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Silicon oxide-coated lithium aluminum layered double hydroxide (Lix Al2 -LDH@SiO2 ) nanocrystals (NCs) are investigated to selectively separate lithium cations in aqueous lithium resources. We directly synthesized Lix Al2 -LDH NC arrays by oxidation of aluminum foil substrate under a urea and lithium solution. Various lithium salts, including Cl- , CO32- , NO3- , and SO42- , were applied in aqueous solution to confirm the anion effect on the captured and released lithium quantity of the Lix Al2 -LDH NCs. In a 5% solution of sulfate ions mix with lithium chloride, the Lix Al2 -LDH NCs separated a larger quantity of lithium than in other anion conditions. To enhance regeneration stability and lithium selectivity, thin layers of SiO2 were coated onto the Lix Al2 -LDH nanostructure arrays for inhibition of nanostructure destruction after desorption of lithium cations in hot water. The Lix Al2 -LDH@SiO2 nanostructures showed enhanced properties for lithium adsorption, including increase of stable regeneration cycles from three to five cycles, and they showed high lithium selectivity in the Mg2+ , Na+ , and K+ cation mixed aqueous resource. Our nanostructured LDH lithium adsorbents would provide a facile and efficient application for cost-efficient and large-scale lithium production.

Organic polymers can enhance the environmental stability of inorganic perovskite nanocrystals (IPNCs) by encapsulation. We fabricated lead-free IPNCs embedded in waterproof and luminous polymer fibers. The encapsulated CsCu2I3 and Cs3Cu2I5 nanocrystals within polystyrene (PS) polymers, CsCu2I3@PS (Y-fiber) and Cs3Cu2I5@PS (B-fiber) were prepared by one-step electrospinning of the precursor solutions containing the precursors (CsI and CuI) and PS. The embedded nanocrystals had highly uniform sizes, spatial distribution, well-developed crystal structure, and pure phases. The Y-fibers and B-fibers showed bright yellow and blue color emission under ultraviolet (UV) light, respectively, and a white emission fiber layer was fabricated via dual-nozzle co-electrospinning using yellow-emissive CsCu2I3, and blue-emissive Cs3Cu2I5 precursor solutions. The as-prepared B-fibers exhibited improved water stability without changing crystal structure and PL emission in deionized water for 20 days. To enhance environmental stability and mechanical properties, the transparent polydimethylsiloxane (PDMS) films containing IPNCs@PS fibers presented strong PL emission without a shift in PL emission wavelength under 100% tensile strain, indicating highly flexible and humidity-durable characteristics.

In this study, core–shell-structured Fe3O4@SiO2 nanoparticles were synthesized using sodium silicate (Na2SiO3), which is more suitable for mass production than the conventional silane precursor tetraethyl orthosilicate (TEOS). In the particle-surface coating process to form a core–shell structure with Fe3O4, the Na2SiO3 was neutralized with HCl(aq) to form silane groups, and the resulting silane groups combined with hydroxyl groups (OH−) present on the surfaces of the Fe3O4 nanoparticles. Because of the core–shell nanostructure of the single particles, the Fe3O4 nanoparticles were accompanied by significant changes in their intrinsic physicochemical properties. In addition, it was confirmed that there were differences in the thickness of the SiO2 under different neutralized pH conditions for the coating-layer implementation with Na2SiO3. The behavior of the Fe3O4 nanoparticle characteristics with respect to the SiO2 coating-layer thickness was primarily due to changes in the surface properties, associated with the degree of cathodic increase of the surface charge. An intensified negative surface charge enhanced the dispersibility of the particles in aqueous solution with enhanced electrostatic repulsion, which was even higher than that of the conventional TEOS-coated nanoparticles. In addition, the surface coating of SiO2 caused a decrease in magnetization with an increase in the coating-layer thickness, which was comparable to the general tendency associated with increasing the weight per unit particle. However, it was somewhat superior to those of the conventional TEOS method because of the difference in morphology.

We report the characteristic magnetic behaviors of nonemissive (N416) and green emissive (G416) Cs4PbBr6 perovskite crystals. N416 exhibits a diamagnetic behavior, while G416 shows an additional su...

