallizes with an orthorhombic unit cell in the Ic2m space group. The unit cell volume shows a slight dependence of the metal (T), Ni < Co < Zn < Mn, which is related to the metal polarizing power and follows the order found for the T-NCN and T-NPy bond distances. The results herein discussed are relevant for hybrid inorganic-organic materials design, preparation and applications. [ABSTRACT FROM AUTHOR]

Intercalation compounds are popular candidate electrode materials for sodium-ion batteries and other 'beyond lithium-ion' technologies including potassium- and magnesium-ion batteries. We summarize first-principles efforts to elucidate the behaviour of such compounds in the layered and spinel structures. Trends based on the size and valence of the intercalant and the ionicity of the host are sufficient to explain phase stability and ordering phenomena, which in turn determine the equilibrium voltage profile. For the layered structures, we provide an overarching view of intercalant orderings in prismatic coordination based on antiphase boundaries, which has important consequences for diffusion. We examine details of stacking sequence transitions between different layered structures by calculating stacking fault energies and discussing the nature of dislocations. A better understanding of these transitions will likely aid the development of batteries with improved cyclability. This article is part of a discussion meeting issue 'Energy materials for a low carbon future'. [ABSTRACT FROM AUTHOR]

Abstract Anions from 2-aminoterephthalic acid (ATA), an aniline derivative, were intercalated into layered double hydroxide (LDH), and submitted to high-pressures by using a diamond anvil cell to access possible transformations of guest species in confined environment. The hybrid material, constituted by Ni2+ and Al3+ in a molar ratio equal to 2 (Ni 2 Al-ATA), was characterized by mass spectrometry coupled thermal analysis (TGA-DSC-MS), X-ray diffractometry (XRD) and vibrational spectroscopy (infrared and Raman) at ambient pressure. The response of Ni 2 Al-ATA to the pressure stimuli was monitored by in situ synchrotron XRD and in situ vibrational spectroscopies (infrared and Raman), during the compression-decompression cycle up to 14–16 GPa. XRD reflections related to (00 l) stacking planes of hybrid material presented broadening and intensities decreasing, pointing out a pressure-induced amorphization. XRD profile of Ni 2 Al-ATA was not recovered after decompression, indicating that the structural modification promoted by the pressure to the inorganic matrix is irreversible. In-situ vibrational spectroscopy as a function of pressure revealed a minor modification in the spectrum of ATA anion confined into LDH (for example, the Raman intensity decreasing (without shift) of the 1612 cm−1 band). Spectral features were recovered after the decompression, suggesting no decomposition or reactivity of the organic guest species between the LDH layers. On the other hand, Raman spectrum of 2-aminoterephthalic acid (non-intercalated) changed expressively during the decompression step and sample become completely luminescent at 1.7 GPa and at ambient pressure. Probably LDH decreases the guest reactivity by a steric blockage imposed by ATA arrangement in the confined environment, which can improve the guest stability submitted to high-pressure stimulus. Highlights • LDH-ATA material was submitted to high-pressures by using a diamond anvil cell. • Hybrid material undergoes an irreversible pressure-induced amorphization. • Intercalated organic species show no reactivity under pressure. • Raman spectrum of non-intercalated ATA changed expressively under pressure. • LDH improves the guest stability submitted to high-pressure stimulus. [ABSTRACT FROM AUTHOR]

Carboxymethylcellulose (CMC), a polymer derived from biomass, was intercalated into layered double hydroxides (LDH) composed byM2+/Al3+ (M2Al-CMC,M= Mg or Zn) and evaluated as precursors for the preparation of biocarbon-based nanocomposites by pyrolysis. M2Al-CMC hybrids were obtained by coprecipitation and characterized by X ray diffraction (XRD), vibrational spectroscopies, chemical analysis, and thermal analysis coupled to mass spectrometry. Following, pyrolyzed materials obtained between 500-1000 °C were characterized by XRD, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Above 600 °C, Raman spectra of all samples showed the presence of graphitic carbon, which plays a role in the degree of crystallinity of produced inorganic phases (for comparison purposes, M2Al-CO3 materials were investigated after calcination in the same experimental conditions). XRD patterns of Mg2Al-CMC pyrolyzed between 600-1000 °C showed poorly crystallized MgO and absence of spinel reflections, whereas for Zn2Al-CMC, it was observed well crystallized nanometric ZnO at 800 °C, and ZnAl2O4 and -Al2O3 phases at 1000 °C. Above 800 °C, the carbothermic reaction was noticed, transforming ZnO to zinc vapour. This study opens perspectives for nanocomposites preparation based on carbon and inorganic (mixed) oxides through precursors having organic-inorganic interactions at the nanoscale domain. [ABSTRACT FROM AUTHOR]

