Synthesis and characterization of pure cubic zirconium oxide nanocrystals by decomposition of bis-aqua, tris-acetylacetonato zirconium(IV) nitrate as new precursor complex

Pure zirconium oxide (ZrO₂) nanocrystals with diameters 10-30 nm are fabricated from bis-aqua, tris-acetylacetonato zirconium(IV) nitrate; [Zr(acac)₃(H₂O)₂](NO₃); by thermal decomposition. The different combinations of oleylamine, or polyethyleneglycol (PEG) and triphenylphosphine, were added as surfactants to control the particle size. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) spectroscopy, photoluminescence spectroscopy (PL), Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to depict the phase and morphology. The synthesized ZrO₂ nanoparticles have a cubic structure. The FT-IR spectrum showed the purity of obtained ZrO₂ nanocrystals with cubic phase. The UV-Visible absorption peak for ZrO₂ was observed at 233 nm (5.3 eV in photon energy). The band at 363 nm for cubic ZrO₂ nanocrystals was found.     

The single source preparation of rod-like mercury sulfide nanostructures via hydrothermal method

High-quality and high-yield rod-like HgS dendrites with cubic structure was synthesized by a wet chemical route, without using any surfactant and organic solvents at 180 °C for 5 h, by using Hg(NO₃)₂·H₂O and thioglycolic acid (TGA) as starting reagents. The obtained HgS with different morphologies and sized were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). The effects of reaction parameters, such as temperature, precursor concentration and reaction time on the morphology and particle size of products were investigated. Our experimental results showed that temperature reaction played key role in the final morphology of HgS. The morphology of HgS nanostructures could be changed from rod-like dendrites to nanoparticles by only decreased temperature reaction to 110 °C. In the present study the possible mechanism of HgS nanoparticles growth to dendrites in the aqueous solution was also discussed and the optical properties rod-like HgS dendrites were investigated by ultraviolet-visible (UV-Vis) spectroscopy.     

Synthesis and characterization manganese oxide nanobundles from decomposition of manganese oxalate

The present investigation reports, the synthesis of manganese oxide (α-Mn₂O₃) nanobundles using thermal decomposition and its physicochemical characterization. The α-Mn₂O₃ nanobundles have been prepared using manganese oxalate dihydrate powders as precursor in the presence of oleylamine and triphenylphosphine as solvent and capping agent. Transmission electron microscopy (TEM) analysis demonstrated Mn₂O₃ nanobundles compose of nanospheres with diameter 30 nm. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy. Manganese oxide nanocrystals have been prepared under different condition. The controlled experimental results showed that the use of oleylamine and triphenylphosphine as the solvent and capping agent in the chemical process played important role in the formation of the final products.     

Synthesis and characterization of cobalt oxide nanoparticles by thermal treatment process

The simple preparation of Co₃O₄ nanoparticles from a solid organometallic molecular precursor N-N′-bis(salicylaldehyde)-1,2-phenylenediimino cobalt(II); Co(salophen) has been achieved via two simple steps: firstly, the Co(salophen) precursor was precipitated from the reaction of cobalt(II) acetate and N-N′-bis(salicylaldehyde)-1,2-phenylenediimino; H₂salophen; in propanol under nitrogen condition; then, cubic phase Co₃O₄ nanoparticles with the size of mostly 30-50 nm could be produced by thermal treatment of the Co(salophen) in air at 773 K for 5 h. The as-synthesized products were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and scanning electronic microscopy (SEM). These results confirm that the resulting oxide was pure single-crystalline Co₃O₄ nanoparticles. The optical property test indicates that the absorption peak of the nanoparticles shifts towards short wavelength, and the blue shift phenomenon might be ascribed to the quantum effect. The hysteresis loops of the obtained samples reveal the ferromagnetic behaviors the enhanced coercivity (H_c) and decreased saturation magnetization (M_s) in contrast to their respective bulk materials.     

