3D Zinc Research Articles

A 3D aluminoborate open framework interpenetrated by 2D zinc-amine coordination-polymer networks in its 11-ring channels.

A new inorganic-organic hybrid solid, [Zn(dap)2 ][AlB5 O10 ], combining the structural features of 3D open-framework inorganic solids and 2D metal-organic coordination polymers has been synthesized under solvothermal conditions. The compound displays extensive luminescence and moderate second-harmonic-generation efficiency.

Fabrication of 1D ZnO nanostructures on MEMS cantilever for VOC sensor application

This study reports the fabrication method and sensing performance for novel 1D zinc oxide (ZnO) nanorods and nanotubes grown on nickel MEMS cantilevers. The fabrication of the nanostructures and the cantilevers are simple and low-cost using standard lithography, electrodeposition, and hydrothermal etching processes. 1D ZnO nanostructures increase the total sensitive area for biological and chemical sensor applications. We performed experiments with various VOCs with a real-time sensor system developed in our laboratory. While Ni microcantilevers produced no signal, ZnO nanostructure coated microcantilevers showed good sensitivity and repeatable changes. Furthermore, the nanotube coated microcantilevers showed more than 10 fold increase in sensitivity compared to the nanorod coated microcantilevers which can be explained to the fact that ZnO nanotubes have higher surface area and subsurface oxygen vacancies and these provide a larger effective surface area with higher surface-to-volume ratio as compared to ZnO nanorods. The tests are performed using dynamic mode of operation near resonant frequency using magnetic actuation and optical sensing. The phase stability and the limit of detection of ZnO nanotube coated microcantilevers exposed to diethylamine (DEA) were 0.02° and lower than 10ppm, respectively. ZnO nanostructure coated microcantilevers have good potential for VOC sensor applications especially for amine groups.

Structural and spectral properties of a zinc(II) coordination polymer: A combined experimental and theoretical study

A novel 1D zinc(II) coordination polymer [Zn(bbbm)Cl2]n (where bbbm=1,4-bis(N-benzimidazolyl)butane) was synthetized by ZnCl2 and bbbm ligand under hydrothermal conditions, and its structural and spectral properties were studied by both experimental and theoretical techniques. The center zinc(II) ion displays four-coordinated in a tetrahedral geometry by two chloride anions and two N atoms of distinct bbbm ligands. Adjacent chains are further connected into a 2D layer structure through π–π stacking interactions. Vibrational frequencies of [Zn(bbbm)Cl2]n have been calculated using DFT/B3LYP/TZVP method, and well reproduced IR data. Furthermore, the vertical excitation energies from time-dependent DFT calculation confirmed that the fluorescent peaks at 385nm and 450nm could respectively be assigned to the π→π* transition within the bbbm ligands and π→n transition from chloride anion to bbbm ligand.

Blue emission of a 2D non-interpenetrated zinc coordination polymer constructed through saturated fatty acid ligand

We report a new non-interpenetrated 2D zinc coordination polymer, [Zn(AA)(BPHY)]n (1) (H2AA=adipic acid, BPHY=1,2-bis(4-pyridyl)hydrazine), which is a mixed ligand complex. The solid-state sample of 1 exhibits tunable blue emission excited by UV light with the wavelengths from 320nm to 380nm. The luminescent mechanism of 1 has been studied by theoretical calculation.

Solution-processed Cu2ZnSnS4 superstrate solar cell using vertically aligned ZnO nanorods

One-dimensional (1D) zinc oxide (ZnO) nanostructures are considered to be promising materials for use in thin film solar cells because of their high light harvesting and charge collection efficiencies. We firstly report enhanced photovoltaic performances in Cu2ZnSnS4 (CZTS) thin film solar cells prepared using ZnO nanostructures. A CdS-coated, vertically well-aligned ZnO nanorod (NR) array was prepared via a hydrothermal reaction and nanocrystal layer deposition (NCLD) and was used as a transparent window/buffer layer in a CZTS thin film photovoltaic. A light absorber CZTS thin film was prepared on the CdS/ZnO NRs in air by depositing a non-toxic precursor solution that was annealed in two steps at temperatures up to 250 °C. The crystallized CZTS phase completely infiltrated the CdS/ZnO NR array. The nanostructured ZnO array provided improved light harvesting behavior compared to a thin film configuration by measuring UV–vis transmittance spectroscopy. The prepared CZTS/CdS/ZnO NR device exhibited a solar energy conversion efficiency of 1.2%, which is the highest efficiency yet reported for nanostructured superstrate CZTS solar cells.

