The effect of the synthesis temperature on chemical composition "Li1.20Mn0.54Co0.13Ni0.13O2" was considered using thermogravimetric analyses (TGA) and in situ X-ray diffraction (XRD) during thermal treatment. A continuous small weight loss is observed above 800 °C because Li evaporation, lamellar phase disappears to benefit a spinel-type formed 940 °C. layered structure recovered upon cooling under air. materials synthesized at 800, 900, 1000 show very similar compositions, structures,...

In this work, we investigate the crystal chemistry of Fe/V-mixed NASICON [sodium (Na) Super Ionic CONductor] compositions Na3FeV(PO4)3 and Na4FeV(PO4)3 that are structurally related to Na3V2(PO4)3, a positive electrode for Na-ion batteries. To synthesize Na4FeV(PO4)3, various synthesis routes (solid-state, sol–gel-assisted, electrochemical syntheses) were investigated. Direct syntheses resulted in formation NASICON-type phase presence NaFePO4 Na3PO4 impurities. The successful preparation...

Vanadium multi redox reactions of V4+/3+ and V5+/4+ can contribute to significant capacity gain in positive electrodes for Na-Ion batteries, but the activation couple is often accompanied by asymmetric irreversible electrochemical that are very important understand developing high materials while maintaining structural stability. Here, Na+ extraction/insertion process Fe/V-mixed NASICON Na4FeV(PO4)3 electrode material thoroughly investigated from both local bulk perspectives. X-ray...

Interactions between water and ferrous rocks are known to generate natural H 2 in oceanic continental domains via the oxidation of iron. Such generation has been mainly investigated through alteration Fe 2+ -silicate some -carbonates. So far, magnetite ( α -Fe 3 O 4 ) never considered as a potential source mineral for since it is by-product every chemical reaction leading formation , despite bears 1/3 its lattice. This iron oxide rather seen good catalyst . Recently, hydrogen emissions were...

The diaspore-type crystalline structure is historically well-known in mineralogy, but it has also been widely studied for various applications the field of catalysis, electrocatalysis, and batteries. However, once two anions similar ionic size different electronegativity, such as F- O2- or more precisely OH-, are combined, knowledge location these paramount importance to understand chemical properties relation with generation hydrogen bonds. Coprecipitation hydrothermal routes were used...

Doping is generally used to tune and enhance the properties of metal oxides. However, their chemical composition cannot be readily modified beyond low dopant amounts without disrupting crystalline atomic structure. In case anatase TiO2, we introduce a new solution-based route allowing significantly modified, substituting divalent O2– anions by monovalent F– OH– resulting in formation cationic Ti4+ vacancies (□) whose concentration can controlled reaction temperature. The polyanionic has...

Mn-doped ZnAl₂O₄ can show a red to green luminescence switch with thermal treatment and is potential candidate for sensing pigments.

Sodium-rich iron hexacyanoferrates were prepared by coprecipitation, hydrothermal route, and under reflux, with or without dehydration. They obtained different structures described in cubic, orthorhombic, rhombohedral symmetry, variable compositions sodium, water, cationic vacancies a variety of morphologies. This series sodium-rich Prussian blue analogues allowed addressing the relationship between synthesis conditions, composition, structure, morphology, electrochemical properties Na-ion...

We report the synthesis of WO3, TiO2, and TiO2–WO3 nanoparticles by a polyol route, with objective studying influence preparation method on their photochromic properties. By combining transmission electron microscopy, X-ray diffraction, photoelectron spectroscopy, diffuse reflectance experiments, we show that low W6+ concentrations high ripening temperatures allow WO3 efficiency. WO3–TiO2 nanocomposites (NCs) prepared introduction TiO2+ solution in nanoparticle suspension exhibit strong...

The thermosalient effect is still a rare and poorly understood phenomenon, where crystals suddenly jump, bend, twist or explode upon undergoing thermally activated phase transition. synthesis characterisation of the new spin transition Fe(iii) compound [Fe(5-Br-salEen)2][ClO4] (salEen = N-ethyl-N-(2-aminoethyl)salicylaldiminate) described its behaviour reported. It first example with magnetic, calorimetric, diffraction, microscopy computational studies are used to characterise these effects....