Synthesis and characterization of nanocrystalline zinc sulfide via zinc thiobenzoate-lutidine single-source precursor

ZnS nanocrystals were prepared both in the form of mesoporous powder and thin films by one step thermal decomposition technique from a single-source procure (SSP) [Zn(SOCPh)₂Lut₂·H₂O]. The final product was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), N₂ adsorption-desorption isotherm, UV-Vis absorption spectroscopy and photoluminescence (PL) study. Structural analyses of the prepared ZnS revealed the formation of cubic crystallites with diameters around 5 and 10 nm for the thin films and powder materials, respectively. On the other hand, the powder form showed mesoporous nature (type IV isotherm) with an average pore diameter of 37.9 Å and BET specific surface area of 51.73 m²/g.     

Luminescent CeCl3 nanoparticles by Tris(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)cerium diglyme photolysis in chlorinated solvents

Irradiation of [Ce(hfac)₃(diglyme)] (hfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato and diglyme (DG) = 2,5,8,11,14-pentaoxapentadecane) in chlorinated solvents (CH₂Cl₂, CCl₄) with UV light led to luminescent colloidal CeCl₃ that was characterized by transmission electron microscopy (TEM) analysis. When a substrate, quartz or silicon was present in the reaction cell, photoluminescent films were obtained, containing either pure CeCl₃ or mixtures of CeCl₃, CeF₃ and CeOx in function of the experimental parameters of irradiation. Nanostructured and luminescent pure CeCl₃ films were obtained by irradiation of the cerium complex in CCl₄ at high intensity light for a few minutes. The films were characterized by X-ray diffraction (XRD), Energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), TEM, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The kinetics of the [Ce(hfac)₃(diglyme)] solution photodegradation, followed by UV spectrophotometry and spectrofluorimetry, pointed to CeCl₃ formation by a solvent-initiated reaction, whereas the other inorganic compounds were the products of side reactions.     

Preparation of NiO nanoparticles from metal-organic frameworks via a solid-state decomposition route

This study focuses on the preparation and characterization of single phase NiO nanoparticles. At first, nickel-o-phthalate complexes as precursor were synthesized through semisolid phase reaction method and then NiO nanoparticles were obtained via a solid-state decomposition procedure of layered coordination nickle-o-phthalate complexes formulated as [Ni(pht)(H₂O)₂] and [Ni(pht)₂]. In addition, the effects of calcination temperature and metal-to-ligand ratio on the particle size and morphology of NiO were investigated. Thermogravimetric analysis (TGA) was applied to determine the thermal behavior of complexes. The crystalline structure of products by X-ray diffractometer (XRD), morphology of particles by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were studied. The composition of as-prepared sample was studied by X-ray photoelectron spectroscopy (XPS) spectra. Analysis of FT-IR spectra confirmed the composition of products. The magnetic property was studied with vibrating sample magnetometer (VSM).     

Deposition of iron titanate/titania ceramic composite thin films from a single molecular precursor

A heterobimetallic single molecular precursor, [Fe₂Ti₄(μ-O)₆(TFA)₈(THF)₆] (1) [TFA = trifluoroacetate, THF = tetrahydrofuran], was synthesized by the simple reaction of [Fe₃O(OAc)₆(H₂O)₃]NO₃·4H₂O [OAc = acetato] with tetrakis(2-ethoxyethanalato)titanium(IV) in the presence of trifluoroacetic acid in THF. The synthesized precursor was analyzed by melting point, CHN analysis, FTIR, single crystal X-ray diffraction and thermogravimetric analysis. Complex (1) crystallizes in the orthorhombic space group Pca2₁ with cell dimensions a = 19.2114(14), b = 20.4804(15) and c = 17.2504(12) Å, and the complex undergoes thermal decomposition at 490 °C to give a residual mass corresponding to an Fe₂TiO₅-TiO₂ composite mixture. The synthesized precursor was utilized for deposition of Fe₂TiO₅-TiO₂ composite thin films by aerosol-assisted chemical vapor deposition (AACVD) on glass substrates at 500 °C using argon as the carrier gas. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray powder diffraction (XRD) analyses of the thin films suggest the formation of good quality crystalline thin films of an Fe₂TiO₅-TiO₂ composite with an average grain size of 0.105-0.120 μm.     