Electromechanical properties of 1D ZnO nanostructures: nanopiezotronics building blocks, surface and size-scale effects

One-dimensional (1D) zinc oxide nanostructures are the main components of nanogenerators and central to the emerging field of nanopiezotronics. Understanding the underlying physics and quantifying the electromechanical properties of these structures, the topic of this research study, play a major role in designing next-generation nanoelectromechanical devices. Here, atomistic simulations are utilized to study surface and size-scale effects on the electromechanical response of 1D ZnO nanostructures. It is shown that the mechanical and piezoelectric properties of these structures are controlled by their size, cross-sectional geometry, and loading configuration. The study reveals enhancement of the piezoelectric and elastic modulus of ZnO nanowires (NW) with diameter d > 1 nm, followed by a sudden drop for d < 1 nm due to transformation of NWs to nanotubes (NTs). Degradation of mechanical and piezoelectric properties of ZnO nanobelts (NBs) followed by an enhancement in piezoelectric properties occurs when their lower dimension is reduced to <1 nm. The latter enhancement can be explained in the context of surface reconfiguration and formation of hexagon-tetragon (HT) pairs at the intersection of (21[combining macron]1[combining macron]0) and (011[combining macron]0) planes in NBs. Transition from a surface-reconstructed dominant to a surface-relaxed dominant region is demonstrated for lateral dimensions <1 nm. New phase-transformation (PT) kinetics from piezoelectric wurtzite to nonpiezoelectric body-centered tetragonal (WZ → BCT) and graphite-like phase (WZ → HX) structures occurs in ZnO NWs loaded up to large strains of ∼10%.

Effects of Mg doping on optical and CO gas sensing properties of sensitive ZnO nanobelts

We report the synthesis, optical characterization and enhanced carbon monoxide (CO) gas sensing properties of magnesium (Mg) doped 1D zinc oxide (ZnO) nanobelts obtained via a vapor transport method.

New 2D zinc phosphonates with heptanuclear units, reversible dehydration–hydration and bright luminescence

Two new zinc phosphonates with formulas [Zn18(L)12(H2N(CH2)4NH2)2]·25.5H2O (1) and [Zn9(L)6(HN(C2H4NH2)2)2]·10H2O (2) have been synthesized starting from zinc acetate, 1-C10H7-CH2N(CH2COOH)(CH2PO3H2) (H3L) and 1,4-butanediamine (for 1)/diethylenetriamine (for 2). Compounds 1 and 2 are characterized by single-crystal X-ray crystallography, powder XRD, elemental analysis, IR spectroscopy, and thermogravimetric (TG) analysis. In the crystal structures of compounds 1 and 2, Zn7 heptanuclear clusters are bridged by [Zn2(H2N(CH2)4NH2)] and [Zn(HN(C2H4NH2)2)] fragments, respectively, to form two-dimensional (2D) frameworks. Compound 1 is a dynamic framework upon the dehydration–hydration process and displays bright purple emission, while the framework of compound 2 is stable up to 250 °C under an air atmosphere. And the luminescence of compound 2 can be tuned by heating treatment.

Synthesis, Structure and Properties of Two Novel 2D Zinc(II) Coordination Polymers based on Fluconazole and Benzene Carboxylic Acid

E-mail: pgh1919@163.comReceived June 5, 2013, Accepted September 13, 2013Key Words : Triple hydrogen bond, Coordination polymer, Fluconazole, UV-vis spectra, FluorescenceNowadays, the design and synthesis of coordination poly-mers have aroused great interest owing to their intriguingaesthetic structures and potential applications in nonlinearoptics, gas storage, ion exchange, luminescence, magnetismand catalysis.

Two novel 3D porous Copper(II) and Zinc(II) frameworks with 1,3-di-(1,2,4- triazole-4-yl)benzene: 4-connected dmp network versus 6-connnected α-Po network based on trinuclear Zinc(II) clusters

