Optimizations of Liquid Phase Deposition Processes for Enhanced Photoelectrocatalytic Activities of Tungsten Oxide Thin Films.

This study focuses on the preparation of tungsten oxide (WO) as the photoanode for water oxidations by the liquid phase deposition (LPD) technique and its optimizations to improve the photoelectrochemical performance. The alternative precursor large stock solution process was achieved to simplify the LPD process for WO thin film preparation. The effect of boric acid in the precursor solutions on the physicochemical properties of the deposited WO thin films was investigated.

Kinetically Enhanced Reaction Pathway to Form Highly Crystalline Layered LiCoO at Low Temperatures Below 300 °C.

Layered LiCoO is usually synthesized after a prolonged sintering process at high temperatures (≥800 °C) for 10-20 h. This study developed a "hydroflux process" to obtain highly crystalline and layered LiCoO at a low temperature of 300 °C within 30 min. Molten mixed hydroxide-containing water molecules significantly accelerated the formation of LiCoO, which showed a highly reversible capacity of 120 mAh g without postannealing.

An experimental and first-principle investigation of the Ca-substitution effect on P3-type layered NaCoO.

We experimentally and computationally investigated the Ca substitution effect on the electrochemical performance of P3-NaxCoO2. The cycle performance of Ca-substituted NaxCa0.04CoO2 was effectively improved due to its better crystallinity retention after charging.

Destabilized Passivation Layer on Magnesium-Based Intermetallics as Potential Anode Active Materials for Magnesium Ion Batteries.

Passivation of magnesium metal anode is one of the critical challenges for the development of magnesium batteries. Here we investigated the passivation process of an intermetallic anode: MgBi synthesized by solid-state and thin film process. The MgBi composite electrode shows excellent reversibility in magnesium bis(trifluoromethansulfonylamide) dissolved in acetonitrile, while MgSb, which has same crystal structure and similar chemical properties, is electrochemically inactive.

In Situ Synthesis of a Supramolecular Hydrogelator at an Oil/Water Interface for Stabilization and Stimuli-Induced Fusion of Microdroplets.

Supramolecular hydrogels are expected to have applications as novel soft materials in various fields owing to their designable functional properties. Herein, we developed an in situ synthesis of supramolecular hydrogelators, which can trigger gelation of an aqueous solution without the need for temperature change. This was achieved by mixing two precursors, which induced the synthesis of a supramolecular gelator and its instantaneous self-assembly into nanofibers.

Quantitative NMR of quadrupolar nucleus as a novel analytical method: hydrolysis behaviour analysis of aluminum ion.

In this study, quantitative nuclear magnetic resonance (qNMR) spectroscopy of quadrupolar nuclei has been established. The complicated hydrolysis behavior of the Al ion, which causes fish poisoning and inhibits the growth of plants in environmental water, was clarified by Al qNMR spectroscopy. Highly accurate simultaneous multicomponent quantitative analysis of various hydrolyzed forms of the Al ion was achieved in a non-destructive manner.

Highly Conductive Ionic-Liquid Gels Prepared with Orthogonal Double Networks of a Low-Molecular-Weight Gelator and Cross-Linked Polymer.

We prepared a heterogeneous double-network (DN) ionogel containing a low-molecular-weight gelator network and a polymer network that can exhibit high ionic conductivity and high mechanical strength. An imidazolium-based ionic liquid was first gelated by the molecular self-assembly of a low-molecular-weight gelator (benzenetricarboxamide derivative), and methyl methacrylate was polymerized with a cross-linker to form a cross-linked poly(methyl methacrylate) (PMMA) network within the ionogel. Microscopic observation and calorimetric measurement revealed that the fibrous network of the low-molecular-weight gelator was maintained in the DN ionogel.

(15)N and (31)P NMR Insights into Lactam-Lactim Tautomerism Activity Using cyclo-μ-Imidopolyphosphates.

The effects of the molecular structure and solution pH on compounds prone to lactam-lactim tautomerism have been evaluated by (15)N NMR spectroscopy. The lactam-lactim tautomerism activities of cP3O6(NH)3(3-) and cP4O8(NH)4(4-) showed a significant pH dependence, with the process being inactivated under alkaline conditions because of the decrease in the number of hydrogen atoms by the deprotonation of the anions. The tautomerism was activated under the acidic conditions by the increase in the number of dissociative hydrogen atoms resulting from the protonation of the anions.