Synthesis of magnesium titanate nanocrystallites from a cheap and water-soluble single source precursor

Pure nanocrystallite magnesium titanate (MgTiO₃) was conveniently synthesized by thermal decomposition of a cheap and water-soluble heterobimetallic single source precursor [Mg(H₂O)₅]₂[Ti₂(O₂)₂O(NC₆H₆O₆)₂]·7H₂O at low temperature. This single source precursor was obtained in high yield and in a crystalline form from the quaternary system of MgO-Ti(OC₄H₉)₄-H₂O₂-H₃nta (H₃nta = nitrilotriacetic acid) at pH 4.0. It was characterized by elemental analysis, IR spectrum, NMR, thermal gravimetric analysis and X-ray single-crystal diffraction. The morphology, microstructure, and crystallinity of the resulting MgTiO₃ materials have been characterized by transmission electron microscopy and X-ray diffraction. The TEM image of the resulting MgTiO₃ powders only consists of the nano-scale crystallites with the crystalline size of 30-100 nm.     

First air stable tin(II) β-heteroarylalkenolate: Synthesis, characterization and application in chemical vapor deposition

A novel tin(II)-compound, bis(η²-N,O-2-[4,5-dimethyloxazolyl]-1,1,1-trifluoro-propen-2-olato)tin, Sn^II[(Me₂C₃NO)(CHCOCF₃)]₂ (1), was obtained by reacting Sn[N(SiMe₃)₂]₂ with 2 M equivalents of the β-heteroarylalkenol, (Me₂C₃NO)(CHCOHCF₃) (2). The molecular structures of ligand and the tin derivative were elucidated by single crystal X-ray diffraction and multi-nuclear NMR spectroscopic studies, which confirmed the monomeric nature and fourfold coordination of the tin(II) center with a pseudo-pyramidal geometry. The bidentate chelating mode of 2 imparted intriguingly high air stability to 1, which together with its high volatility make it an interesting precursor for the chemical vapor deposition (CVD) process. CVD of 1 on gold-coated Al₂O₃ substrates produced single crystalline SnO₂ nanowires by vapor-liquid-solid growth mechanism. Transmission electron microscopy studies and X-ray diffraction data confirmed the high crystallinity of SnO₂ nanowires possessing an average diameter of 90 nm.     

Sonochemical syntheses of strawberry-like nano-structure mixed-ligand lead(II) coordination polymer: Thermal, structural and X-ray powder diffraction studies

Nano-structure of a new Pb(II) two-dimensional coordination polymer, {[Pb(2-pyc)(N₃)(H₂O)]_n (1), 2-Hpyc = 2-pyridinecarboxylic acid} was synthesized by a sonochemical method. The new nano-structure was characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. Compound 1 was structurally characterized by single crystal X-ray diffraction and consists of two-dimensional polymeric units. The thermal stability of compound 1 was studied by thermal gravimetric and differential thermal analyses and compared. PbO nano-powder was obtained by calcination of the nano-structure of compound 1 at 400 °C. This study demonstrates the coordination polymers may be suitable precursors for the preparation of nano-scale materials and dependent on their packing they may produce different and interesting morphologies.     

A novel self-assembling of mixed tri- and dibutyltin macrocyclic complex with solvothermal synthesis method

The self-assembled reaction of 2-hydroxynicotinic acid, KOH and tri-n-butyltin chloride in CH₃OH and H₂O (V/V = 5:1) under solvothermal condition (150 °C) affords a novel mixed tri- and dibutyltin macrocyclic complex 1. Characterization of the complex 1 was achieved using elemental analysis, IR, NMR (¹H, ¹³C and ¹¹⁹Sn) spectroscopy, TGA and X-ray crystallography diffraction analysis. X-ray data revealed that it is an unusual 16-membered macrocycle containing eight tin atoms, and they can be divided into four sorts by the distinct environments, the endocyclic tin atoms are best described as five- and six-coordinate and the exocyclic tin atoms as five-coordinate. Furthermore, a 2D corrugated sheet is formed by intermolecular C-H?Cl, O-H?N and O-H?O weak interactions.     