Used versatile multidentate benzene-based bis-triazole ligand 1,3-di-(1,2,4-triazole-4-yl)benzene (L), two novel 3D porous Copper(II) and Zinc(II) frameworks, namely {[Cu(μ 2 -L) 2 (SiF 6 )(H 2 O)]·0.5H 2 O} n ( 1 ) and {[Zn 3 (μ 3 -L) 6 ](NO 3 ) 6 } n ( 2 ), have been isolated under the hydrothermal conditions. The structural analysis reveals that 1 presents a 3D microporous Copper(II) framework with the novel 4-connected 6 3 8 3 dmp topology containing infinite right- and left-handed Cu(μ 2 -L) 2 helical chains. While 2 presents a 3D cluster-based nano-porous cationic host framework with 6-connected α-Po-related (4 12 6 3 ) topology, in which trinuclear Zinc(II) clusters can be defined as basic nodes. The varied temperature magnetic susceptibility of 1 (from 300 to 2 K) and solid state luminescent property of 2 also have been investigated. Two novel 3D porous frameworks with 1,3-di-(1,2,4-triazole-4-yl)benzene have been isolated. 1 presents a 3D microporous Cu(II) framework with 4-connected 6383 dmp topology, while 2 presents a 3D cluster-based nano-porous framework with 6-connected α-Po-related topology. • Two novel 3D porous Copper(II) and Zinc(II) frameworks have been isolated. • 1 presents a 3D Copper(II) framework with 4-connected 6383 dmp topology. • 2 presents a 3D cluster-based framework with 6-connected α-Po-related (41263) topology.

Assembly of 1D and 2D zinc(II) coordination polymers from flexible polyimidazolyl-based ligands

Abstract Reactions of Zn(NO3)2∙ 6H2O with 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (titmb) in the presence of 1,4-benzenedicarboxylic acid (1,4-H2BDC) or 1,3-benzenedicarboxylic acid (1,3-H2BDC) under hydrothermal conditions afforded one 1D and one 2D coordination polymers [Zn3(titmb)2(1,4-BDC)3(H2O)6] (1) and [Zn2(titmb)(1,3-BDC)2(H2O)] (2), respectively. Similar reactions of Zn(NO3)2∙ 6H2O with 1,3-bis(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (bitmb) and 1,4-H2BDC gave rise to one 2D coordination polymer [Zn2(bitmb)2(1,4-BDC)2] (3). Compound 1 has a 1D linear chain formed from linking 24-membered [Zn2(titmb)2] metallamacrocycles and [Zn(1,4-BDC)(H2O)2] units via imidazolyl groups of titmb ligands. Compound 2 has a 2D network assembled from connecting spiral [Znn(1,3-BDC)n] chains with titmb linkers, while compound 3 also has a 2D network formed by linking 24-membered [Zn2(bitmb)2] metallamacrocycles via 1,3-BDC bridges. The ligands titmb and bitmb in compounds 1–3 adopt less-common cis–trans–trans and cis–trans conformations, respectively. Their thermal and photoluminescent properties were also investigated.

One-dimensional ZnO nanostructures: fabrication, optoelectronic properties, and device applications

One-dimensional (1D) zinc oxide (ZnO) nanostructures have been extensively and intensively studied for several decades not only for their extraordinary chemical and physical properties, but also for their current and future different electronic and optoelectronic device applications. This review provides a brief overview of the progress of different synthesis methods and applications of 1D-ZnO nanostructures. Morphology of ZnO nanostructures grown by various methods and progress in the optical properties are briefly described. Using low-temperature photoluminescence (LTPL) study, detailed informations about the defect states and impurity of such nanostructures are reported. Improvement of field emission properties by modifying the edge of 1D-ZnO nanostructures is briefly discussed. Applications such as different sensors, field effect transistor, light-emitting diodes (LEDs), and photodetector are briefly reviewed. ZnO has large exciton binding energy (60 meV) and wide band gap (3.37 eV), which could lead to lasing action based on exciton recombination. As semiconductor devices are being aggressively scaled down, ZnO 1D nanostructures based resistive switching (RS) memory (resistance random access memory) is very attractive for nonvolatile memory applications. Switching properties and mechanisms of Ga-doped and undoped ZnO nanorods/NWs are briefly discussed. The present paper reviews the recent activities of the growth and applications of various 1D-ZnO nanostructures for sensor, LED, photodetector, laser, and RS memory devices.

Piezoelectric two-dimensional nanosheets/anionic layer heterojunction for efficient direct current power generation

Direct current (DC) piezoelectric power generator is promising for the miniaturization of a power package and self-powering of nanorobots and body-implanted devices. Hence, we report the first use of two-dimensional (2D) zinc oxide (ZnO) nanostructure and an anionic nanoclay layer to generate piezoelectric DC output power. The device, made from 2D nanosheets and an anionic nanoclay layer heterojunction, has potential to be the smallest size power package, and could be used to charge wireless nano/micro scale systems without the use of rectifier circuits to convert alternating current into DC to store the generated power. The combined effect of buckling behaviour of the ZnO nanosheets, a self-formed anionic nanoclay layer, and coupled semiconducting and piezoelectric properties of ZnO nanosheets contributes to efficient DC power generation. The networked ZnO nanosheets proved to be structurally stable under huge external mechanical loads.

