Showing papers on "Ternary operation published in 2011"

Progress in research and development on MAX phases: a family of layered ternary compounds

Abstract: The MAX phases are a group of layered ternary compounds with the general formula Mn+1AXn (M: early transition metal; A: group A element; X: C and/or N; n = 1–3), which combine some properties of metals, such as good electrical and thermal conductivity, machinability, low hardness, thermal shock resistance and damage tolerance, with those of ceramics, such as high elastic moduli, high temperature strength, and oxidation and corrosion resistance. The publication of papers on the MAX phases has shown an almost exponential increase in the past decade. The existence of further MAX phases has been reported or proposed. In addition to surveying this activity, the synthesis of MAX phases in the forms of bulk, films and powders is reviewed, together with their physical, mechanical and corrosion/oxidation properties. Recent research and development has revealed potential for the practical application of the MAX phases (particularly using the pressureless sintering and physical vapour deposition coating rout...

Interaction of Microstructure and Interfacial Adhesion on Impact Performance of Polylactide (PLA) Ternary Blends

Abstract: Polyactide (PLA) was blended with an ethylene/n-butyl acrylate/glycidyl methacrylate (EBA-GMA) terpolymer and a zinc ionomer of ethylene/methacrylic acid (EMAA-Zn) copolymer. The phase morphology of the resulting ternary blends and its relationship with impact behaviors were studied systematically. Dynamic vulcanization of EBA-GMA in the presence of EMAA-Zn was investigated by torque rheology, and its cross-link level was evaluated by dynamic mechanical analysis. Reactive compatibilization between PLA and EBA-GMA was studied using Fourier transform infrared spectroscopy. The dispersed domains in the ternary blends displayed a “salami”-like phase structure, in which the EMAA-Zn phase evolved from occluded subinclusions into continuous phase with decrease in the EBA-GMA/EMAA-Zn ratio. An optimum range of particle sizes of the dispersed domains for high impact toughness was identified. Also, the micromechanical deformation process of these ternary blends was also investigated by observation of the impact-fra...

Light-harvesting multi-walled carbon nanotubes and CdS hybrids: Application to photocatalytic hydrogen production from water

Abstract: This study reports the synthesis and surface characterization of multi-walled carbon nanotubes (CNT), CdS, and metal catalyst (M) hybrids (CdS/CNT/M), and their novel application to photocatalytic hydrogen production under visible light (λ > 400 nm) in the presence of electron donor (Na2S and Na2SO3). In the binary hybrids between CNT and CdS (CdS/CNT) the CNT annealed at 500 °C (h-CNT) has the larger amount of hydrogen production than crude (c-CNT) or acid-treated CNT (a-CNT) due to highly improved purity and suitable work function. When hybridized with CdS and M, however, a-CNT has the largest amount of hydrogen production (a-CNT > h-CNT > c-CNT) even though all the CNTs have similar functional groups for binding metal catalyst on their surfaces. Photocurrent measurements also indicated that CdS/a-CNT/Pt ternary generates a higher photocurrent than that of CdS/a-CNT binary (ternary > binary > CdS alone). In such ternary hybrids, Pt, Ni, and Ru are found to be effective in catalyzing proton/water but other metals (Pd, Au, Ag, Cu) showed very low activities with the following order: Pt > Ni > Ru > Pd > Au > Ag > Cu. The enhanced hydrogen production in the binary and ternary hybrids is ascribed partially to suitably positioned work functions among the hybrid components and thereby vectorial charge transfer through the work function energy gradient. Detailed surface studies were also described using Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

Enhanced Photocatalytic and Photoelectrochemical Activity in the Ternary Hybrid of CdS/TiO2/WO3 through the Cascadal Electron Transfer

Abstract: The composite of different semiconductor nanoparticles may facilitate the charge separation and transfer because the difference in the band edge positions creates the potential gradient at the composite interface. For this purpose, the CdS–TiO2–WO3 ternary hybrid was successfully synthesized and characterized for the structural, optical, and morphological properties by X-ray diffraction, diffuse reflectance UV/visible absorption spectroscopy, high-resolution transmission electron micrography, and energy-dispersive X-ray analysis. The photocatalytic activity was tested by monitoring the photoreduction of polyoxometalate (POM: PMo12O403–) spectrophotometrically. The photoelectrochemical (PEC) property of the ternary hybrid electrode was also characterized by the linear sweep voltammetry, and the incident photon-to-current conversion efficiency was measured as a function of wavelength. The results of both the POM reduction and photocurrent tests indicated that the photocatalytic and PEC activities of the CdS...