Synthesis and characterization of one lead(II) photoluminescent coordination polymer with the fumarate ligand

One lead(II) coordination polymer, {[Pb(fum)(phen)]·2H₂O}_n (fum = fumarate, phen = 1,10-phenanthroline), was synthesized through the self-assembly of the lead(II) ion with the mixed fum and phen ligands and characterized by FT-IR spectroscopy, elemental analysis, thermogravimetric analysis, X-ray analysis and solid state photoluminescence spectrum. The compound shows a center-symmetrical dinuclear-based 2D architecture and further assembles into porous 3D supramolecular framework with 1D channel via interlayer π-π stacking interactions. The six-coordinated lead atoms in the complex show hemidirected geometry. The compound exhibits photoluminescence with the maximum emission located in UV region.     

Thermolysis preparation of zinc(II) oxide nanoparticles from a new micro-rods one-dimensional zinc(II) coordination polymer synthesized by ultrasonic method

The reaction of the zinc(II) acetate and 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene (3-bpdb) in presence of perchlorate anions produces a new one-dimensional coordination polymer, {[Zn(μ-3-bpdb)(3-bpdb)₂(H₂O)₂](ClO₄)₂·3-bpdb}_n (1). The compound 1 has been characterized by IR, ¹HNMR and ¹³CNMR spectroscopies. The single crystal X-ray data shows an infinite one-dimensional structure that grows in two- and three-dimensions by hydrogen bonding and π-π stacking. The compound 1 also has been synthesized at micro-size by sonochemical processes and characterized by IR and X-ray powder diffraction (XRD). The scanning electron microscopy (SEM) shows compound 1 has been grown as micro-rod morphology. The thermal stabilities at bulk and micro-size scale were studied by thermal gravimetric (TG) and differential thermal analysis (DTA). The ZnO nanoparticles were obtained by direct calcination at 400 °C under air atmosphere and by thermolysis in oleic acid at 200 °C. The obtained zinc(II) oxide nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).     

Synthesis and luminescent properties of gadolinium aluminates phosphors

In this work, aluminum-gadolinium oxides with different phases were prepared by the non-hydrolytic sol-gel route, using lower temperatures than those employed in methods such as solid-state reaction and Pechini method. The influence of heating treatment on sample structure was investigated. The formation process and the local structure of the samples are discussed on the basis of thermal, X-ray diffraction, photoluminescence (PL) spectroscopy, and infrared spectroscopy analyses. The quantum efficiency of Eu³⁺ in the different phases obtained in this studied was evaluated. Initial crystallization and the GdAlO₃ phase were observed at temperatures around 400 °C. PL data of all the samples revealed the characteristic transition bands arising from the ⁵D₀ → ⁵F_J (J = 0, 1, 2, 3, and 4) manifolds under maximum excitation at 275, 393, and 467 nm in all cases. The ⁵D₀ → ⁷F₂ transition often dominates the emission spectra, indicating that the Eu³⁺ ion occupies a site without inversion center.     

Nanopowders of 3D Ag coordination polymer: A new precursor for preparation of silver nanoparticles

Nanopowders of novel three-dimensional Ag^I coordination polymer, [Ag₂(μ₈-SB)]_n (1) [H₂SB = 4-[(4-hydroxyphenyl)sulfonyl]-1-benzenol] has been synthesized by the reaction of SB²⁻ and AgNO₃ by a sonochemical method. Reaction conditions, such as the concentration of the initial reagents and power of the ultrasonic device played important roles in the size, morphology and growth process of the final products. For the first time silver nanoparticles were synthesized from [Ag₂(μ₈-SB)]_n (1) coordination polymer by calcinations and hydrothermal methods. These nanopowders and nanoparticles were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM); transmission electron microscopy (TEM) and energy-dispersive X-ray spectra (EDS). Thermal stability and emission properties of nano and crystal samples of compound 1 were studied and compared with each other.     

A volatile Pb(II) β-Diketonate diglyme complex as a promising precursor for MOCVD of lead oxide films

A polyether adduct of the lead(II) hexafluoroacetylacetonate has been synthesized and characterized by elemental analysis, NMR spectroscopy, mass spectrometry and infrared spectroscopy. The single crystal X-ray diffraction study provides evidence of a dimeric structure of the type [Pb(hfa)₂ · diglyme]₂ (Hhfa=1,1,1,5,5,5-hexafluoro-2,4-pentanedione, diglyme=CH₃O(CH₂CH₂O)₂CH₃). The thermal analyses have revealed high volatility and good thermal stability with a low residue despite the dimeric nature of the adduct. This novel compound has been successfully applied as a precursor for the depositions of PbO films. It represents the first example of lead precursors that can be used in the liquid phase without decomposition, thus providing constant evaporation rates even for very long deposition times.     