Abstract TiO 2 -B nanobelts have been synthesized by hydrothermal route using TiO 2 -anatase precursors with different microstructure. The decrease in average size of starting product improves the degree of TiO 2 -B crystallinity and increases the surface area. Both of them strongly influence on the electrochemical performance of as-prepared TiO 2 -B: the capacity of 203 mAh g−1 is still maintained after 35 cycles, with a degradation of 0.25% per cycle for material synthesized using TiO 2 -anatase phase with a particle size of 25 nm. Oppositely, the samples obtained from larger particles show poorer lithium storage with a worse capacity retention. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

A layered Zn-doped compound of Na0.7Zn0.15Mn0.75O2 is synthesized by a facile solid-state method. The product exhibits the same structure as P2-Na2/3Ni1/3Mn2/3O2, and some particles of the product are of lamellar shape with the thickness being about 0.6 μm. When the material is tested on the properties of intercalating/deintercalating Na+ in the voltage 2–4.4 V, it can deliver an initial discharge capacity of 158 mAh g−1. When the material is charged to different voltage, XPS spectra are performed on the surface of this material, and it is disclosed that oxygen activity makes the main part of contributions to charge compensation on the initial extracting Na+ process, while there is no apparent peak shift for the XPS spectra of Mn 2P3/2. [ABSTRACT FROM AUTHOR]

Abstract: The capacity retention of lithium intercalated cathode materials is strongly dependent on their surface condition, if surface is modified with various solid state compounds. In the present work one representative of carbosilicide type compounds known in literature as MAX-phase group (Mn+1AXn, where M is a transition metal, A is an element of III-VI group, and X is C and/or N) was used as surface modification agent. Synthesis temperature of Ti3SiC2 (TSC) compound, which is close to 1500 °C, was decreased by the application of special treatment of the reagents blend. The mechanism acting of TSC modification is presented and compared with other models, suggested in literature. Based on the results of experiments with different TSC contents and different substrate types we found positive effect of surface modification with TSC of the phosphate-based lithium intercalated cathode materials on their capacity fading rate. Outstanding high electronic conductivity of TSC makes this phase applicable as co-component in the composite electrode materials.Graphical abstract: [ABSTRACT FROM AUTHOR]

Graphical abstract Intercalation of Pyridine and its halogen derivatives between layers of Ni[Ni(CN) 4 ]. Between the octahedral Ni atoms, at low temperature, a ferromagnetic interaction is established mediated by the pi-pi stacking of neighboring aromatic pyridine rings. Highlights • Magnetic interaction mediated by pi-pi stacking. • Hybrid inorganic–organic solids. • Molecular magnets. • Intercalation of pyridine and its halogen derivatives in layered tetracyanonickelates. Abstract The intercalation of pyridine and its 3-substituted halogen derivatives (L) between layers of nickel (T) tetracyanonickelate provides a beautiful example of magnetic interaction through π-π stacking. The intercalation process results in the formation of 3D solids with formula unit TL 2 [Ni(CN) 4 ]. In the interlayer region, the intercalated molecules are found coordinated to the axial positions for the metal T (Ni). Neighboring molecules remain interacting through their dipole and quadrupole moments. For a coplanar configuration of their aromatic rings, the corresponding π-π clouds appear overlapped, which makes possible the appearance of a weak ferromagnetic interaction between T metal centers, to form an ordered system of magnetic chains separated about 10 Å. The halogen substituent in the pyridine molecule modulates the π-π clouds overlapping and, in consequence, the magnetic interaction through the chain. Such interaction coexists with a weak antiferromagnetic coupling between T atoms through the CN bridges in the two dimensional system, {T[Ni(CN) 4 ]} ∝ , but at low temperature, the interaction through the π-π clouds overlapping dominates. This contribution includes the study of the magnetic properties of the layered T(H 2 O) 2 [Ni(CN) 4 ]∙xH 2 O precursor solid where the magnetic interaction takes place through the hydrogen bonding network formed by the water molecules found in the interlayer region. The magnetic properties of both series of layered solids were evaluated from low temperature SQUID measurements complemented with structural and spectroscopic information. The interpretation of the magnetic and structural data is supported by computational calculations on the intermolecular interactions in the interlayer region. [ABSTRACT FROM AUTHOR]

