Indium doped zinc oxide nanopowders for transparent conducting coatings on glass substrates

Crystalline indium doped zinc oxide (IZO) nanopowders were synthesized using hydrothermal treatment processing. Increasing the doping ratio of indium in the zinc oxide significantly influences the phase structure and shape of the nanopowders resulting in nanorod to nanoparticulate morphologies. As the doping profile increases, the crystallite size decreases, the band gap energy blue shifts and the specific surface area increases (measured by BET method). Additionally Raman spectroscopy exhibited shifts of several peaks, as well as revealed new peaks, confirming the substitution of indium ions within the zinc oxide lattice sites. An IZO suspension made of IZO nanoparticles (In/Zn = 3 atm.%) with a zeta potential greater than 30 mV at pH = 6 was successfully spin-coated on glass substrates for to make transparent conductive coatings evincing sheet resistances as low as 35 kΩ_□ (ρ = 4.9 × 10^?3 Ω m,) with transmission in the visible range as high as 90 %.     

A facile route to fabricate stable reduced graphene oxide dispersions in various media and their transparent conductive thin films

Experimental data on the influence of the hydrothermal opening procedure conditions on the polarity, surface chemical composition and adsorption properties of multiwalled carbon nanotubes toward phenol are reported. The enthalpy of immersion measurements is reported, and it is shown that with the rise in burn-off, a progressive rise in nanotube surface polarity was observed. Using XPS data, the surface groups are identified. Moreover, by the analysis of HRTEM images and the values of enthalpy of immersion in benzene, it is shown that the removal of internal caps takes place mainly at higher burn-offs (larger than ca. 15%). Obtained series of nanotubes is tested in phenol adsorption, and calculated differential enthalpies of adsorption values are in the range of those determined for adsorption on graphite. Basing on obtained data, it is shown that the state of phenol in first layer is close to solid for adsorption on closed tubes and progressively approaches the state of supercooled liquid after tube opening and with the rise in burn-off.     

Aqueous solution route to high-aspect-ratio zinc oxide nanostructures on indium tin oxide substrates

High-aspect-ratio ZnO nanowires and nanotubes are formed on indium tin oxide (ITO) substrates using a three-step route at low temperatures. The three steps, including successive ionic layer absorption and reaction (SILAR) deposition of the ZnO seed layer, hydrothermal annealing of the seed layer, and chemical bath deposition (CBD) of the one-dimensional (1D) ZnO nanostructures, are all conducted in aqueous solutions at temperatures below 120 degrees C. Both the hydrothermal annealing of the SILAR seed layer and the low-concentration precursor solution employed in the CBD process are crucial in order to synthesize the uniform and high-aspect-ratio ZnO nanostructures on the ITO substrate. TEM analyses reveal that both the nanowire and the nanotube possess the single-crystal structure and are grown along [001] direction. Room-temperature cathodoluminescence spectrum of the 1D ZnO nanostructures shows a sharp ultraviolet emission at 375 nm and a broad green-band emission.     

Electrodeposition of zinc coatings from the solutions of zinc oxide in imidazolium chloride/urea mixtures

To solve the inherent disadvantages in conventional processes for electrodeposition of zinc, it’s necessary to develop more high-efficiency and environmentally friendly electrolytes. In this work, it was found that the dissolution of ZnO was remarkably enhanced in some imidazolium chloride by the addition of urea, and the solubility of ZnO in 1:1 [Amim]Cl/urea mixture was as high as 8.35 wt% at 373.2 K. Electrochemical measurements showed that zinc could be readily electrodeposited from the solutions of ZnO. Bright, dense and well adherent zinc coatings with good purity were obtained from 0.6 M solution of ZnO in 1:1 [Amim]Cl/urea at 323.2 343.2 K. It’s expected that the solutions of ZnO in imidazolium chloride/urea mixtures have the potential to replace the traditional electrolytes, especially toxic zinc chloride-based ones for zinc electroplating, as well as preparation of zinc materials.     