A selenous acid (H2SeO3) precursor was intercalated as biselenite (HSeO3−) ions into the interlayer gallery of carbonated magnesium aluminum layered double hydroxide (MgAl-LDH) in aqueous solution. Reduction reaction of selenous ions by aqueous hydrazine solution produced polyselenide intercalated LDHs which were consecutively exchanged with iodide through redox reaction under iodine vapor. The polyselenide containing LDHs adsorbed iodine vapor spontaneously and triiodide was incorporated in the interlayer space followed by formation of selenium polycrystalline phase. Two dimensional framework of MgAl-LDH is strong enough to resist against the reducing power of hydrazine as well as oxidation condition of iodine. The SEM data demonstrated that the shapes of LDH polycrystalline have little changed after the above redox reactions. The polyselenide and iodide LDH products were analyzed by XRD, Infrared and Raman spectra which strongly suggested the horizontal arrangement of polyselenide and triiodide in gallery space of LDHs.

Highly dense CuInSe 2 (CISe) thin films were electrochemically deposited on Mo-coated soda-lime glass substrates in aqueous solution. Three compounds, CuCl 2 , InCl 3 , and SeO 2 , were used as precursors with glycine or oxalic acid as complexing agents. The deposition process was carefully selected through preliminary study of the individual electrochemical properties of the three precursors. To achieve ideal stoichiometry and uniform deposition of CISe thin films, the reaction temperature and acidity of precursor solution were investigated. As the reaction temperature increased, Cu deficiency was observed in the CISe thin film. The density and surface morphology of CISe films prepared by one-step electrodeposition were affected strongly by the acidity of deposition solution. The addition of HCl to solution improved the density and surface roughness of as-deposited CISe films. Denser and larger grain size CISe polycrystalline films were prepared in oxalic acid solution. Two-step heat treatments for the prepared CISe samples were applied to fabrication of CISe photovoltaic devices without an additional Se source.

Improving the stability and tuning the optical properties of semiconducting perovskites are vital for their applications in advanced optoelectronic devices. We present a facile synthetic method for hybrid composites of perovskites and metal-organic frameworks (MOFs). A simple two-step solution-based method without organic surfactants was employed to make all-inorganic lead-halide perovskites (CsPbX3; X = Cl, Br, I, or mixed halide compositions) form directly in the pores of MIL-101 MOF. That is, a polar organic solution of lead halide (PbX2) was impregnated into the MOF pores to give PbX2@MIL-101, which was then subjected to a perovskite-formation reaction with cesium halide (CsX) dissolved in methanol. The compositions of the halogen anions in the perovskites can be modulated with various halide precursors, leading to CsPbX3@MIL-101 composites with X3 = Cl3, Cl2Br, Br2Cl, Br3, Br2I, I2Br, and I3 that exhibit gradual variation of band gap energies and tuned emission wavelengths from 417 to 698 nm.

The CuIn(x)Ga(1-x)Se2 (CIGS) using the solution-based fabrication method is attractive for thin film solar cells because of its possibilities for large-area and low-cost production. ZnO films between transparent conductive oxide (TCO) and the CdS films can improve the performances of CIGS thin-film solar cells. In this study, we investigated the characteristics of ZnO film between TCO and CIGS layers in a solar cell (AZO/ZnO/CdS/CIGS/Mo), which were deposited at various thicknesses to investigate the role of the films in CIGS solar cells. It was confirmed that the conversion efficiency of a CIGS solar cell depends on the ZnO film. For a ZnO film thickness of 80 nm, the highest power conversion efficiency that a solar cell achieved was J(sc) of 18.73 mA/cm2.

CuInS2 colloidal nanocrystals were synthesized via a facile solution-processed method, using a CuIn(OH)5 precursor. The Cu–In metal hydroxide precursor was prepared by co-precipitation in aqueous solution: an aqueous NaOH solution was reacted with a metal cation solution containing Cu2 + and In3 + ions at room temperature. Oleic acid was added as a surfactant and bis(trimethyldisilyl)sulfide was injected to provide a sulfur source for the formation of CuInS2 nanocrystals. The CuInS2 colloidal nanocrystals had mixed crystal structures of zincblende and wurtzite, confirmed by XRD and TEM. The CuInS2 nanoparticles were of average size 5.6 nm and had a 1:1:2 chemical composition. Paste of the as-prepared CuInS2 nanocrystals were coated as a thin film absorber layer for photovoltaic cells by doctor blading, yielding cell efficiency of 1.26%.

