One Pot Synthesis of High Capacity Sulfur Cathodes via In Situ Polymerization of a Porous Imine Based Polymer

Lithium ion batteries, essential for electronics and electric vehicles, predominantly use cathodes made from critical materials like cobalt. Sulfur based cathodes, offering a high theoretical capacity of 1675 mAhg amp; 1048576; 1 and environmental advantages due to sulfur s abundance and lower toxicity, present a more sustainable alternative. However, state of the art sulfur based electrodes do not reach the theoretical capacities, mainly because conventional electrode production relies on mixing of components into weakly coordinated slurries. Consequently, sulfur s mobility leads to battery degradation an effect known as the sulfur shuttle . This study introduces a solution by developing a microporous, covalently bonded, imine based polymer network grown in situ around sulfur particles on the current collector. The polymer network i enables selective transport of electrolyte and Li ions through pores of defined size, and ii acts as a robust host to retain the active component of the electrode sulfur species . The resulting cathode has superior rate performance from 0.1 C 1360 mAhg amp; 1048576; 1 to 3 C 807 mAhg amp; 1048576; 1 . Demonstrating a high performance, sustainable sulfur cathode produced via a simple one pot process, our research underlines the potential of microporous polymers in addressing sulfur diffusion issues, paving the way for sulfur electrodes as viable alternatives to traditional metal based cathode

Advances in structure elucidation of small molecules using mass spectrometry

The structural elucidation of small molecules using mass spectrometry plays an important role in modern life sciences and bioanalytical approaches. This review covers different soft and hard ionization techniques and figures of merit for modern mass spectrometers, such as mass resolving power, mass accuracy, isotopic abundance accuracy, accurate mass multiple-stage MS(n) capability, as well as hybrid mass spectrometric and orthogonal chromatographic approaches. The latter part discusses mass spectral data handling strategies, which includes background and noise subtraction, adduct formation and detection, charge state determination, accurate mass measurements, elemental composition determinations, and complex data-dependent setups with ion maps and ion trees. The importance of mass spectral library search algorithms for tandem mass spectra and multiple-stage MS(n) mass spectra as well as mass spectral tree libraries that combine multiple-stage mass spectra are outlined. The successive chapter discusses mass spectral fragmentation pathways, biotransformation reactions and drug metabolism studies, the mass spectral simulation and generation of in silico mass spectra, expert systems for mass spectral interpretation, and the use of computational chemistry to explain gas-phase phenomena. A single chapter discusses data handling for hyphenated approaches including mass spectral deconvolution for clean mass spectra, cheminformatics approaches and structure retention relationships, and retention index predictions for gas and liquid chromatography. The last section reviews the current state of electronic data sharing of mass spectra and discusses the importance of software development for the advancement of structure elucidation of small molecules

Oxidation activity and <SUP>18</SUP>O-isotope exchange behavior of Cu-stabilized cubic zirconia

A series of Cu-ZrO2 samples with varying concentrations of Cu from 1 to 33 mol% have been prepared by sol-gel technique and calcined at 873 K. XRD characterization of the samples with a copper content of 2 to 20 mol% reveals the stabilization of zirconia into cubic (fluorite) phase. The Cu-ZrO2 samples with higher Cu content (&gt;20 mol%) revealed the presence of bulk CuO. A linear decrease in lattice parameter with increase in Cu content up to 20 mol% indicates the possible incorporation of Cu2+ in the lattice position of Zr4+ ions. XPS data of these samples provide further evidence for the incorporation of Cu2+ ions in the ZrO2 lattice up to 5 mol%. At higher concentrations of Cu, about half of the input of Cu goes into the lattice and the remaining stays as extra lattice Cu, possibly on the surface or subsurface layer of ZrO2. The BET surface area of these samples was in the range of 2 to 8 m2 g&#8722;1. The activity of these samples in CH4 and CO oxidation was investigated by 18O-isotope exchange as well as by catalytic reaction studies in complete oxidation of CH4 and CO. The Cu-ZrO2 with 20 mol% Cu was found to be the most active sample in the series, which has the maximum amount of copper in the substitutional position. For comparison, yttrium-stabilized zirconia samples with and without Cu was also prepared following the same procedure. Yttrium-stabilized zirconia without Cu was almost inactive in complete methane oxidation, whereas Cu-containing sample was more active. This confirms that the presence of Cu species in substitutional positions along with oxygen vacancies in zirconia lattice are substantially responsible for the catalytic activity in CH4 and CO oxidation as well as in complete heterogeneous 18O exchange processes. The light-off temperature for 50% conversion of CH4 (T50) decreases with an increase in Cu content up to 20 mol% and matches well with the results of 18O exchange measurements. The shapes of the curves of T50 and Texchange follow a similar trend indicating that both CH4 oxidation and 18O exchange processes occur via a completely heterogeneous mechanism

Porous MgF2 antireflective λ/4 films prepared by sol-gel processing: Comparison of synthesis approaches

Porous MgF2 is a highly promising film material for the preparation of durable antireflective coatings. Synthesis routes based on Mg(OMe)2 and Mg(OAc)2 precursors are described, and the resulting sol–gel films and their thermal consolidation are compared using thermal analysis (TGA/DTA), scanning electron microscopy, ellipsometric porosimetry and X-ray diffraction. Due to their constant viscosity, Mg(OAc)2-based coating solutions are superior from the practical point of view. The porous films are stable against degradation under the steady-state temperature humidity life test (85/85), and they can successfully be integrated into TiO2–MgF2–TiO2 interference filters

An Amorphous Teflate Doped Aluminium Chlorofluoride A Solid Lewis Superacid for the Dehydrofluorination of Fluoroalkanes

An anion doped aluminium chlorofluoride AlCl0.1F2.8 OTeF5 0.1 ACF teflate was synthesized. The material contains pentafluoroorthotellurate teflate groups, which mimic fluoride ions electronically, but are sterically more demanding. They are embedded into the amorphous structure. The latter was studied by PDF analysis, EXAFS data and MAS NMR spectroscopy. The mesoporous powder is a Lewis superacid, and ATR IR spectra of adsorbed CD3CN reveal a blue shift of the adsorption band by 73 amp; 8197;cm amp; 8722;1, which is larger than the shift for SbF5. Remarkably, ACF teflate catalyzes dehydrofluorination reactions of monofluoroalkanes to yield olefins in C6D6. In these cases, no Friedel Crafts products were forme