Design of energy-efficient and robust ternary circuits for nanotechnology

Abstract: Novel high-performance ternary circuits for nanotechnology are presented here. Each of these carbon nanotube field-effect transistor (CNFET)-based circuits implements all the possible kinds of ternary logic, including negative, positive and standard ternary logics, in one structure. The proposed designs have good driving capability and large noise margins and are robust. These circuits are designed based on the unique properties of CNFETs, such as the capability of setting the desired threshold voltage by changing the diameters of the nanotubes. This property of CNFETs makes them very suitable for the multiple- V t design method. The proposed circuits are simulated exhaustively, using Synopsys HSPICE with 32 nm-CNFET technology in various test situations and different supply voltages. Simulation results demonstrate great improvements in terms of speed, power consumption and insusceptibility to process variations with respect to other conventional and state-of-the-art 32 nm complementary metal-oxide semiconductor and CNFET-based ternary circuits. For instance at 0.9 V, the proposed ternary logic and arithmetic circuits consume on average 53 and 40 less energy, respectively, compared to the CNFET-based ternary logic and arithmetic circuits, recently proposed in the literature.

Two-dimensional binary and ternary nanocrystal superlattices: the case of monolayers and bilayers

Abstract: The modular assembly of multicomponent nanocrystal (NC) superlattices enables new metamaterials with programmable properties. While self-assembly of three-dimensional (3D) binary NC superlattices (BNSLs) has advanced significantly in the past decade, limited progress has been made to grow 2D BNSLs such as monolayers and bilayers over extended areas. Here, we report the growth of large-area (∼ 1 cm(2)), transferable BNSL monolayers using the liquid-air interfacial assembly approach. The BNSL monolayers are formed by an entropy-driven assembly process with structures tunable by varying the NC size ratio. We further demonstrate the liquid-air interfacial assembly of BNSL bilayers which exhibit unique superlattice structures that have not been observed in the 3D BNSLs. As a further extension, bilayered ternary NC superlattices (TNSLs) are obtained by the cocrystallization of three types of NCs at the liquid-air interface.

Light-Responsive Capture and Release of DNA in a Ternary Supramolecular Complex

Abstract: The wavelength determines whether DNA is captured in a light-responsive ternary supramolecular complex or released (see scheme). The reversible binding of DNA is triggered by a photoisomerization, which switches the complex from a multivalent to a monovalent binding mode.

Highly active and stable PtRuSn/C catalyst for electrooxidations of ethylene glycol and glycerol

Abstract: Electrocatalytic oxidations of ethylene glycol and glycerol were studied over a carbon-supported PtRuSn catalyst (PtRuSn/C), which was prepared with a Pt:Ru:Sn atomic ratio of 5:4:1 using a colloidal method combined with a freeze-drying procedure at room temperature. The ternary PtRuSn/C catalyst was characterized by various physicochemical analyses such as X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and X-ray absorption-near-edge spectroscopy (XANES). The ternary PtRuSn catalyst showed noticeable modifications on the catalyst phases from Pt or PtRu in regards to structural and electronic features, such as a change in lattice parameter and electronic modification in unfilled d band states of Pt atoms. The structurally and electronically modified PtRuSn/C catalysts substantially enhanced the electrocatalytic activities for ethylene glycol and glycerol oxidations, resulting in larger peak currents and lower onset potentials of the electrooxidations. By incorporating the Ru and Sn elements onto the ternary PtRuSn/C catalyst, efficient oxidative removals of CO or CO-like carbonaceous intermediate species produced during the reaction were also possible, thus preventing poisoning of the active Pt sites. Consequently, significant enhancements of electrocatalytic activity and stability over the ternary PtRuSn/C catalyst could be achieved for the electrooxidations of ethylene glycol and glycerol.