We propose a reaction scheme to selectively separate lithium ions from an aqueous urea solution by formation of lithium aluminum layered double hydroxide (LDH) on aluminum metal foils. The repeated cycles of adsorption and desorption of lithium ions are possible using the topotactic reaction of lithium salts with Al(OH)3 grown on an aluminum metal surface in aqueous solution. The urea and lithium salt concentration, pH, and reaction time are critical parameters for modulating the maximum yield of recovered lithium quantity, which is 8 μg/cm2 of aluminum metal surface. The adsorbed lithium is strongly correlated with saturation conditions of lithium and urea, dependent upon competition between the rate of crystal growth and that of nucleation of LDH. The kinetic study of sorption and surface characterization provides a possible mechanism for the lithium exchange reaction and suggests the facile methodology of a lithium recovery system.

The heterometallic Cu–In complex salt [Cu(III) (dtc)2][In(III)I4](1) (dtc = S2CNEt2, diethyldithiocarbamate) was prepared by reactions of Cu(II) (dtc)2 and In(III)I3 in benzene solution. As a redox reaction, Cu(II) (dtc)2 was oxidized to [Cu(III) (dtc)2]+, and In(III)I3 was changed to [In(III)I4]−. The square−planar Cu(III)S4 local symmetry of 1 involves a distorted octahedral coordination environment via long−range intermolecular interactions and represents a new one-dimensional structure of [Cu(III) (dtc)2]+ units. The crystal packing system of 1 consists of many [Cu(III) (dtc)2]+ chains surrounded by six parallel chains without solvent molecules. The infrared spectra of 1 showed a higher-frequency C–N thioureide bond in Cu(III) (dtc)2 than that of pristine Cu(II) (dtc)2, which has a lower oxidation state due to the Cu(II) center.

The direct synthesis of nanostructured electrode materials on three-dimensional substrates is important for their practical application in electrochemical cells without requiring the use of organic additives or binders. In this study, we present a simple two-step process to synthesize a stable core-shell structured cobalt sulfide/cobalt aluminum hydroxide nanosheet (LDH-S) for pseudocapacitor electrode application. The cobalt aluminum layered double hydroxide (CoAl-LDH) nanoplates were synthesized in basic aqueous solution with a kinetically-controlled thickness. Owing to the facile diffusion of electrolytes through the nanoplates, thin CoAl-LDH nanoplates have higher specific capacitance values than thick nanoplates. The as-grown CoAl-LDH nanoplates were transformed into core-shell structured LDH-S nanosheets by a surface modification process in Na2 S aqueous solution. The chemically robust cobalt sulfide (CoS) shell increased the electrochemical stability compared to the sulfide-free CoAl-LDH electrodes. The LDH-S electrodes exhibited high electrochemical performance in terms of specific capacitance and rate capability with a galvanostatic discharge of 1503 F g-1 at a current density of 2 A g-1 and a specific capacitance of 91 % at 50 A g-1 .

We synthesized binder-free Co(OH)2 nanocrystals on nickel electrodes by the ammonia transfer method in an aqueous solution and kinetically-controlled their thickness and height to enhance the capacitance through the facile diffusion of electrolytes in the nanocrystals. As thinner Co(OH)2 films were developed, the specific capacitance increased up to 1260 F g(-1) at a current density of 10 A g(-1). A thin layer of graphene oxide (GO) was used to wrap the Co(OH)2 nanocrystals to create a pseudocapacitor with high specific capacitance and good cyclic stability. This synthetic strategy enabled us to maximize the electrochemical cell performance, reaching a specific capacitance of 2710 F g(-1) under 10 A g(-1). The GO coating provides an effective method to increase adhesion on the nickel electrodes and to reduce the decomposition of Co(OH)2 during the charge-discharge process under high pH conditions. The prepared GO/Co(OH)2 nanocomposite layers provided not only high electron mobility but also ionic conductivity, especially when operated at a high current density.

We tested for the association of HTR1A and 5-HTT genetic polymorphisms with treatment response to mirtazapine and evaluated the interactive effect between the polymorphisms in 283 patients with major depressive disorder. Korean subjects with diagnosis of major depressive disorder using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis I disorders were recruited. Clinical symptoms were evaluated using the 17-item Hamilton Depression Rating (HAMD-17) Scale at baseline and after 1, 2, 4, 8, and 12 weeks of treatment with mirtazapine. The genetic association of 5-HTTLPR and HTR1A+272GA with treatment response was analyzed. We found a significant association of the 12.12-repeat genotype of 5-HTT various number tandem repeat (VNTR) with a large percentage decline in HAMD-17 Scale score after 4, 8, and 12 weeks of treatment with mirtazapine. We also found that the frequency of the 12.12-repeat genotype was higher in responders than in nonresponders at week 8. The HTR1A+272GG genotype was significantly associated with a large percentage decline in HAMD-17 Scale score at 4, 8, and 12 weeks, although the genotypic frequencies were comparable between responders and nonresponders during the study period. Patients with the 12.12-repeat 5-HTT VNTR and GG of HTR1A+272GA showed the highest HAMD-17 Scale percentage reduction during the study period and a better treatment response status after 4 weeks. These results suggest that the interaction between HTR1A+272GA and 5-HTT VNTR is involved in the response to mirtazapine treatment and that a combination of these may be a useful marker for predicting treatment response to mirtazapine.