Preparation and properties of solution-processed zinc tin oxide films from a new organic precursor

Transparent,smooth and dense zinc tin oxide (ZTO) thin films have been successfully produced by using a new precursor solution,zinc acetate and tin(II) 2-ethylhexanoate mixed with 2-ethanolamine in methoxyethanol.The ZTO films have been prepared by spin-coating,followed by thermal treatment in oxygen atmosphere.The morphology,composition,crystallinity and band gap energy (Eg) of the ZTO thin films have been characterized by Atomic Force Microscopy (AFM),Atomic Emission Spectrometry (AES),X-ray Diffraction (...     

传感器用镓掺杂氧化锌纳米盘/纳米花状结构催化剂的制备及表面表征

采用简便的旋涂过程和一步水热法在压电基片上制备了Ga掺杂的ZnO纳米薄膜(GZO)。在水热处理过程中,通过添加不同的聚合物可形成纳米盘和纳米花状形貌的薄膜。采用场发射扫描电镜(Fe-SEM)、X射线衍射(XRD)和Raman光谱表征了样品的形貌、微结构和组成。 XRD和FE-SEM结果证明,在AlN/Si压电基片上形成的纳米盘、纳米棒和纳米花状GZO均为纤维锌矿相。采用浸渍法进一步在所制GZO样品上固定了绿色的荧光蛋白质(GFP)。运用原子力显微镜和荧光光谱分析了GFP与GZO表面结合的性质,考察了其用于传感器和生物成像技术的可行性。痕量GFP的固定使该材料产生荧光响应,表明其用于紫外光传感器时具有较好活性。     

Superhydrophobic and oleophobic coatings from flower-like zinc oxide and fluorinated epoxy with good comprehensive property

Nowadays, most superhydrophobic surfaces will lose their superhydrophobic performance once they encounter oil, and adhesive strength of superhydrophobic coating is low. Therefore, the superhydrophobic coating with good oleophobicity and high adhesive strength is popular with people. A superhydrophobic and oleophobic coating is characteristic of antifouling and self-cleaning, due to the appearance of special structures, such as overhang and re-entrant. In this work, flower-like zinc oxide (ZnO) particles free of fluorine and fluorine-containing epoxy were used to establish the coating with a similar re-entrant structure. Flower-like ZnO particles were prepared by a chemical precipitation method, and the water contact angle of flower-like ZnO is up to 149 ± 1°. For the coating, flower-like ZnO particles were almost covered by fluorine-containing epoxy synthesized through click reaction so that the adhesive strength between the coating and the matrix is high, superior to some coatings in the references. The surfaces made of flower-like ZnO and fluorinated epoxy possess superhydrophobic and oleophobic properties. The contact angle of the coating for water, diiodomethane, glycerol, and glycol is 154 ± 0.7°, 138 ± 0.6°, 156 ± 0.7°, and 150 ± 0.7°, respectively. After withstanding 70 cycles under the pressure of 1 kPa, the coating is still superhydrophobic. Also, the coating possesses a good self-cleaning and anti-icing property.     

A new route to antimony telluride nanoplates from a single-source precursor

Aerosol-assisted chemical vapor deposition (AACVD) of Sb[(TePiPr2)2N]3 results in pure hexagonal Sb2Te3 nanoplates between 375 and 475 degrees C on glass substrates, with a potential for enhanced thermoelectric properties for novel nanodevices.     

