Formation Characteristics of Pt-Ni Alloy Nanoparticles Fabricated by Nanolamination of Atomic Layer Deposition in Hydrogen.

Forced-flow atomic layer deposition nanolamination is employed to fabricate Pt-Ni nanoparticles on XC-72, with the compositions ranging from PtNi to PtNi. Hydrogen is used as a co-reactant for depositing Pt and Ni. The growth rate of Pt is slower than that using oxygen reactant, and the growth exhibits preferred orientation along the (111) plane.

Thermal Degradation of Vegetable Oils.

Vegetable oils provide lipids and nutrition and provide foods with a desirable flavor, color, and crispy texture when used to prepare fried foods. However, the oil quality is degraded at elevated temperatures, and thus must be examined frequently because of the damage to human health. In this study, sunflower, soybean, olive, and canola oils were examined, and their properties were measured periodically at different elevated temperatures.

Formation Mechanism and Bandgap Reduction of GaN-ZnO Solid-Solution Thin Films Fabricated by Nanolamination of Atomic Layer Deposition.

Nanolamination of GaN and ZnO layers by atomic layer deposition (ALD) is employed to fabricate GaN-ZnO homogenous solid-solution thin films because it offers more precise control of the stoichiometry. By varying the ALD cycle ratios of GaN:ZnO from 5:10 to 10:5, the (GaN) (ZnO) films with 0.39 ≦ x ≦ 0.

Forced flow atomic layer deposition of TiO on vertically aligned Si wafer and polysulfone fiber: Design and efficacy of conduit plates and soak function.

The effectiveness of three different designs of conduit plates was verified for even distribution of precursors in a voluminous forced-flow atomic layer deposition (ALD) chamber designed to hold macroscopic elongated substrates vertically. Furthermore, a new "soak function" was introduced in the controlling software of the ALD instrument. This function enabled increase in residence time of the precursor in the chamber without escalating the dosage.

Photocatalysis and Hydrogen Evolution of Al- and Zn-Doped TiO Nanotubes Fabricated by Atomic Layer Deposition.

Highly homogeneous Al- and Zn-doped TiO nanotubes were fabricated by atomic layer deposition (ALD) via nanolaminated stacks of binary layers of TiO/AlO and TiO/ZnO, respectively. The bilayers were alternately deposited on the polycarbonate (PC) membrane template by ALD with various cyclic sequences. The nanotubes in a length of 20 μm and a diameter of 220 nm were obtained after removal of the PC membrane by annealing at 450 °C.

Fabrication of TiO on porous g-CN by ALD for improved solar-driven hydrogen evolution.

Porous graphitic carbon nitride (P-g-CN) thin sheets were fabricated by a one-step calcination of a mixture of urea, melamine, and ammonia chloride at 550 °C. P-g-CN showed 48% higher photocatalytic H production from methanol aqueous solution than conventional urea-derived graphitic carbon nitride (g-CN) because the existence of numerous pores reduces the recombination rate of charge carriers. In order to further enhance the photocatalytic activity, TiO was uniformly deposited on P-g-CN by 60-300 cycles of atomic layer deposition (ALD) to form the TiO@P-g-CN composite.

Uniform coating of TaO on vertically aligned substrate: A prelude to forced flow atomic layer deposition.

Uniform tantalum oxide thin films, with a growth rate of 0.6 Å/cycle, were fabricated on vertically aligned, 10 cm-long, silicon substrates using an innovative atomic layer deposition (ALD) design. The ALD system, with a reaction chamber depth of 13.

Direct formation of anatase TiO2 nanoparticles on carbon nanotubes by atomic layer deposition and their photocatalytic properties.

TiO2 with different morphology was deposited on acid-treated multi-walled carbon nanotubes (CNTs) by atomic layer deposition at 100 °C-300 °C to form a TiO2@CNT structure. The TiO2 fabricated at 100 °C was an amorphous film, but became crystalline anatase nanoparticles when fabricated at 200 °C and 300 °C. The saturation growth rates of TiO2 nanoparticles at 300 °C were about 1.

Distribution pattern and allocation of defects in hydrogenated ZnO thin films.

A polycrystalline ZnO thin film prepared by atomic layer deposition was annealed in hydrogen at 10 bar and 350-450 °C. Hydrogenation induced simultaneous formation of oxygen and zinc vacancies whose concentrations were closely related to the temperature of treatment. Spatial distributions of these defects were analyzed by photoluminescence confocal mapping which revealed that their localized appearances are linked to each other.

Enabling higher photoelectrochemical efficiency of TiO2via controlled formation of a disordered shell: an alternative to the hydrogenation process.

A simple one-step and low-temperature process was developed to form an amorphous overlayer on the crystalline TiO2 film by atomic layer deposition. This composite structure is beneficial for improved photoelectrochemical efficiency since the as-deposited amorphous layer showed unique properties such as local disorder and presence of oxygen vacancies.

Enabling high solubility of ZnO in TiO₂ by nanolamination of atomic layer deposition.

Zn-doped TiO2 nanotubes were fabricated by nanolaminated packing of alternating layers of TiO2 and ZnO by atomic layer deposition (ALD) using a polycarbonate (PC) membrane as a template. With 400 cycles of ALD, the nanotubes with a thickness of 28 nm and an outer diameter of 220 nm were obtained after removing the PC membrane by annealing at 450 °C. The doping concentration of ZnO in TiO2 depends on the precursor cycle ratio of ZnO to TiO2.