Abstract F‐doped La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3‐x− δ F x (LSCFF , = 0.05, 0.10, and 0.20) materials are evaluated as oxygen electrodes for solid oxide fuel electrolyser cell application. Materials have been prepared via low‐temperature topotactic route by fluorination of the parent with polyvinylidene fluorine (PVDF). A decrease in polarisation resistance ( R p ) is observed “LSCFF ” symmetric cells. However, improved electrochemical behavior cells cannot be explained presence fluorine,...

LiCoPO4 and LiNiPO4 phosphate pigments have colorations very close to the primary colors of subtractive system: magenta yellow, respectively. These two are therefore great interest in a variety applications, including e-reader devices. However, need reduce their crystallite size order formulate stable electrophoretic inks has revealed that aggressive milling results significant color changes, particularly for cobalt-based pigments. Here, we elucidate origin this phenomenon by carefully...

Identifying and characterizing defects in crystalline solids is a challenging problem, particularly for lithium-ion intercalation materials, which often exhibit multiple stable oxidation spin states as well local ordering of lithium charges. Here, we reveal the existence characteristic defect environments battery electrode LiVPO4F establish relative subnanometer-scale proximities between them. Well-crystallized samples were synthesized with expected tavorite-like structure, established by...

Microwave-assisted synthesis allows stabilizing Fe-based fluoride compounds with hexagonal tungsten bronze (HTB) network. The determination of the chemical composition, i.e., FeF2.2(OH)0.8·(H2O)0.33, revealed a significant deviation from pure high content OH groups substituting ions. Rietveld refinement X-ray diffraction data and Mössbauer spectroscopy showed that partial OH/F substitution impact on structure (interatomic distances, angles, so on) local environment iron (isomer shift...

Because of a very low thermodynamic stability, obtaining pure monophasic compound ferric pseudobrookite is quite difficult to achieve. Indeed, the reticular energy this phase leads easily its decomposition and occurrence secondary phases: hematite (Fe2O3) and/or rutile (TiO2). Samples with global composition Fe2-xTi1+xO5 (x = 0, 0.05, 0.10) have been synthesized by Pechini route and, thereafter, thermally treated at different temperatures. The concentrations Fe2O3 TiO2 phases were accurately...

The comparative structural, Mössbauer, and electrochemical studies of the NaxMn2/3Fe1/3O2 NaxMn1/2Fe1/2O2 systems show that change in Mn/Fe ratio has a significant influence on overlap between Mn3+/4+ Fe3+/4+ redox couples. P2-type structure is maintained 0.3 < x 0.8 domain. For highest intercalation amount, structural distortions occur due to Jahn–Teller effect Mn3+ ions. macroscopic distortion results from competition opposite effects Fe3+: isotropic character Fe3+ tends prevent...

Tungsten trioxide (WO3) is well-known as one of the most promising chromogenic compounds. It has a drastic change coloration induced from different external stimuli and so its applications are developed gas sensors, electrochromic panels or photochromic sensors. This paper focuses on properties nanoWO3, with tunable composition (with oxygen sub-stoichiometry). Three reference samples yellow, blue black colors were prepared polyol synthesis followed by post annealing under air, none...

We here present the synthesis of a new material, Na3(VO)Fe(PO4)2F2, by sol–gel method. Its atomic and electronic structural descriptions are determined combination several diffraction spectroscopy techniques such as synchrotron X-ray powder absorption at V Fe K edges, 57Fe Mössbauer, 31P solid-state nuclear magnetic resonance spectroscopy. The crystal structure this newly obtained phase is similar to that Na3(VO)2(PO4)2F, with random distribution Fe3+ ions over vanadium sites. Even though...

Silicate-based bioactive glass nano/microspheres hold significant promise for bone substitution by facilitating osteointegration through the release of biologically active ions and formation a biomimetic apatite layer. Cu-doping enhances properties such as pro-angiogenic antibacterial behavior. While sol-gel methods usually yield homogeneous spherical particles pure silica or binary glasses, synthesizing poorly aggregated Cu-doped ternary nano/microparticles without secondary CuO crystalline...

Abstract The energy efficiency of smart windows can be greatly improved by integrating dual‐band electrochromic materials based on nanostructured doped metal oxides, as these allow for the dynamic and independent control light heat supplies in buildings, respectively, related to transmitted visible (VIS) near‐infrared (NIR) solar radiations. Mixed molybdenum–tungsten oxides Mo y W 1− O 3− δ “MoWOx” are considered innovative compounds this context: comparison with parent WO formulations, a...