Chloro-free route to mixed-metal oxides. Synthesis of lead titanate nanoparticles from a single-source precursor route

A new heterobimetallic nitrilotriacetatoperoxotitanate complex of titanium and lead [Pb(H₂O)₃]₂[Ti₂(O₂)₂O(nta)₂]·4H₂O (C₆H₆O₆N=H₃nta) was isolated in pure crystals directly from the solution containing tetrabutyl orthotitanate, hydrogen peroxoide, lead acetate, and nitrilotriacetic acid at pH = 2.0–4.0. The isolated complex was characterized by elemental analyses, IR spectrum, thermal analysis (TG), and single-crystal X-ray diffraction. The single-crystal X-ray structural analysis revealed that the titanium atom is N,O,O′,O′′-chelated by the nitrilotriacetate and O,O′-chelated by the peroxo group and was coordinated to the bridging O atom in an overall pentagonal-bipyramidal geometry. The thermal decomposition of this precursor led to the formation of phase-pure lead titanate (PbTiO₃) at ≥450 °C. The morphology, microstructure, and crystalline of the resulting PbTiO₃ product have been characterized by BET, transmission electron microscopy, and powder X-ray diffraction. The TEM micrographs revealed that the size of the as-synthesized crystallines to be 50–100 nm range. The BET measurement revealed that the PbTiO₃ powders had a surface area of 5.6 m²/g.     

Induced zinc desorption from zinc oxide during exposure to a reducing agent

CH₃CH₂OD (deuterated ethanol) pulses (5 × 10^–4 ML, 20 ms) are offered to polycrystalline ZnO under ultra high vacuum conditions. The reaction products are monitored with a rate of 1000 spectra per second by a time of flight mass spectrometer. D₂O and CO₂, both including lattice oxygen, are observed in desorption. The creation of surface oxygen vacancies destabilizes zinc atoms nearby which appear also in desorption. The rate constant k_a (inverse relaxation time) increases below 900 K. Above this temperature k_a decreases. The decrease may be due to bulk oxygen diffusing to the surface and refilling the surface oxygen vacancies.     

MOCVD-derived highly transparent, conductive zinc- and tin-doped indium oxide thin films: precursor synthesis, metastable phase film growth and characterization, and application as anodes in polymer light-emitting diodes

Four diamine adducts of bis(hexafluoroacetylacetonato)zinc [Zn(hfa)(2).(diamine)] can be synthesized in a single-step reaction. Single crystal X-ray diffraction studies reveal monomeric, six-coordinate structures. The thermal stabilities and vapor phase transport properties of these new complexes are considerably greater than those of conventional solid zinc metal-organic chemical vapor deposition (MOCVD) precursors. One of the complexes in the series, bis(1,1,1,5,5,5-hexafluoro-2,4-pentadionato)(N,N'-diethylethylenediamine)zinc, is particularly effective in the growth of thin films of the transparent conducting oxide Zn-In-Sn-O (ZITO) because of its superior volatility and low melting point of 64 degrees C. ZITO thin films with In contents ranging from 40 to 70 cation % (a metastable phase) were grown by low-pressure MOCVD. These films exhibit conductivity as high as 2900 S/cm and optical transparency comparable to or greater than that of commercial Sn-doped indium oxide (ITO) films. ZITO films with the nominal composition of ZnIn(2.0)Sn(1.5)O(z)() were used in fabrication of polymer light-emitting diodes. These devices exhibit light outputs and current efficiencies almost 70% greater than those of ITO-based control devices.     

Synergistic flame-retardant and smoke suppression effects of zinc borate in transparent intumescent fire-retardant coatings applied on wood substrates

Journal of Thermal Analysis and Calorimetry - A series of novel phosphorus, boron, and zinc-containing flame retardants (ZPEAs) were synthesized by the esterification of cyclic phosphate ester with...     

Hydrothermal synthesis of zinc silicates from borosilicate glasses and from mixtures of zinc oxide and silica

The formation of sauconite and hemimorphite from glasses and oxide precursors in aqueous solution at 150–200°C is described. A tentative schematic stability diagram for a portion of the system Na₂O-ZnO-SiO₂-H₂O at 150°C is presented. The relevance of this work to the use of a sodium zinc borosilicate glass as a matrix for the immobilization of nuclear fuel reprocessing wastes is discussed briefly.     