Electron Transfer Cascade by Organic/Inorganic Ternary Composites of Porphyrin, Zinc Oxide Nanoparticles, and Reduced Graphene Oxide on a Tin Oxide Electrode that Exhibits Efficient Photocurrent Generation

Abstract: A bottom-up strategy has been developed to construct a multiple electron transfer system composed of organic/inorganic ternary composites (porphyrin, zinc oxide nanoparticles, reduced graphene oxide) on a semiconducting electrode without impairing the respective donor–acceptor components. The hierarchical electron transfer cascade system exhibited remarkably high photocurrent generation with an incident-photon-to-current efficiency of up to ca. 70%.

Tuning the synthesis of ternary lead chalcogenide quantum dots by balancing precursor reactivity.

Abstract: We report the synthesis and characterization of composition-tunable ternary lead chalcogenide alloys PbSexTe1-x, PbSxTe1-x, and PbSxSe1-x. This work explores the relative reaction rates of chalcoge...

Novel Solid‐State Li/LiFePO4 Battery Configuration with a Ternary Nanocomposite Electrolyte for Practical Applications

Abstract: Recently, considerable academic and industrial research effort has been directed toward solid-state rechargeable lithium batteries. They are considered to be a next-generation power source, play an important role in the energy storage fi eld, and are promising renewable energy sources for electric or hybrid electric vehicles. [ 1 , 2 ] However, high-performance solid electrolytes and the optimization of battery confi guration are major challenges before such batteries can be applied. [ 3 , 4 ] Currently, the optimization of various solid electrolyte properties is a serious issue. For instance, polymer electrolytes show poor thermal and mechanical performance limited by their organic nature. [ 5 ] Inorganic electrolytes exhibit imperfect performance in practical applications. [ 6 ] To combine the properties of inorganic materials with the advantages of liquid electrolytes, a quasi-solid electrolyte system based on liquid electrolytes immobilized on porous transporter matrices has been introduced. [ 7–9 ] It comprises solid matrices, which provide mechanical strength, and liquid electrolytes, which are responsible for ionic conductivity and other electrochemical properties. These are showing promise to overcome problems associated with conventional solid electrolytes. Another attractive option is the use of ionic liquids as non-volatile electrolytes in lithium batteries. [ 10 ] Traditional battery confi gurations prevent the development of solid-state lithium batteries because of low charge transport as a result of poor electrode–electrolyte interface compatibility, which limits the energy density and cycle life. The reactivity of the lithium metal anode and/or the poor thermal stability of the polymer also represents a safety hazard. In this Communication we report the fi rst design of a completely different solid-state Li/LiFePO 4 coin-type half-cell confi guration involving a novel quasi-solid-state composite electrolyte (SiO 2 /[BMP][TFSI]/LiTf, where [BMP][TFSI] is N -butylN methyl pyrrolidinium bis(trifl uoromethanesulfonyl)imide and LiTf is lithium trifl uoromethanesulfonate) to overcome these issues. Our aim was to design a high-performance solid-state battery for practical applications. The composite electrolyte was prepared by a nonaqueous sol-gel route (Figure S1, Supporting Information). [ 11 ] It is based on an amorphous mesoporous silica matrix immobilizing Li + conducting ionic-liquid electrolytes

Adsorption equilibria of O2, Ar, Kr and Xe on activated carbon and zeolites: single component and mixture data

Abstract: This work provides a set of experimental data on the adsorption of pure component, binary and ternary mixtures on activated carbon sample and two different zeolites at 303 K and moderate pressures (up to 10 bar for mixtures). Pure component data were measured by gravimetry and mixture data by volumetry coupled with chromatography. Results encourage more research on new materials and enhancement of adsorption-based separation processes with the proposed target.