Extremely high efficient nanoreactor with Au@ZnO catalyst for photocatalysis.

We fabricated a photocatalytic Au@ZnO@PC (polycarbonate) nanoreactor composed of monolayered Au nanoparticles chemisorbed on conformal ZnO nanochannel arrays within the PC membrane. A commercial PC membrane was used as the template for deposition of a ZnO shell into the pores by atomic layer deposition (ALD). Thioctic acid (TA) with sufficient steric stabilization was used as a molecular linker for functionalization of Au nanoparticles in a diameter of 10 nm.

HNO₃-assisted polyol synthesis of ultralarge single-crystalline Ag microplates and their far propagation length of surface plasmon polariton.

We developed a HNO3-assisted polyol reduction method to synthesize ultralarge single-crystalline Ag microplates routinely. The edge length of the synthesized Ag microplates reaches 50 μm, and their top facets are (111). The mechanism for dramatically enlarging single-crystalline Ag structure stems from a series of competitive anisotropic growths, primarily governed by carefully tuning the adsorption of Ag(0) by ethylene glycol and the desorption of Ag(0) by a cyanide ion on Ag(100).

Deposition of platinum on oxygen plasma treated carbon nanotubes by atomic layer deposition.

Platinum nanoparticles were deposited on oxygen plasma treated carbon nanotubes (CNTs) by atomic layer deposition (ALD). The treatment time with oxygen plasma generated by microwaves under a power of 600 W varied from 5 to 20 s. The number of ALD cycles was controlled at 5-125.

Preparation and characterization of molecularly homogeneous silica-titania film by sol-gel process with different synthetic strategies.

Three silica-titania thin films with various degrees of molecular homogeneity were synthesized by the sol-gel process with the same precursor formula but different reaction paths. The dried films prepared by a single spin-coating process have a thickness of 500-700 nm and displayed no cracks or pin holes. The transmittances and refractive indices of the samples are >97.

Fabrication of TiO2 nanotubes by atomic layer deposition and their photocatalytic and photoelectrochemical applications.

The formation of TiO(2) nanotubes was conducted by atomic layer deposition (ALD) with tris-(8-hydroxyquinoline) gallium (GaQ(3)) nanowires as a template at different substrate temperatures, 50, 100, and 200 °C. TiO(2) nanotubes were formed only at 50 and 100 °C. Although a higher growth rate at 50 °C was observed, nanotubes with better uniformity, conformality, and less residual chloride were obtained at 100 °C because of a different formation mechanism.

Photocatalytic degradation of rhodamine B by anchored TiO2 nanowires.

Rutile TiO2 nanowires anchored on silica were fabricated by annealing TiO2 nanoparticles dispersed on silicon or quartz substrate by means of a polystyrene nanosphere monolayer template at 1000 degrees C for 1 h without any catalyst. The diameter and length of the nanowires were 30-80 nm and 1-3 microm, respectively. The growth direction of the nanowires is [112].

The formation of TiO(2) nanowires directly from nanoparticles.

TiO(2) nanowires were fabricated by annealing TiO(2) nanoparticles on silicon substrate at 1000 degrees C in air. When a polystyrene nanosphere monolayer was used as a template to separate the TiO(2) nanoparticles, they could more easily react with the silicon substrate to form Ti(5)Si(3). The TiO(2) nanowires were formed upon further oxidation of Ti(5)Si(3).

Comparison of organic and inorganic germanium compounds in cellular radiosensitivity and preparation of germanium nanoparticles as a radiosensitizer.

Purpose: The aim of this work is to compare the radiosensitizing effect between organic and inorganic germanium compounds and to investigate whether nanometer-sized germanium particles can act as radiosensitizers.

Materials And Methods: Bis (2-carboxyethylgermanium) sesquioxide (Ge-132), germanium oxide (GeO(2)) and germanium nanoparticles were used in this study. Cell viability was determined by clonogenic survival assay.

Synthesis and photoluminescence of amorphous Ca5Ge2O9 nanowires.

A new method to prepare amorphous Ca5Ge2O9 nanowires is demonstrated in the present study. Germanium nanoparticles with the size ranging from 10 to 50 nm were first prepared by a vapor condensation technique. Upon immersing the nanoparticles in Ca(OH)2 aqueous solution, hydrated Ca5Ge2O9 nanowires were formed rapidly.

Crystalline Gaq(3) Nanostructures: Preparation, Thermal Property and Spectroscopy Characterization.

Crystalline Gaq(3) 1-D nanostructures and nanospheres could be fabricated by thermal evaporation under cold trap. The influences of the key process parameters on formation of the nanostructures were also investigated. It has been demonstrated that the morphology and dimension of the nanostructures were mainly controlled by working temperature and working pressure.

The passive optical properties of a silicon nanoparticle-embedded benzocyclobutene polymer waveguide.

The passive optical properties of a silicon nanoparticle-embedded benzocyclobutene (BCB) waveguide were investigated. The silicon nanoparticles, of a size varying from 6 to 25 nm, were prepared by vapor condensation. The transmission modes and losses were examined by the prism coupler and cut-back methods.