Using a model tunnel manganese oxide with the todorokite crystal structure (T-MnO2), we demonstrate that controlling the morphology of the active material can improve the cycling stability of intercalation battery electrodes. The T-MnO2 structure is built from tunnels that provide spacious 1D diffusion channels for charge-carrying ions. Taking advantage of the unique ability to synthesize T-MnO2 in the form of both highly crystalline two-dimensional (2D) nanoplatelets and one-dimensional (1D) nanowires through a facile hydrothermal growth method, we investigated the effect of nanoscale particle dimensions on reversible battery cycling. Insertion of ions into the tunnels results in anisotropic expansion of the structure, making T-MnO2 with different morphologies an excellent model platform to understand how intercalation-induced volume change, typically leading to the deterioration of the electrode performance over extended cycling, can be controlled through synthesis of targeted morphologies. T-MnO2 nanowires showed not only significantly improved capacity retention but also substantially higher specific capacity than the T-MnO2 nanoplatelets. The enhanced electrochemical properties of the nanowire electrodes could be attributed to the larger surface-to-volume ratio than that of nanoplatelets, resulting in higher contact area with electrolyte for the nanowires. Moreover, due to the smaller cross-sectional area of the nanowires, volume expansion and contraction perpendicular to the structural tunnels induced by reversible ion intercalation occurs in a more facile fashion. This work shows that chemically controlling morphology and producing particles with nanostructure dimensionality replicating that of atomic structure (i.e., 1D morphology and 1D structure) makes it possible to enhance material performance.ᅟ [ABSTRACT FROM AUTHOR]

A novel proton conductor was synthesized by intercalation of phosphotungstic acid (PWA) into layered ferric sulfophenyl phosphate (FeSPP) via in-situ polymerization. Fe-O-W covalent bonds were formed between FeSPP and PWA in the synthesized intercalated proton conductor (FeSPP-PWA). FeSPP-PWA with a PWA content of up to 42 wt% remained the layered structure of FeSPP. FeSPP-PWA exhibited good thermal stability up to 200 °C. The ion-exchange capacity of FeSPP-PWA(15 wt%) was 1.73 meq g −1 . Its proton conductivity was 0.14, 6.6 × 10 −2 and 1.65 × 10 −2  S cm −1 at 100%, 50% and 0 RH at 180 °C, respectively, corresponding to the activation energy of 15.2, 17.3 and 27.0 kJ mol −1 , respectively. After washing for 12 and 24h, the conductivity of FeSPP-PWA(15 wt%) at 180 °C at 100% RH reduced by 1.5% and 1.7%, respectively. In comparison, the proton conductor prepared by direct mixing of FeSPP and PWA showed lower proton conductivity and poorer washing fastness than FeSPP-PWA. Intercalation of PWA into FeSPP proved to be an effective method for the preparation of high performance proton conductor. [ABSTRACT FROM AUTHOR]

This paper studies the crystal transition of graphite intercalation compounds during aluminum electrolysis. Transmission electron microscopy (TEM) analysis demonstrates that the transition induces the structural degradation of carbon cathodes. Buckling of basal planes in the hexagonal compounds contributes to the crystal transition of intercalation compounds from hexagonal to rhombohedral modification. First-principle techniques are used to calculate the structural and electronic properties of graphite intercalation compounds by density-functional theory using the plane wave Pseudo-potential method. The results have demonstrated a close relationship between lattice mismatch and intercalation compounds. The electronic band structure close to the Fermi level has been investigated. The main effect of intercalation compounds is to transfer charge from alkali metal s electron to the carbon p z orbitals, rendering the system metallic. With a decrease of band gap, the crystal transition induces an increase in the interlayer spacing and C–C bond lengths and deteriorates the structural stability of carbon cathodes. The overwhelming majority of contribution to the bands neighboring the Fermi level is from C pz orbital in both intercalation compounds. These findings provide new insights into the mechanisms of carbon cathodes deformation, damage and fracture behavior. • The crystal transition deteriorates the structural stability of carbon cathodes. • The intercalation compounds contribute to the metallic behavior of carbon cathodes. • The crystal defects facilitate the crystal transition of intercalation compounds. • The carbon p z orbitals play a role in the density of states at the Fermi energy. [ABSTRACT FROM AUTHOR]

Carboxymethylcellulose (CMC), a polymer derived from biomass, was intercalated into layered double hydroxides (LDH) composed by M2+/Al3+ (M2Al-CMC, M = Mg or Zn) and evaluated as precursors for the preparation of biocarbon-based nanocomposites by pyrolysis. M2Al-CMC hybrids were obtained by coprecipitation and characterized by X ray diffraction (XRD), vibrational spectroscopies, chemical analysis, and thermal analysis coupled to mass spectrometry. Following, pyrolyzed materials obtained between 500−1000 °C were characterized by XRD, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Above 600 °C, Raman spectra of all samples showed the presence of graphitic carbon, which plays a role in the degree of crystallinity of produced inorganic phases (for comparison purposes, M2Al-CO3 materials were investigated after calcination in the same experimental conditions). XRD patterns of Mg2Al-CMC pyrolyzed between 600−1000 °C showed poorly crystallized MgO and absence of spinel reflections, whereas for Zn2Al-CMC, it was observed well crystallized nanometric ZnO at 800 °C, and ZnAl2O4 and γ-Al2O3 phases at 1000 °C. Above 800 °C, the carbothermic reaction was noticed, transforming ZnO to zinc vapour. This study opens perspectives for nanocomposites preparation based on carbon and inorganic (mixed) oxides through precursors having organic-inorganic interactions at the nanoscale domain.