Long-Term Autonomic Thermoregulating Fabrics Based on Microencapsulated Phase Change Materials.

Microcapsules loaded with n-docosane as phase change material (mPCMs) for thermal energy storage with a phase change transition temperature in the range of 36-45 °C have been employed to impregnate cotton fabrics. Fabrics impregnated with 8 wt % of mPCMs provided 11 °C of temperature buffering effect during heating. On the cooling step, impregnated fabrics demonstrated 6 °C temperature increase for over 100 cycles of switching on/off of the heating source.

Pencil Graphite Electrodes Decorated with Platinum Nanoparticles as Efficient Electrocatalysts for Hydrogen Evolution Reaction.

Platinum-based materials are widely known as the most utilized and advanced catalysts for hydrogen evolution reaction. For this reason, several studies have reported alternative methods of incorporating this metal into more economical electrodes with a carbon-based support material. Herein, we report on the performance of pencil graphite electrodes decorated with electrochemically deposited platinum nanoparticles as efficient electrocatalysts for hydrogen evolution reaction.

Chemical Modification of Chitosan for Removal of Pb(II) Ions from Aqueous Solutions.

Biomacromolecule have a significant contribution to the adsorption of metal ions. Moreover, chitosan is one of the most studied biomacromolecule, which has shown a good performance in the field of wastewater treatment. In this context, a new adsorbent of the aminophosphonic modified chitosan-supported Ni(II) ions type was prepared from the naturally biopolymer, chitosan.

Ordered Oxygen Vacancies in the Lithium-Rich Oxide LiCuSbO, a Triclinic Structure Type Derived from the Cubic Rocksalt Structure.

Li-rich rocksalt oxides are promising candidates as high-energy density cathode materials for next-generation Li-ion batteries because they present extremely diverse structures and compositions. Most reported materials in this family contain as many cations as anions, a characteristic of the ideal cubic closed-packed rocksalt composition. In this work, a new rocksalt-derived structure type is stabilized by selecting divalent Cu and pentavalent Sb cations to favor the formation of oxygen vacancies during synthesis.

LiAlSCl: A Sulfide-Chloride Lithium Ion Conductor with Highly Disordered Structure and Increased Conductivity.

Mixed anion materials and anion doping are very promising strategies to improve solid-state electrolyte properties by enabling an optimized balance between good electrochemical stability and high ionic conductivity. In this work, we present the discovery of a novel lithium aluminum sulfide-chloride phase, obtained by substitution of chloride for sulfur in LiAlS and LiAlS materials. The structure is strongly affected by the presence of chloride anions on the sulfur site, as the substitution was shown to be directly responsible for the stabilization of a higher symmetry phase presenting a large degree of cationic site disorder, as well as disordered octahedral lithium vacancies.

Chemical Control of the Dimensionality of the Octahedral Network of Solar Absorbers from the CuI-AgI-BiI Phase Space by Synthesis of 3D CuAgBiI.

A newly reported compound, CuAgBiI, is synthesized as powder, crystals, and thin films. The structure consists of a 3D octahedral Ag/Bi network as in spinel, but occupancy of the tetrahedral interstitials by Cu differs from those in spinel. The 3D octahedral network of CuAgBiI allows us to identify a relationship between octahedral site occupancy (composition) and octahedral motif (structure) across the whole CuI-AgI-BiI phase field, giving the ability to chemically control structural dimensionality.

Li Dynamics of Liquid Electrolytes Nanoconfined in Metal-Organic Frameworks.

Metal-organic frameworks (MOFs) are excellent platforms to design hybrid electrolytes for Li batteries with liquid-like transport and stability against lithium dendrites. We report on Li dynamics in quasi-solid electrolytes consisting in Mg-MOF-74 soaked with LiClO-propylene carbonate (PC) and LiClO-ethylene carbonate (EC)/dimethyl carbonate (DMC) solutions by combining studies of ion conductivity, nuclear magnetic resonance (NMR) characterization, and spin relaxometry. We investigate nanoconfinement of liquid inside MOFs to characterize the adsorption/solvation mechanism at the basis of Li migration in these materials.

Time-Resolved Raman Spectroscopy of Polaron Formation in a Polymer Photocatalyst.

Polymer photocatalysts are a synthetically diverse class of materials that can be used for the production of solar fuels such as H, but the underlying mechanisms by which they operate are poorly understood. Time-resolved vibrational spectroscopy provides a powerful structure-specific probe of photogenerated species. Here we report the use of time-resolved resonance Raman (TR) spectroscopy to study the formation of polaron pairs and electron polarons in one of the most active linear polymer photocatalysts for H production, poly(dibenzo[,]thiophene sulfone), P10.