Formation Pathway of CuInSe2 Nanocrystals for Solar Cells

Abstract: Copper, indium, and gallium chalcogenide nanocrystals (binary, ternary, and quaternary) have been used to fabricate high-efficiency thin-film solar cells. These solution-based methods are being scaled-up and may serve as the basis for the next generation of low-cost solar cells. However, the formation pathway to reach stoichiometric ternary CuInSe2 or any chalcopyrite phase ternary or quaternary nanocrystal in the system has not been investigated but may be of significant importance to improving nanocrystal growth and discovering new methods of synthesis. Here, we present the results of X-ray diffraction, electron microscopy, compositional analysis, IR absorption, and mass spectrometry that reveal insights into the formation pathway of CuInSe2 nanocrystals. Starting with CuCl, InCl3, and elemental Se all dissolved in oleylamine, the overall reaction that yields CuInSe2 involves the chlorination of the hydrocarbon groups of the solvent. Further, we show that the amine and alkene functional groups in oleyla...

High performance of a carbon supported ternary PdIrNi catalyst for ethanol electro-oxidation in anion-exchange membrane direct ethanol fuel cells

Abstract: In this paper, we report the synthesis of a carbon supported ternary PdIrNi catalyst for the ethanol oxidation reaction in anion-exchange membrane direct ethanol fuel cells (AEM DEFCs) We demonstrate that the use of the ternary PdIrNi catalyst at the anode of an AEM DEFC can increase the peak power density by more than 122% as compared with the use of the monometallic Pd catalyst, 69% as compared with the use of the bimetallic PdIr catalyst, and 44% as compared with the use of the bimetallic PdNi catalyst Cyclic voltammetry and chronopotentiometry analyses prove that the ternary PdIrNi catalyst is catalytically much more active and more stable than the monometallic Pd catalyst and the bimetallic PdIr and PdNi catalysts

Structural investigations on lead-free Bi1/2Na1/2TiO3-based piezoceramics

Abstract: In this study, recent results from our electron, X-ray, and neutron-diffraction experiments with emphasis on the binary Bi1/2Na1/2TiO3-BaTiO3 (BNT–BT) and ternary Bi1/2Na1/2TiO3–BaTiO3–K0.5Na0.5NbO3 (BNT–BT–KNN) system are presented and contrasted with literature. The experimental results clearly revealed a phase coexistence on the nanoscale level. A systematic study of superlattice reflections in conjunction with microstructural characteristics showed that the BNT-based systems have specific properties in common, which, however, strongly depend on composition. In situ transmission electron microscopy (TEM) electric field experiments unequivocally demonstrated the evolution of lamellar domains. Combining in situ TEM results with published in situ neutron-diffraction experiments, we proposed an electric field-induced phase transition that results in the giant unipolar and bipolar strain observed in specific compositions of the ternary system.

A bronze matryoshka: the discrete intermetalloid cluster [Sn@Cu12@Sn20](12-) in the ternary phases A12Cu12Sn21 (A = Na, K).

Abstract: The synthesis and crystal structure of the first ternary A–Cu–Sn intermetallic phases for the heavier alkali metals A = Na to Cs is reported. The title compounds A12Cu12Sn21 show discrete 33-atom i...

Interparticle forces in binary and ternary ordered powder mixes.

Abstract: An ultracentrifuge technique, previously described by Staniforth et al (1981), has been used to study the adhesion profiles of several binary and ternary ordered powder mixes of pharmaceutical interest. The adhesion profile of an ordered mix provides information about the proportion of drug powder adhering with different forces of attraction to the carrier excipient particle surface. The excipient particle size is shown to affect adhesion between the components of a binary ordered mix-recrystallized lactose formed more stable ordered mixes with drug powder when the carrier particle size was increased. Changes in the adhesion profile of each binary system on adding three different fine-powder excipients to form a ternary ordered mix are also examined. The physical properties of carrier particles and the charge interactions of a third powder component with previously formed binary ordered mixes, are found to influence the physical stability of ternary ordered mixes.

Topological insulators in ternary compounds with a honeycomb lattice.

Abstract: We investigate a new class of ternary materials such as LiAuSe and KHgSb with a honeycomb structure in Au-Se and Hg-Sb layers. We demonstrate the band inversion in these materials similar to HgTe, which is a strong precondition for existence of the topological surface states. In contrast with graphene, these materials exhibit strong spin-orbit coupling and a small direct band gap at the $\ensuremath{\Gamma}$ point. Since these materials are centrosymmetric, it is straightforward to determine the parity of their wave functions, and hence their topological character. Surprisingly, the compound with strong spin-orbit coupling (KHgSb) is trivial, whereas LiAuSe is found to be a topological insulator.