Leaching of zinc and germanium from zinc oxide dust in sulfuric acid-ozone media

A new process of leaching zinc oxide dust by ozone oxidation in a sulfuric acid system was studied. The main factors affecting the leaching rate, such as ozone time, leaching temperature, initial acidity, leaching time, and liquid/solid mass ratio, were comprehensively investigated. The results show that leaching efficiency depends on all the above factors. The optimum conditions for leaching Zn and Ge from zinc oxide dust are as follows: ozone time 10 min, leaching temperature 90 ℃, initial acidity 160 g/L, leaching time 60 min, and liquid/solid mass ratio 7:1. Under the optimum conditions, the leaching rates of Zn and Ge are 95.79% and 93.65%, respectively. The leaching rates of zinc and germanium in the ozone leaching are 4.05% and 10.49% higher than those of the atmospheric leaching, respectively. Therefore, it is determined that ozone in solution plays a key role in rapidly oxidizing sulfide and releasing encapsulated germanium. Sulfuric acid-ozone media can efficiently extract Zn and Ge from zinc oxide dust.     

Indium oxide co-doped with tin and zinc: A simple route to highly conducting high density targets for TCO thin-film fabrication

Indium oxide co-doped with tin and zinc (ITZO) ceramics have been successfully prepared by direct sintering of the powders mixture at 1300 °C. This allowed us to easily fabricate large highly dense target suitable for sputtering transparent conducting oxide (TCO) films, without using any cold or hot pressing techniques. Hence, the optimized ITZO ceramic reaches a high relative bulk density (∼ 92% of In₂O₃ theoretical density) and higher than the well-known indium oxide doped with tin (ITO) prepared under similar conditions. All X-ray diagrams obtained for ITZO ceramics confirms a bixbyte structure typical for In₂O₃ only. This indicates a higher solubility limit of Sn and Zn when they are co-doped into In₂O₃ forming a solid-solution. A very low value of electrical resistivity is obtained for [In₂O₃:Sn_0.10]:Zn_0.10 (1.7 × 10⁻³ Ω cm, lower than ITO counterpart) which could be fabricated to high dense ceramic target suing pressure-less sintering.     

Zn2+ release from zinc and zinc oxide particles in simulated uterine solution

Zn²⁺ release from Zn and ZnO particles with different sizes in simulated uterine solution were investigated by absorbance measurements. The effects of pH and human serum albumin (HSA) on Zn²⁺ release were also studied. The morphology of Zn and ZnO particles was observed by scanning electron microscopy, and the corrosion products of zinc nanoparticles were analyzed by XRD. The results indicate that the maximum release ratios of Zn²⁺ from Zn and ZnO nanoparticles are higher than those from Zn and ZnO microparticles. Zn²⁺ release ratio depends not only on the pH of the simulated uterine solution but also the presence of human serum albumin. It decreases as the pH of the uterine solution increases. The trends of Zn²⁺ release ratios are almost the opposite for solutions with and without HSA. XRD analysis results indicate that zinc oxide is the main corrosion product of zinc particles.     

Preparation of nitrogen doped zinc oxide nanoparticles and thin films by colloidal route and low temperature nitridation process

Nitrogen doped zinc oxide (ZnO) nanoparticles have been synthesized using a colloidal route and low temperature nitridation process. Based on these results, 200 nm thick transparent ZnO thin films have been prepared by dip-coating on SiO₂ substrate from a ZnO colloidal solution. Zinc peroxide (ZnO₂) thin film was then obtained after the chemical conversion of a ZnO colloidal thin film by H₂O₂ solution. Finally, a nitrogen doped ZnO nanocrystalline thin film (ZnO:N) was obtained by ammonolysis at 250 °C. All the films have been characterized by scanning electron microscopy, X-ray diffraction, X-Ray photoelectron spectroscopy and UV–Visible transmittance spectroscopy.