Ultrafast Formation of ZnO Nanorods via Seed-Mediated Microwave Assisted Hydrolysis Process

One dimensional (1D) zinc oxide, ZnO nanostructures have shown promising results for usage in photodiode and optoelectronic device due to their high surface area. Faster and conventional method for synthesis ZnO nanorods has become an attention for researcher today. In this paper, ZnO nanorods have been successfully synthesized via two-step process, namely alcothermal seeding and seed-mediated microwave hydrolysis process. In typical process, the ZnO nanoseeds were grown in the growth solution that contained equimolar (0.04 M) of zinc nitrate hexahydrate, Zn (NO3).6H2O and hexamethylenetetramine, HMT. The growth process was carried inside the inverted microwave within 5- 20 s. The effect of growth parameters (i.e. concentration, microwave power, time reaction) upon the modification of ZnO morphology was studied. ZnO nanostructures were characterized by Field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD). The densities of nanorods were evaluated by the Image J analysis. It was found that the morphology (e.g. shape and size) of nanostructures has changed drastically with the increment of growth solution concentration. The density of ZnO nanorods was proven to increase with the increasing of reaction time and microwave power. We hypothesize that the microwave power might enhance the rate of nucleation and promote the faster nanostructure growth as compared with the normal heating condition due to the superheating phenomenon. This method might promote a new and faster alternative way in nanostructure growth which can be applied in currently existing application.

Ultrathin 2D Coordination Polymer Nanosheets by Surfactant-Mediated Synthesis

Low-dimensional nanostructures offer a host of intriguing properties which are distinct from those of the bulk material, owing to size-confinement effects and amplified surface areas. Here, we report on the scalable, bottom-up synthesis of ultrathin coordination polymer nanosheets via surfactant-mediated synthesis and subsequent exfoliation. Layers of a two-dimensional (2D) zinc coordination polymer are self-assembled in the interlamellar space of a reverse microemulsion mesophase into stacks of nanosheets interleaved with cethyltrimethylammonium bromide (CTAB) at regular intervals, thus giving rise to a lamellar hybrid mesostructure with a lattice period of ~8 nm and an underlying highly crystalline substructure. The basic structural motif is composed of 2D acetato-benzimidazolato-zinc layers of tetrahedrally coordinated zinc joined together by anionic acetate and benzimidazolate ligands. The hierarchical structure was studied by PXRD, TEM, EDX, EELS, AFM, and solid-state NMR spectroscopy, revealing a high level of order on both the atomic and mesoscale, suggesting fairly strong interactions along the organic-inorganic hybrid interface. Exfoliation of the hybrid material in organic solvents such as THF and chloroform yields sheet- and belt-like nanostructures with lateral sizes between 10's and 100's of nanometers and a height of about 10 nm measured by AFM, which precisely maps the basal spacing of the lamellar mesostructure; further exfoliation results in nanobelts with minimum sizes around 4 nm. Finally, the sheetlike nanostructures behave as morphological chameleons, transforming into highly regular multiwalled coordination polymer nanotubes upon treatment with organic solvents.

Zn2(VO4)(IO3): A Novel Polar Zinc(II) Vanadium(V) Iodate with a Large SHG Response

The synthesis, crystal and electronic structures, and optical properties of the first zinc(II) vanadium(V) iodate, namely, Zn2(VO4)(IO3), are reported. Zn2(VO4)(IO3) crystallizes in the noncentrosymmetric (NCS) and polar space group Pc (No. 7) with a = 5.2714(8) Å, b = 10.0402(11) Å, c = 5.5070(8) Å, β = 101.326(10)°, and Z = 2. It displays a novel three-dimensional (3D) network structure composed of ZnO5, ZnO6, VO4, and IO3 polyhedra. One-dimensional (1D) chains of edge-sharing ZnO5 polyhedra and 1D chains of corner-sharing ZnO6 octahedra along the c-axis are interconnected via corner-sharing into a two-dimensional (2D) zinc oxide layer, and such layers are bridged by both VO4 tetrahedra and IO3 groups into a 3D network. The polarity in the structure is imparted by the alignment of the stereochemically active lone pairs of the iodate anions along the c-axis. The second harmonics generation (SHG) measurements on powder samples of Zn2(VO4)(IO3) under 1064-nm laser radiation revealed a large response of ∼6 × KDP, which is Type I phase-matchable. Thermal stability and optical properties, as well as theoretical calculations based on DFT methods, were also performed.