Combined Role of Biaxial Strain and Nonstoichiometry for the Electronic, Magnetic, and Redox Properties of Lithiated Metal-Oxide Films: The LiMnO Case.

Understanding the interplay between strain and nonstoichiometry for the electronic, magnetic, and redox properties of LiMnO films is essential for their development as Li-ion battery (LIB) cathodes, photoelectrodes, and systems for sustainable spintronics applications as well as for emerging applications that combine these technologies. Here, density functional theory (DFT) simulations suggest that compressive strain increases the reduction drive of (111) LiMnO films by inducing >1 eV upshift of the valence band edge. The DFT results indicate that, regardless of the crystallographic orientation for the LiMnO film, biaxial expansion increases the magnetic moments of the Mn atoms.

Extended Condensed Ultraphosphate Frameworks with Monovalent Ions Combine Lithium Mobility with High Computed Electrochemical Stability.

Extended anionic frameworks based on condensation of polyhedral main group non-metal anions offer a wide range of structure types. Despite the widespread chemistry and earth abundance of phosphates and silicates, there are no reports of extended ultraphosphate anions with lithium. We describe the lithium ultraphosphates LiPO and LiPO based on extended layers and chains of phosphate, respectively.

A New Perspective on Adsorbent Materials Based Impregnated MgSiO with Crown Ethers for Palladium Recovery.

The study of new useful, efficient and selective structures for the palladium ions' recovery has led to the development of a new series of macromolecules. Thus, this study presents a comparative behavior of two crown benzene ethers that modify the magnesium silicate surface used as adsorbent for palladium. These crown ethers are dibenzo18-crown-6 (DB18C6) and dibenzo 30-crown-10 (DB30C10).

Sepiolite Nanocarriers as a Matrix for Controlled Thermal Energy Storage.

Applying the eutectic hydrated salt (EHS) mixture of NaHPO·12HO and NaSO·10HO in a 1:1 weight ratio as a phase-change material and natural sepiolite nanocarriers as a matrix, the form-stable phase-change composite EHS@sepiolite was fabricated by vacuum impregnation. Due to the high porosity of sepiolite and its nanofibrous structure with internal channels, the effective loading of the phase-change material reached as high as 88 wt %. The melting temperature of the composite was 38.

Identification of lead vacancy defects in lead halide perovskites.

Perovskite photovoltaics advance rapidly, but questions remain regarding point defects: while experiments have detected the presence of electrically active defects no experimentally confirmed microscopic identifications have been reported. Here we identify lead monovacancy (V) defects in MAPbI (MA = CHNH) using positron annihilation lifetime spectroscopy with the aid of density functional theory. Experiments on thin film and single crystal samples all exhibited dominant positron trapping to lead vacancy defects, and a minimum defect density of ~3 × 10 cm was determined.

Element selection for crystalline inorganic solid discovery guided by unsupervised machine learning of experimentally explored chemistry.

The selection of the elements to combine delimits the possible outcomes of synthetic chemistry because it determines the range of compositions and structures, and thus properties, that can arise. For example, in the solid state, the elemental components of a phase field will determine the likelihood of finding a new crystalline material. Researchers make these choices based on their understanding of chemical structure and bonding.

Polymorph of LiAlPO: Combined Computational, Synthetic, Crystallographic, and Ionic Conductivity Study.

We report a new polymorph of lithium aluminum pyrophosphate, LiAlPO, discovered through a computationally guided synthetic exploration of the Li-Mg-Al-P-O phase field. The new polymorph formed at 973 K, and the crystal structure, solved by single-crystal X-ray diffraction, adopts the orthorhombic space group with = 5.1140(9) Å, = 8.

Drug-Polymer Interactions in Acetaminophen/Hydroxypropylmethylcellulose Acetyl Succinate Amorphous Solid Dispersions Revealed by Multidimensional Multinuclear Solid-State NMR Spectroscopy.

The bioavailability of insoluble crystalline active pharmaceutical ingredients (APIs) can be enhanced by formulation as amorphous solid dispersions (ASDs). One of the key factors of ASD stabilization is the formation of drug-polymer interactions at the molecular level. Here, we used a range of multidimensional and multinuclear nuclear magnetic resonance (NMR) experiments to identify these interactions in amorphous acetaminophen (paracetamol)/hydroxypropylmethylcellulose acetyl succinate (HPMC-AS) ASDs at various drug loadings.

Interfacial Embedding of Laser-Manufactured Fluorinated Gold Clusters Enabling Stable Perovskite Solar Cells with Efficiency Over 24.