Nickel-Aluminum Layered Double Hydroxide Coating on the Surface of Conductive Substrates by Liquid Phase Deposition.

The direct synthesis of the adhered Ni-Al LDH thin film onto the surface of electrically conductive substrates by the liquid phase deposition (LPD) reaction is carried out for the development of the positive electrode. The complexation and solution equilibria of the dissolved species in the LPD reaction have been clarified by a theoretical approach, and the LPD reaction conditions for the Ni-Al LDH depositions are shown to be optimized by controlling the fluoride ion concentration and the pH of the LPD reaction solutions. The yields of metal oxides and hydroxides by the LPD method are very sensitive to the supersaturation state of the hydroxide in the reaction solution.

Room temperature direct imprinting of porous glass prepared from phase-separated glass.

This work describes a room-temperature imprinting of nanoporous glass prepared by selective chemical etching of phase-separated glass. A highly porous (58%) and highly transparent (>90%) porous glass layer can be formed on a transparent phase-separated glass substrate. It is shown that the lateral resolution of the imprinting is a few tens of nanometers.

⁹Be and ³¹P NMR analyses on the influence of imino groups on Be²⁺ complex stabilities of a series of cyclo-μ-imido triphosphate anions.

The complexation behaviors of Be²⁺ with cyclo-μ-imido triphosphate anions, cP₃O₉-n(NH)n(3-)n= 1, 2),have been investigated by both ⁹Be and ³¹P NMR techniques at -2.3 °C in order to clarify the coordination structures of the complexes. The spectra showed that cP₃O₉n(NH)n (n = 1, 2) ligands form ML, ML₂, and M₂L complexes with Be²⁺ ions, and the formation of complexes coordinating with nitrogen atoms of the cyclic framework in the ligand molecule has been excluded.

Synthesis, protonation equilibrium and peculiar thermal decomposition behavior of cyclo-tri-μ-imidotetraphosphate.

The synthesis and isolation of the sodium salt of cyclo-tri-μ-imidotetraphosphate, i.e. Na4cP4O9(NH)3·H2O, were achieved by the hydrolysis of Na4cP4O8(NH)4·2H2O under very weak acidic conditions, i.

Europium doping induced symmetry deviation and its impact on the second harmonic generation of doped ZnO nanowires.

In this work, we investigated the effects of europium doping on the second harmonic generation (SHG) of ZnO nanowires (NWs). A non-monotonic enhancement in the SHG is observed with the increase of the europium concentration. Maximum SHG is observed from the 1 at.

Supramolecular gelators based on benzenetricarboxamides for ionic liquids.

Supramolecular gelators comprising 1,3,5-benzenetricarboxylic acids and amino acid methyl esters (glycine, L-alanine, L-valine, L-leucine, L-methionine, and L-phenylalanine) for ionic liquids were developed. Ten types of ionic liquids were gelated using the above-mentioned gelators at relatively low concentrations. Field emission-scanning electron microscopy and confocal laser scanning microscopy analyses revealed that these gelators self-assembled into an entangled fibrous structure in ionic liquids, leading to the gelation of the ionic liquids.

Stabilities of the Divalent Metal Ion Complexes of a Short-Chain Polyphosphate Anion and Its Imino Derivative.

Abstract: The stability constants of ML-type complexes of the two linear triphosphate ligand anion analogues triphosphate ([Formula: see text]) and diimidotriphosphate ([Formula: see text]) were investigated thermodynamically using potentiometric titrations according to Schwarzenbach's procedure. The stability constants of the ML-type complexes of different divalent metal ions with [Formula: see text] are larger than those of the corresponding complexes with [Formula: see text] because of the greater basicity of the imino group. The order of the stability constants for the ML-type complexes follows the Irving-Williams order, indicating that only non-bridging oxygen atoms are coordinated directly to the different metal ions in both ligands, and that the imino groups cannot participate in coordination to the metal ions.

Terahertz wire grid polarizer fabricated by imprinting porous silicon.