Fabrication and characterization of zinc oxide nanofibers for renewable energy applications

Nanometer (nm) scale 1D zinc oxide (ZnO) nanofibers were fabricated through sol–gel processing and electrospinning of Polyvinyl alcohal (PVA) and zinc acetate precursors. The structure and morphologies of the zinc acetate/PVA precursor and ZnO nanofibers were studied by fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FE-SEM). Bead free smooth nanofibers with increased average diameters (278nm (5wt.%) and 423nm (15wt.%)) were obtained as the content of zinc acetate precursor was increased. The calcination temperature of 480°C was determined from TGA. FTIR, XRD and TGA studies carried out after calcinations, confirmed the formation of ZnO nanofibers by the appearance of a band at 472cm−1, characteristic ZnO pattern (i.e. peaks at ∼31.820, 34.331, 36.496, 47.569 and 57.168 2θ degree) and no weight loss after 480°C, respectively. The burning of polymer has also been confirmed by a significant decrease in average diameter (124nm (5wt.%) and 197nm (15wt.%)) of the ZnO nanofibers. Electrospinning has been found to be a simple and cost effective technique for the synthesis of ID ZnO nanofibers mat for potential applications in the renewable energy devices.

Isoreticular 3D zinc(II) frameworks constructed by unsymmetric 1,2,4-triazolate ligands: Syntheses, structures, and sorption properties

Abstract Three isoreticular metal-organic frameworks based on ternary zinc(II)/triazolate/X (X = OAc−, Cl−) metal azolate frameworks, namely [Zn(mtz)(OAc)]·H2O (1, Hmtz = 3-methyl-1,2,4-triazole), [Zn(etz)(OAc)]·0.5H2O (2, Hetz = 3-ethyl-1,2,4-triazole) and [Zn(metz)Cl]·0.25H2O (3, Hmetz = 3-methyl-5-ethyl-1,2,4-triazole), have been synthesized by changing the substituent groups on asymmetric 1,2,4-triazolates and auxiliary anions (OAc− or Cl−). These frameworks have a 3-connected 4.8.10-lvt-a topological network, which can be also simplified into a 4-connected lvt net by further denoting dinuclear [Zn2(triazole)2] subunits as a square-planar 4-connected node. 1 exhibits a porous structure with 1D (d = 3.0 A) effective channels showing the selective adsorption behaviors of CO2 over N2, whereas 2 and 3 are nonporous structures.

Hydrothermal synthesis, crystal structural, and thermal properties of a 1D zinc coordination polymer based on benzoate and flexible bis(benzimidazole) ligands

A new coordination polymer, [Zn(PhCOO)2(Bbbm)]n (I), where Bbbm = 1,1′-(1,4-butanediyl)bis-1H-benzimidazole, has been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TG and X-ray single-crystal diffraction. The complex crystallizes in the monoclinic system with space group P21/n, the unit cell parameters: a = 10.815(3), b = 20.516(6), c = 12.802(4) A, β = 102.025(3)°, V = 2778.2(14) A3, Z = 4. In this structure, the Zn2+ ion is in a distorted tetrahedral geometry, one-dimensional linear chain is constructed by Bbbm ligand with bis(monodentate) coordination mode.

A new precursor strategy to prepare ZnCo2O4 nanorods and their excellent catalytic activity for thermal decomposition of ammonium perchlorate

We present a new preparation of zinc cobaltite (ZnCo2O4) nanorods via a hydrothermal-annealing method. Zinc cobalt oxalate (ZnCo2(C2O4)3·6H2O) nanorods as the precursor have been firstly synthesized by solvothermal method at 120°C using the mixed solvents as the reaction medium without the assistance of soft/hard template. It is found that the mixed solvent plays an important role for zinc cobalt oxalate precursor nanorods and 1D growth of zinc cobalt oxalate precursor is gradually improved with the increasing ethylene glycol (EG) in the mixed solvent. The as-prepared zinc cobalt oxalate precursor (ZnCo2(C2O4)3·6H2O) nanorods can convert to 1D zinc cobaltite (ZnCo2O4) nanostructures while maintaining original frame structure. The obtained samples are characterized by means of XRD, SEM, TEM and HRTEM. Furthermore, the effect of zinc cobaltite (ZnCo2O4) nanostructures on the thermal decomposition of ammonium perchlorate (AP) is investigated by differential thermal analysis (DTA). The results show that the addition of zinc cobaltite (ZnCo2O4) nanorods to AP remarkably decreases the decomposition temperature. The as-prepared zinc cobaltite (ZnCo2O4) nanorods are promising as a high-performing ballistic modifier in AP-based composite solid rocket propellants.