Tackling the interfacial loss in emerged perovskite-based solar cells (PSCs) to address synchronously the carrier dynamics and the environmental stability, has been of fundamental and viable importance, while technological hurdles remain in not only creating such interfacial mediator, but the subsequent interfacial embedding in the active layer. This article reports a strategy of interfacial embedding of hydrophobic fluorinated-gold-clusters (FGCs) for highly efficient and stable PSCs. The p-type semiconducting feature enables the FGC efficient interfacial mediator to improve the carrier dynamics by reducing the interfacial carrier transfer barrier and boosting the charge extraction at grain boundaries.

ZnO Films Incorporation Study on Macroporous Silicon Structure.

In the present work, we developed hybrid nanostructures based on ZnO films deposited on macroporous silicon substrates using the sol-gel spin coating and ultrasonic spray pyrolysis (USP) techniques. The changes in the growth of ZnO films on macroporous silicon were studied using a UV-visible spectrometer, an X-ray diffractometer (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). XRD analysis revealed the beneficial influence of macroporous silicon on the structural properties of ZnO films.

Electrochemical carbon dioxide reduction in ionic liquids at high pressure.

Imidazolium ionic liquids are potentially useful solvents for both carbon dioxide reduction conversion and capture. In particular electrocatalytic CO2 reduction has been shown to occur at low overpotentials using a 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][OTf]) and water mixed solvent. A limitation of such solvent systems is their viscosity, making it hard to maintain reasonable catalytic current densities without energy intensive stirring/agitation of the electrolyte.

Trapped interfacial redox introduces reversibility in the oxygen reduction reaction in a non-aqueous Ca electrolyte.

Electrochemical investigations of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have been conducted in a Ca-containing dimethyl sulfoxide electrolyte. While the ORR appears irreversible, the introduction of a tetrabutylammonium perchlorate (TBAClO) co-salt in excess concentrations results in the gradual appearance of a quasi-reversible OER process. Combining the results of systematic cyclic voltammetry investigations, the degree of reversibility depends on the ion pair competition between Ca and TBA cations to interact with generated superoxide (O ).

The unique carrier mobility of monolayer Janus MoSSe nanoribbons: a first-principles study.

Charge-carrier mobility is a determining factor of the transport properties of semiconductor materials and is strongly related to the optoelectronic performance of nanoscale devices. Here, we investigate the electronic properties and charge carrier mobility of monolayer Janus MoSSe nanoribbons by means of first-principles simulations coupled with deformation potential theory. These simulations indicate that zigzag nanoribbons are metallic.

Dynamics in Flexible Pillar[]arenes Probed by Solid-State NMR.

Pillar[]arenes are supramolecular assemblies that can perform a range of technologically important molecular separations which are enabled by their molecular flexibility. Here, we probe dynamical behavior by performing a range of variable-temperature solid-state NMR experiments on microcrystalline perethylated pillar[]arene ( = 5, 6) and the corresponding three pillar[6]arene xylene adducts in the 100-350 K range. This was achieved either by measuring site-selective motional averaged C H heteronuclear dipolar couplings and subsequently accessing order parameters or by determining H and C spin-lattice relaxation times and extracting correlation times based on dipolar and/or chemical shift anisotropy relaxation mechanisms.

Communicating assemblies of biomimetic nanocapsules.

Communication assemblies between biomimetic nanocapsules in a 3D closed system with self-regulating and self-organization functionalities were demonstrated for the first time. Two types of biomimetic nanocapsules, TiO2/polydopamine capsules and SiO2/polyelectrolytes capsules with different stimuli-responsive properties were prepared and leveraged to sense the external stimulus, transmit chemical signaling, and autonomic communication-controlled release of active cargos. The capsules have clear core-shell structures with average diameters of 30 nm and 25 nm, respectively.

Melting of hybrid organic-inorganic perovskites.

Several organic-inorganic hybrid materials from the metal-organic framework (MOF) family have been shown to form stable liquids at high temperatures. Quenching then results in the formation of melt-quenched MOF glasses that retain the three-dimensional coordination bonding of the crystalline phase. These hybrid glasses have intriguing properties and could find practical applications, yet the melt-quench phenomenon has so far remained limited to a few MOF structures.

Structure-property relationships on recrystallized β-cyclodextrin solvates: A focus on X-ray diffractometry, FTIR and thermal analyses.

The goal of the study was to evaluate the influence of the solvent properties on the crystal characteristics of β-cyclodextrin (β-CD) recrystallized from alcohol-water solvent mixtures, with possible applications for the preparation, purifying and complexation of β-CD. For the first time, structure-property relationships (QSPRs) between the hydrophobicity of alcohols or dielectric constant of solvents used for recrystallization of β-CD and its properties (such as crystallinity index, CI) have been obtained. Recrystallized β-CD from water and C-C alcohol-water solutions provide β-CD with higher CI values of 99.