Electrocatalytic activity of core/shell magnetic nanocomposite

Electrically active magnetic nanocomposites (EAMNCs), Au nanoparticles/self-doped polyaniline@Fe₃O₄ (AuNPs/SPAN@Fe₃O₄) with well-defined core/shell structure, were first synthesized by a simple method. The morphology and composition of the as-synthesized AuNPs/SPAN@Fe₃O₄ nanocomposite have been characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FT–IR), ultraviolet–visible (UV–Vis), X-ray powder diffraction (XRD), and thermogravimetric analysis (TGA). Horseradish peroxidase (HRP)–AuNPs/SPAN@Fe₃O₄ biocomposites were immobilized onto the surface of indium tin oxide (ITO) electrode to construct an amperometric hydrogen peroxide (H₂O₂) biosensor. The effects of HRP dosage, solution pH, and the working potential on the current response toward H₂O₂ reduction were optimized to obtain the maximal sensitivity. Under the optimal conditions, the proposed biosensor exhibited a linear calibration response in the range of 0.05 to 0.35 mM and 0.35 to 1.85 mM, with a detection limit of 0.01 mM (signal-to-noise ratio = 3). The modified electrode could virtually eliminate the interference of ascorbic acid (AA) and uric acid (UA) during the detection of H₂O₂. Furthermore, the biosensor was applied to detect H₂O₂ concentration in real samples, which showed acceptable accuracy with the traditional potassium permanganate titration.     

Hydrothermal synthesis and characterization of bismuth selenide nanorods via a co-reduction route

Bi₂Se₃ nanorods have been synthesized through a simple hydrothermal reduction approach. The nanorods formed were ≈50 nm in average diameter and ≈4 μm nm in length. XRD characterization suggested that the product consisted of the rhombohedral phase of pure Bi₂Se₃. The products were also characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermo gravimetric analysis. The synthesis procedure is simple and uses less toxic reagents than the previously reported methods. The results showed that the capping agent CTAB plays a crucial role in the process. Other factors, such as the reaction time, the different capping agent and the sort of reductant also have influence on the morphology of the final products to some extent.     

Development of silica-coated rare-earth doped strontium aluminate toward superhydrophobic,anti-corrosive and long-persistent photoluminescent epoxy coating

Long-persistent phosphorescent smart paints have the ability to continue glowing in the dark for a prolonged time period to function as energy-saving products. Herein, new epoxy/silica nanocomposite paints were prepared with different concentrations of lanthanide-doped aluminate nanoparticles (LAN; SrAl₂O₄:Eu²⁺,Dy³⁺). The LAN pigment was firstly coated with silicon dioxide (SiO₂) utilizing the heterogeneous precipitation technique to provide LAN-encapsulated between SiO₂ nanoparticles (LAN@SiO₂). The epoxy/silica/lanthanide-doped aluminate nanoparticles (ESLAN) nanocomposite paints were coated on steel. The prepared ESLAN paints were studied by transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray fluorescence (XRF) analysis, and energy-dispersive X-ray spectroscopy (EDS). The transparency and coloration properties of the nanocomposite coated films were explored by CIE Lab parameters and photoluminescence spectra. The ultraviolet-induced luminescence properties of the transparent coated films demonstrated greenish phosphorescence at 518 nm upon excitation at 368 nm. Both hardness and hydrophobic activities were investigated. The anticorrosion activity of the nanocomposite films coated onto mild steel substrates immersed in aqueous sodium chloride (NaCl_(aq)) (3.5%) was studied by electrochemical impedance spectroscopy (EIS). The silica-containing coatings were monitored to exhibit anticorrosion properties. Additionally, the nanocomposite films with LAN@SiO₂ (25%) exhibited the optimized long-lasting luminescence properties in the dark for 90 min. The nanocomposite films showed highly reversible and durable long-lived phosphorescence.