Photochromic Sodalites: From Natural Minerals to Advanced Applied Materials.

ConspectusWhile photochromic natural sodalites, an aluminosilicate mineral, were originally considered as curiosities, articles published in the past ten years have radically changed this perspective. It has been proven that their artificial synthesis was easy and allowed compositional tuning. Combined with simulations, it has been shown that a wide range of photochromic properties were achievable for synthetic sodalites (color, activation energy, reversibility, etc.

Using pressure to unravel the structure-dynamic-disorder relationship in metal halide perovskites.

The exceptional optoelectronic properties of metal halide perovskites (MHPs) are presumed to arise, at least in part, from the peculiar interplay between the inorganic metal-halide sublattice and the atomic or molecular cations enclosed in the cage voids. The latter can exhibit a roto-translative dynamics, which is shown here to be at the origin of the structural behavior of MHPs as a function of temperature, pressure and composition. The application of high hydrostatic pressure allows for unraveling the nature of the interaction between both sublattices, characterized by the simultaneous action of hydrogen bonding and steric hindrance.

Photoelectrochemical Performance of Strontium Titanium Oxynitride Photo-Activated with Cobalt Phosphate Nanoparticles for Oxidation of Alkaline Water.

Photoelectrochemical (PEC) solar water splitting is favourable for transforming solar energy into sustainable hydrogen fuel using semiconductor electrodes. Perovskite-type oxynitrides are attractive photocatalysts for this application due to their visible light absorption features and stability. Herein, strontium titanium oxynitride (STON) containing anion vacancies of SrTi(O,N) was prepared via solid phase synthesis and assembled as a photoelectrode by electrophoretic deposition, and their morphological and optical properties and PEC performance for alkaline water oxidation are investigated.

Interfacial Engineering with a Nanoparticle-Decorated Porous Carbon Structure on β″-Alumina Solid-State Electrolytes for Molten Sodium Batteries.

We present a novel anode interface modification on the β″-alumina solid-state electrolyte that improves the wetting behavior of molten sodium in battery applications. Heat treating a simple slurry, composed only of water, acetone, carbon black, and lead acetate, formed a porous carbon network decorated with PbO (0 ≤ ≤ 2) nanoparticles between 10 and 50 nm. Extensive performance analysis, through impedance spectroscopy and symmetric cycling, shows a stable, low-resistance interface for close to 6000 cycles.

Recent Progress in Cathode Materials for Sodium-Metal Halide Batteries.

Transitioning from fossil fuels to renewable energy sources is a critical goal to address greenhouse gas emissions and climate change. Major improvements have made wind and solar power increasingly cost-competitive with fossil fuels. However, the inherent intermittency of renewable power sources motivates pairing these resources with energy storage.

Structure and electrochemical activity of nickel aluminium fluoride nanosheets during urea electro-oxidation in an alkaline solution.

An electrocatalyst of potassium nickel aluminium hexafluoride (KNiAlF) nanosheets has been prepared using solid-phase synthesis at 900 °C. X-ray diffraction, scanning electron microscopy, and conductivity studies confirmed the formation of KNiAlF nanosheets having a cubic defect pyrochlore structure with an average thickness of 60-70 nm and conductivity of 1.297 × 10 S m.

Highly Conductive Garnet-Type Electrolytes: Access to LiLaZrTaO Prepared by Molten Salt and Solid-State Methods.

Tantalum-doped garnet (LiLaZrTaO, LLZTO) is a promising candidate to act as a solid electrolyte in all-solid-state batteries owing to both its high Li conductivity and its relatively high robustness against the Li metal. Synthesizing LLZTO using conventional solid-state reaction (SSR) requires, however, high calcination temperature (>1000 °C) and long milling steps, thereby increasing the processing time. Here, we report on a facile synthesis route to prepare LLZTO using a molten salt method (MSS) at lower reaction temperatures and shorter durations (900 °C, 5 h).

Tissue paper-derived porous carbon encapsulated transition metal nanoparticles as advanced non-precious catalysts: Carbon-shell influence on the electrocatalytic behaviour.

Porous carbon encapsulated non-precious metal nanocatalysts have recently opened the ways towards the development of high-performance water remediation and energy conversion technologies. Herein, we report a facile, scalable and green synthetic methodology to fabricate porous carbon encapsulated transition metal nanocatalysts (M@TP: M = Cu, Ni, Fe and Co) using commercial tissue paper. The morphology, crystalline structure, chemical composition and textural properties of the M@TP nanocatalysts were thoroughly characterized.

Neuroanesthesia Guidelines for Optimizing Transcranial Motor Evoked Potential Neuromonitoring During Deformity and Complex Spinal Surgery: A Delphi Consensus Study.