This work reports on the syntheses of copper-gallium bimetallic nanoparticles by ultrasound-assisted chemical reduction method in alcohol solutions to prepare CuGaS 2 thin films. Gallium metal (Ga) in the form of pellet was dispersed in tetraethylene glycol by ultrasonic treatment. The chemical reduction of copper sulfate (CuSO 4 ) into copper metal by NaBH 4 at the surface of the Ga droplets enabled the formation of Ga–Cu core–shell structure. The Ga droplets with submicrometer size were homogenously coated with ~40-nm Cu nanoparticles. The exothermic transition of the Ga–Cu core–shell nanocomposite materials occurred at 485 °C, which corresponds to the crystalline phase formation of γ-Cu 9 Ga 4 . Ga–Cu nanocomposites with a 1:1 ratio were deposited onto molybdenum substrate via electrophoretic deposition method as a precursor of CuGaS 2 , a p-type semiconductor. Mechanical pressing and sulfurization provided dense CuGaS 2 thin films with good crystallinity and high phase purity.

A polymer fiber film embedded with light-emitting inorganic perovskite nanocrystals (IPNCs) was prepared by multi-nozzle electrospinning of the solutions containing the inorganic perovskite (IP) precursors (CsX and PbX2) and polystyrene (PS). This is a simple and versatile method for direct confinement of nano-sized functional materials inside continuous fibers. The PL emission color of the hybrid fibers can be modulated using combinations of red (R), green (G), and blue (B) precursor solutions in one-step multi-nozzle electrospinning, leading to seven colors: R, G, B, cyan, yellow, magenta, and white. Intriguingly, nanoscale optical spectral imaging of fibers revealed the existence of local emission centers with different emission wavelengths in R and B emission fibers due to rapid formation of IPNCs with mixed halogen contents. These PL imaging results provide a fundamental understanding of the optical properties of the directly formed IPNCs in the polymer matrix.

High-quality and millimeter-sized perovskite single crystals of CsPbBr

The effect of precursor viscosity, substrate temperature, and flow rate on CuInGaSe 2 nanoparticle-based thin films deposited by an electrostatic spray deposition (ESD) technique are studied. ESD is superior to pneumatic spraying because it produces nano-scale, self-dispersive (non-agglomerating), highly wettable (electrowetting) and adhesive droplets, which collectively yield a uniform coating on the substrate. The synthesized CuInGaSe 2 nanoparticles were added to 4 different solvents: ethanol (E), butyl carbitol (BC), ethylene glycol (EG), and diethylene glycol (DEG). Subsequently, the solvents were electrostatically sprayed onto a molybdenum-coated soda-lime glass substrate. The solvent that yielded the most uniform surface morphology for the coated materials was identified. The surface roughness of the coated CIGS thin film, which depends on viscosity and the substrate temperature, was studied by AFM characterization.

Large-scale (as much as 200 g in a batch) and surfactant-free syntheses of the CuInxGa1–xSe2 and the CuInxGa1–xS2 nanoparticles were investigated by employing a sonochemical process under ambient conditions. This synthetic approach eliminates the need for organic stabilizers, which may act as an insulator in the final device, and reduces the number of reaction steps for synthesis of high-quality CISe nanocrystals. We also demonstrate the solution-based fabrication of the thin film photovoltaic devices with a conversion efficiency of 2.62 % by using nanocrystal-based inks. The device was fabricated with 2 μm of a CIGS absorber layer on Mo-coated soda lime glass, 70 nm of a chemical-bath-deposited CdS layer, 100 nm of an intrinsic ZnO layer, followed by 800 nm of a Al-doped ZnO layer. Finally, a patterned Ag (200 nm) grid was deposited on the top of the device. The current results offer a promising alternative for solution-based CIGSe thin film solar cells, with a higher efficiency.