A terahertz (THz) wire-grid polarizer is fabricated by imprinting porous Si followed by oblique evaporation of Ag. We demonstrate that it works in a wide frequency region covering from 5 to 18 THz with the extinction ratio of 10 dB. The frequency region is much wider than that of THz wire-grid polarizers fabricated by conventional imprint lithography using organic materials.

Versatile supramolecular gelators that can harden water, organic solvents and ionic liquids.

We developed novel supramolecular gelators with simple molecular structures that could harden a broad range of solvents: aqueous solutions of a wide pH range, organic solvents, edible oil, biodiesel, and ionic liquids at gelation concentrations of 0.1-2 wt %. The supramolecular gelators were composed of a long hydrophobic tail, amino acids and gluconic acid, which were prepared by liquid-phase synthesis.

Discrimination of transparent polyethylene films based on identification of inorganic antiblocking agents.

Several nondestructive and semidestructive analyses were used to discriminate colorless transparent polyethylene bags. Transparent plastic bags made from low-density and linear low-density polyethylene usually contain antiblocking agents to prevent sticking of the film, which makes it difficult to open the mouths of plastic bags. Inorganic antiblocking agents are uniformly dispersed in polyethylene films, so they are easily observed using optical microscopy.

Efficient near-infrared emission from neodymium by broadband sensitization of bismuth in zeolites.

Nd-Bi codoped zeolites were prepared by an ion-exchange process, and the optical properties were investigated by photoluminescence (PL) and PL excitation spectra, and decay time measurements. The results show that the NIR emission of Nd(3+) ions is significantly enhanced by the introduction of bismuth in codoped samples, and the lifetime reaches 246 μs. It is also observed that NIR-active Bi acts as a sensitizer of Nd(3+) ions.

Evaluation of nucleic acid duplex formation on gold over layers in biosensor fabricated using Czochralski-grown single-crystal silicon substrate.

With a view to developing an economical and elegant biosensor chip, we compared the efficiencies of biosensors that use gold-coated single-crystal silicon and amorphous glass substrates. The reflectivity of light over a wide range of wavelengths was higher from gold layer coated single-crystal silicon substrates than from glass substrates. Furthermore, the efficiency of reflection from gold layers of two different thicknesses was examined.

Efficient near-infrared luminescence and energy transfer in erbium/bismuth codoped zeolites.

We have shown that tunable and highly efficient broadband near-IR (NIR) luminescence can be realized in erbium/bismuth codoped zeolites. The emission covers the ranges of 930-1450nm and 1450-1630nm. The intensity ratio of the two bands can be tuned by adjusting the concentration of erbium and the excitation wavelength.

Controlled synthesis and luminescent properties of erbium silicate nanostructures.

Erbium silicate (Er2SiO5 and Er4Si3O12) nanostructures were successfully synthesized by a facile molten-salt approach in the presence of NaCI and surfactant. The synthesized products were structurally and morphologically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM), whereas the luminescent properties were characterized by temperature-dependent luminescence measurements. The results revealed that the composition, crystalline phase, and yield of the final products can be readily controlled by choosing suitable surfactant and tailoring the molar ratio of reactants used for the reactions.

One-step synthesis and near-infrared luminescent properties of Er3+ and Ni2+ doped single-crystalline Al18B4O33 nanorods.

Er(3+) and Ni(2+) doped single-crystalline Al(18)B(4)O(33) nanorods were synthesized by a facile one-step toxic-free combustion method. The products were characterized by x-ray diffraction, transmission electron microscopy, selected area electron diffraction, and integrated and time-resolved photoluminescence (PL) measurements. The phase purity, morphology, and PL properties of Er(3+) and Ni(2+) doped Al(18)B(4)O(33) nanorods can be readily controlled by tailoring the annealing temperature.

Superbroadband near-IR nano-optical source based on bismuth-doped high-silica nanocrystalline zeolites.

We have shown that efficient superbroadband near-IR luminescence can be realized in bismuth-doped high-silica nanocrystalline zeolites. The emission band covered the range of 930-1620 nm, with a maximum peak at 1146.3 nm, an FWHM of 152 nm, and a lifetime of over 300 mus under the excitation of a 488 nm laser line.