Study Design: Expert opinion-modified Delphi study.

Objective: We used a modified Delphi approach to obtain consensus among leading spinal deformity surgeons and their neuroanesthesiology teams regarding optimal practices for obtaining reliable motor evoked potential (MEP) signals.

Summary Of Background Data: Intraoperative neurophysiological monitoring of transcranial MEPs provides the best method for assessing spinal cord integrity during complex spinal surgeries.

Nonaqueous Polymer Combustion Synthesis of Cubic LiLaZrO Nanopowders.

Garnet-type lithium lanthanum zirconate (LiLaZrO, LLZO) shows great promise as a solid electrolyte for future solid-state lithium batteries as it possesses a uniquely beneficial combination of high ionic conductivity, electrochemical stability against metallic lithium, and generally low reactivity in ambient conditions. Conventionally synthesized by using solid-state reactions, LLZO powders have also been prepared by using variations of sol-gel or combustion synthesis with sacrificial organic templates or polymers containing metal nitrate precursors. Herein, a novel nonaqueous polymer (NAP) method using metalorganic precursors and poly(vinylpyrrolidone) is demonstrated to easily form LLZO nanopowders.

Equal Footing of Thermal Expansion and Electron-Phonon Interaction in the Temperature Dependence of Lead Halide Perovskite Band Gaps.

Lead halide perovskites, which are causing a paradigm shift in photovoltaics, exhibit an atypical temperature dependence of the fundamental gap: it decreases in energy with decreasing temperature. Reports ascribe such a behavior to a strong electron-phonon renormalization of the gap, neglecting contributions from thermal expansion. However, high-pressure experiments performed on the archetypal perovskite MAPbI (MA stands for methylammonium) yield a negative pressure coefficient for the gap of the tetragonal room-temperature phase, which speaks against the assumption of negligible thermal expansion effects.

Experimental and Computational Study of the Lithiation of BaAl Ge Based Type I Germanium Clathrates.

In this work, we investigate the electrochemical properties of BaAl Ge ( y = 0, 4, 8, 12, 16) clathrates prepared by arc-melting. These materials have cage-like structures with large cavity volumes and can also have vacancies on the Ge framework sites, features which may be used to accommodate Li. Herein, a structural, electrochemical, and theoretical investigation is performed to explore these materials as anodes in Li-ion batteries, including analysis of the effect of the Al content and framework vacancies on the observed electrochemical properties.

Cognitive Aids for the Diagnosis and Treatment of Neuroanesthetic Emergencies: Consensus Guidelines on Behalf of the Society for Neuroscience in Anesthesiology and Critical Care (SNACC) Education Committee.

Cognitive aids and evidence-based checklists are frequently utilized in complex situations across many disciplines and sectors. The purpose of such aids is not simply to provide instruction so as to fulfill a task, but rather to ensure that all contingencies related to the emergency are considered and accounted for and that the task at hand is completed fully, despite possible distractions. Furthermore, utilization of a checklist enhances communication to all team members by allowing all stakeholders to know and understand exactly what is occurring, what has been accomplished, and what remains to be done.

Synthesis, structure and optoelectronic properties of hybrid iodobismuthate & iodoantimonate semiconducting materials.

The syntheses and structures of five iodobismuthate and nine iodoantimonate hybrid materials are presented. The 1,3-dimethyl-2-oxo-2,3-dihydropyrimidinium cation has been used to template the isostructural, one-dimensional [CHNO][SbI] (I) and [CHNO][BiI] (II), while 4-methylmorpholinium templates the compounds, [CHNO][SbI] (III) and [CHNO][BiI] (IV), both containing isolated iodopnictogenide cluster anions. Five iodoantimonate compounds, templated by piperazinium cation derivatives, have been synthesised; [CHN][SbI]·4HO (V), [CHN][SbI]·3HO (VI), two polymorphs of [CHN][SbI]·2HO (VII and VIII) and [CHN][SbI]·HO (IX), mainly adopting structures closely related to previously published 1D iodobismuthate hybrid materials.

Safety of a High-Dose Tranexamic Acid Protocol in Complex Adult Spinal Deformity: Analysis of 100 Consecutive Cases.

Study Design: Retrospective review of high-dose tranexamic acid (TXA) use in consecutive patients.

Objective: To determine the safety profile of a high-dose TXA protocol in complex adult spinal deformity patients.

Summary Of Background Data: Adult spinal deformity (ASD) surgery may involve significant amounts of blood loss, especially when various osteotomy techniques are used.

Zinc Tantalum Oxynitride (ZnTaO₂N) Photoanode Modified with Cobalt Phosphate Layers for the Photoelectrochemical Oxidation of Alkali Water.