This study investigated the preparation of copper–indium bimetallic nanoparticles through the borohydride reduction in an alcohol solution for application in ink-coating and sputtering target materials. Copper, indium metal and copper–indium intermetallic materials were synthesized by reacting CuCl 2 and InCl 3 with NaBH 4 in 2-propanol (IPA) and tetraethylene glycol (TEG) at room temperature. The Cu–In samples contained Cu 2 In and CuIn phases with particle sizes of 10–100 nm and 30–200 nm in both the IPA and TEG solutions, respectively. The nanoparticulate Cu–In precursor layer was coated onto a soda-lime glass through spin-casting, where the Cu–In intermetallic phases of Cu 2 In and Cu 11 In 9 were produced through heat treatment in Ar gas and a microstructured CuInSe 2 layer was produced in a selenium atmosphere. Cu, In, Cu–In intermetallic nanoparticles and the films were characterized using powder X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analyses.

Serotonergic genes have been implicated in mood disorders, alcoholism and certain personality traits. The goal of this study was to investigate the relationship between personality traits and several important genes in the serotonin system. The participants included 146 healthy adults with no history of psychiatric disorders or other physical illness during the last 6 months. All participants were tested by the Temperament and Character Inventory (TCI) and genotyped serotonin transporter, serotonin receptors (5-HT 2A and 5-HT 6 ) and tryptophan hydroxylase gene polymorphisms. Genotyping was analyzed with polymerase chain reaction. Differences in TCI dimensions and sub-scales among three groups were examined with ANOVA. Our result suggested that 5-HT 2A receptor gene polymorphism (A-1438G) appears to be associated with self-determinism and self-transcendence (ST). Our result also indicated a significant relationship between 5-HT 6 receptor gene polymorphism (C267T) and ST. Further studies of polymorphisms of other genes and their interactions may clarify the complex relationship between personality and genes.

This study investigated the possible effect of the –1438A/G single-nucleotide polymorphism in the promoter region of the serotonin 2A receptor (5-HTR2A) gene on major depressive disorder (MDD) in a Korean population. This polymorphism was analyzed in 189 patients with MDD and in 148 unrelated healthy controls using a case-control design, which revealed a significant difference in the genotype distributions (χ2 = 10.78, d.f. = 2, p = 0.005). The frequency of the –1438G allele was also much higher in MDD patients than in normal controls (χ2 = 7.20, p = 0.007; OR = 1.52, 95% CI 1.12–2.06). We also found significantly more carriers of the G allele (GG+AG genotypes) in MDD patients than in normal controls (χ2 = 10.18, p = 0.001; OR = 2.46, 95% CI 1.40–4.32). Our results support the hypothesis that the –1438A/G polymorphism of the promoter region of the 5-HTR2A gene is associated with MDD patients in a Korean population.

The genes involved in signal transduction are major candidates in association studies on affective disorders and responses to antidepressants. We investigated whether the C825T polymorphism of the beta3 subunit of G protein (GNB3) gene is associated with the symptom severity or treatment response of major depressive disorders (MDDs) in a Korean sample of 106 MDD patients; our study also included 133 healthy controls. Hypertensive subjects were excluded from the study because association between GNB3 variants and hypertension has been reported in previous studies. We found significantly more carriers of the 825T allele in MDD patients than in normal controls (chi(2)=6.37, P=0.012; OR=2.19, 95% CI 1.18-4.05). The T-allele carriers showed higher scores than those with the CC genotype in the baseline total and in some subcategories of the Hamilton Depression Rating Scale (P

A nanoink solution-based process was developed as a low-costing method for the fabrication of Cu(In,Ga)Se2 (CIGSe) thin-film photovoltaic cells. The sonochemical synthesis of CIGSe nanocrystals of the nanoink through step-by-step mixing of the reactants was investigated. To achieve the ideal stoichiometry of Cu(In0.7 Ga0.3 )Se2 to tune the bandgap and to fabricate high-efficiency photovoltaic cells, the synthetic parameters, the concentration of hydrazine, and the amount used of the gallium precursor were investigated. As the hydrazine concentration increased, gallium loss was observed in the CIGSe product. The gallium content in the reactant mixture strongly affected the metal stoichiometry of the prepared CIGSe nanocrystals. The nanoink solution based fabrication of thin-film photovoltaic cells was also explored, and the resulting device showed a conversion efficiency of 5.17 %.