Organic Semiconductor:Insulator Polymer Ternary Blends for Photovoltaics

Abstract: Ternary blends of poly(3-hexylthiophene): Photovoltaic Devices [6,6]-phenyl C(61)-butyric acid methyl ester (P3HT:PC(61)BM) and the insulating bulk polymers high-density polyethylene (HDPE), isotactic- and atactic polystyrene (i-PS, a-PS), are investigated. Addition of up to approximate to 50 wt% of the electronically inert, semicrystalline HDPE and i-PS to the organic semiconducting system does not significantly degrade the performance of photovoltaic devices fabricated with these ternary blends.

Ultrasmall color-tunable copper-doped ternary semiconductor nanocrystal emitters.

Abstract: Synthesis of light-emitting dispersed semiconductor nanocrystals with tunable emission has been widely studied in the last two decades because of their potential applications in photovoltaics, optoelectronics, and biology. Soon after the development of high-quality CdSe nanocrystals with spectacular size-dependent tunable excitonic emission in the entire visible window, simplification of the synthetic method, stabilization of the emission, surface functionalization of the nanocrystals, design of non-cadmium nanocrystal emitters, fabrication of different kinds of composition-tunable multifunctional alloy nanocrystals, and related photophysical properties have been widely investigated for both fundamental understanding and their implementation in day-to-day developing technology. Analysis of up to date literature reports reveals that biological applications require strongly emitting, small and nontoxic nanocrystals preferably with excitation in the visible window, light-emitting diodes require nanocrystals having large Stokes shift and high quantum efficiency, and for solar cells nanocrystals having visible/near-IR (NIR) absorption and/or ternary/ quaternary nanocrystals with excess of either of the charge carriers (electron or hole) 11] are preferred. So far, no nanocrystal emitters having all such required properties have been reported, and thus further investigations are required to obtain new materials with new properties that would be suitable for versatile applications. We have now designed a new series of ultrasmall (< 2.5 nm), nearly fixed size, alloyed nanocrystals composed of Cu–Zn–In–Se ions which show composition-dependent tunable emissionover most of the visible window. In addition, these nanocrystals are cadmium-free and have aqueous dispersibility, photostability, large Stokes shifts, and high emission intensity (quantum yield (QY) = 25–30%), which makes them a versatile light-emitting nanoscale materials providing one-step solutions for various applications. The fundamental designing principle of these nanocrystals involves a mechanism whereby composition-variable alloy formation tunes the optical bands from lower to higher energy and vice versa. Here we report details of the synthesis, chemistry of formation, and composition-variable optical tuning of these fixed-size alloy nanocrystals. In addition, aqueous dispersibility and photovoltaic properties of these nanocrystals were investigated. The alloy nanocrystals were synthesized by simultaneous precipitation and surface cation-exchange protocols. Injection of a selenium precursor into a mixture of Zn, In, and Cu salts at 220 8C (see Experimental Section) results in copperdoped zinc indium selenide alloy nanocrystals whose absorption and emission wavelengths are determined by the In:Zn ratio of the reaction mixture. Further addition of Zn with continuous annealing slowly shifts both absorption and emission bands to the blue in a surface ion-exchange process. Successive photoluminescence (PL) spectra, absorption (UV/ Vis) spectra, and a schematic model of surface cation exchange for a typical alloying process are shown in Figure 1a–c. With an initial Zn:In ratio of 1:2, the emission appears at about 660 nm soon after injection of the Se precursor and is tuned up to 575 nm (Figure 1a) on introduction of additional Zn precursor, while for an initial Zn:In ratio of 1:1, the emission appears at about 620 nm and is tuned further to the blue, to 540 nm (Figure 1 b), that is, a total

Ternary Pt−Fe−Co Alloy Electrocatalysts Prepared by Electrodeposition: Elucidating the Roles of Fe and Co in the Oxygen Reduction Reaction

Abstract: An electrodeposition-based protocol for the synthesis of ternary Pt−Fe−Co electrocatalysts for the oxygen reduction reaction (ORR) has been developed. The eletrodeposition method suits the purpose ...