Photoanodes fabricated by the electrophoretic deposition of a thermally prepared zinc tantalum oxynitride (ZnTaO₂N) catalyst onto indium tin oxide (ITO) substrates show photoactivation for the oxygen evolution reaction (OER) in alkaline solutions. The photoactivity of the OER is further boosted by the photodeposition of cobalt phosphate (CoPi) layers onto the surface of the ZnTaO₂N photoanodes. Structural, morphological, and photoelectrochemical (PEC) properties of the modified ZnTaO₂N photoanodes are studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet visible (UV-Vis) diffuse reflectance spectroscopy, and electrochemical techniques.

Anodes for Lithium-Ion Batteries Based on Type I Silicon Clathrate BaAlSi - Role of Processing on Surface Properties and Electrochemical Behavior.

Type I silicon clathrates based on BaAlSi (8 < y < 12) have been studied as potential anodes for lithium-ion batteries and display electrochemical properties that are distinct from those found in conventional silicon anodes. Processing steps such as ball-milling (typically used to reduce the particle size) and acid/base treatment (used to remove nonclathrate impurities) may modify the clathrate surface structure or introduce defects, which could affect the observed electrochemical properties. In this work, we perform a systematic investigation of BaAlSi clathrates with y ≈ 16, i.

Synthesis and structure of pseudo-three dimensional hybrid iodobismuthate semiconductors.

The synthesis, structures and semiconducting properties of three isostructural, piperazinium-cation based iodobismuthates, [NH(CH)NH][BiI]·4HO, [CHNH(CH)NH][BiI]·3HO and [CHNH(CH)HNCH][BiI]·2HO, are reported. The materials have pseudo-three dimensional structures consisting of infinite chains formed from edge/face sharing [BiI] octahedra with short interchain II interactions of <3.8 Å.

Dynamic disorder, phonon lifetimes, and the assignment of modes to the vibrational spectra of methylammonium lead halide perovskites.

We present Raman and terahertz absorbance spectra of methylammonium lead halide single crystals (MAPbX, X = I, Br, Cl) at temperatures between 80 and 370 K. These results show good agreement with density-functional-theory phonon calculations. Comparison of experimental spectra and calculated vibrational modes enables confident assignment of most of the vibrational features between 50 and 3500 cm.

Synthesis and structural characterisation of transition metal fluoride sulfates.

Eleven first row transition metal fluoride sulfates synthesised in hydrofluorothermal conditions have been structurally characterised by single crystal X-ray diffraction and exhibit a wide variety of structural motifs. The polyionic structures containing Ti, V, Mn and Fe vary from discrete polyhedral units in Na4TiF4(SO4)2 and [N2C10H12] TiF4SO4, through one dimensional chains in (K2FeF3SO4, Li3FeF2(SO4)2·H2O, Li1.87Ti1.

Structural diversity in hybrid organic-inorganic lead iodide materials.

The structural chemistry of hybrid organic-inorganic lead iodide materials has become of increasing significance for energy applications since the discovery and development of perovskite solar cells based on methylammonium lead iodide. Seven new hybrid lead iodide compounds have been synthesized and structurally characterized using single-crystal X-ray diffraction. The lead iodide units in materials templated with bipyridyl, 1,2-bis(4-pyridyl)ethane, 1,2-di(4-pyridyl)ethylene and imidazole adopt one-dimensional chain structures, while crystallization from solutions containing piperazinium cations generates a salt containing isolated [PbI6](4-) octahedral anions.

Experimental and theoretical optical properties of methylammonium lead halide perovskites.

The optical constants of methylammonium lead halide single crystals CH3NH3PbX3 (X = I, Br, Cl) are interpreted with high level ab initio calculations using the relativistic quasiparticle self-consistent GW approximation (QSGW). Good agreement between the optical constants derived from QSGW and those obtained from spectroscopic ellipsometry enables the assignment of the spectral features to their respective inter-band transitions. We show that the transition from the highest valence band (VB) to the lowest conduction band (CB) is responsible for almost all the optical response of MAPbI3 between 1.

Gallium fluoroarsenates.

Six new phases in the gallium-fluoride-arsenate system have been synthesised hydrofluorothermally using a fluoride-rich medium and "HAsF6" (HF : AsF5) as a reactant. RbGaF3(H2AsO4), KGaF(H2AsO4) and [piperazine-H2]2[Ga2F8(HAsO4)]·H2O have one dimensional structures, [DABCO-H2]2[Ga4F7O2H(AsO4)2]·4H2O consists of two dimensionally connected polyhedral layers, while GaF(AsO3[OH,F])2 and (NH4)3Ga4F9(AsO4)2 both have three-dimensionally connected polyhedral frameworks.