To use solar irradiation or interior lighting efficiently, we sought a photocatalyst with high reactivity under visible light. Films and powders of TiO 2- x N x have revealed an improvement over titanium dioxide (TiO 2 ) under visible light (wavelength 2 has proven to be indispensable for band-gap narrowing and photocatalytic activity, as assessed by first-principles calculations and x-ray photoemission spectroscopy.

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Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

[Yang, Hua Gui; Sun, Cheng Hua; Qiao, Shi Zhang; Liu, Gang; Smith, Sean Campbell; Lu, Gao Qing] Univ Queensland, ARC Ctr Excellence Funct Nanomat, Sch Engn, Brisbane, Qld 4072, Australia. [Yang, Hua Gui; Sun, Cheng Hua; Qiao, Shi Zhang; Liu, Gang; Smith, Sean Campbell; Lu, Gao Qing] Univ Queensland, Australian Inst Bioengn & Nanotechnol, Ctr Computat Mol Sci, Brisbane, Qld 4072, Australia. [Zou, Jin] Univ Queensland, Ctr Microscopy & Microanal, Brisbane, Qld 4072, Australia. [Zou, Jin] Univ Queensland, Sch Engn, Brisbane, Qld 4072, Australia. [Liu, Gang; Cheng, Hui Ming] Chinese Acad Sci, Met Res Inst, Shenyang Natl Lab Mat sci, Shenyang 110016, Peoples R China.;Lu, GQ (reprint author), Univ Queensland, ARC Ctr Excellence Funct Nanomat, Sch Engn, Brisbane, Qld 4072, Australia;s.qiao@uq.edu.au maxlu@uq.edu.au

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Anatase TiO(2) single crystals with a large percentage of reactive facets

Fujishima and Honda (1972) demonstrated the potential of titanium dioxide (TiO2) semiconductor materials to split water into hydrogen and oxygen in a photo-electrochemical cell. Their work triggered the development of semiconductor photocatalysis for a wide range of environmental and energy applications. One of the most significant scientific and commercial advances to date has been the development of visible light active (VLA) TiO2 photocatalytic materials. In this review, a background on TiO2 structure, properties and electronic properties in photocatalysis is presented. The development of different strategies to modify TiO2 for the utilization of visible light, including non metal and/or metal doping, dye sensitization and coupling semiconductors are discussed. Emphasis is given to the origin of visible light absorption and the reactive oxygen species generated, deduced by physicochemical and photoelectrochemical methods. Various applications of VLA TiO2, in terms of environmental remediation and in particular water treatment, disinfection and air purification, are illustrated. Comprehensive studies on the photocatalytic degradation of contaminants of emerging concern, including endocrine disrupting compounds, pharmaceuticals, pesticides, cyanotoxins and volatile organic compounds, with VLA TiO2 are discussed and compared to conventional UV-activated TiO2 nanomaterials. Recent advances in bacterial disinfection using VLA TiO2 are also reviewed. Issues concerning test protocols for real visible light activity and photocatalytic efficiencies with different light sources have been highlighted.

/pdf/a-review-on-the-visible-light-active-titanium-dioxide-2qg81s4yao.pdf

A review on the visible light active titanium dioxide photocatalysts for environmental applications

We demonstrate very high efficiency electrophosphorescence in organic light-emitting devices employing a phosphorescent molecule doped into a wide energy gap host. Using bis(2-phenylpyridine)iridium(III) acetylacetonate [(ppy)2Ir(acac)] doped into 3-phenyl-4(1′-naphthyl)-5-phenyl-1,2,4-triazole, a maximum external quantum efficiency of (19.0±1.0)% and luminous power efficiency of (60±5) lm/W are achieved. The calculated internal quantum efficiency of (87±7)% is supported by the observed absence of thermally activated nonradiative loss in the photoluminescent efficiency of (ppy)2Ir(acac). Thus, very high external quantum efficiencies are due to the nearly 100% internal phosphorescence efficiency of (ppy)2Ir(acac) coupled with balanced hole and electron injection, and triplet exciton confinement within the light-emitting layer.

Nearly 100% internal phosphorescence efficiency in an organic light emitting device

We sputter-deposited oxide thin films such as Y2O3, SiO2, TiO2, Ta2O5, CeO2, and MoO3 and studied water droplet wettability and the surface friction coefficient under the controlled conditions of 20-25°C and 50-60% RH. Water droplet wettability was evaluated by measuring the contact angle. We found that the angle increased and saturated over time for all tested oxide thin films and that contact angle saturation depended on the type of oxide thin films used. The relationship between the contact angle and r/Z (ion radius divided by cation charge) suggests that the oxide surface structure affects adsorption states. We also found that the thin film surface friction coefficient also decreased over time in line with variations in the contact angle. The correspondence between the friction coefficient and adhesion derived from the contact angle means that friction originates in adhesive force.

https://www.jstage.jst.go.jp/article/sfj1989/49/2/49_2_191/_pdf

Wettability and Friction Coefficient of the Oxide Thin Film Surface

The damage layer of a Si(100) surface induced by low-energy (300–600 eV) rare-gas (Ne, Ar, or Xe) ion bombardment was in situ analyzed by x-ray photoelectron spectroscopy (XPS). The XPS analysis showed that, irrespective of the ionic species, an amorphous Si (a-Si) layer with a thickness of 10–30 A was formed and saturated by the dose of 1015 cm−2. It also showed that the thickness increased linearly with the ion energy and Ne ions formed the thickest a-Si layer. The saturated thickness measured with the XPS analysis has been confirmed by cross-sectional transmission electron microscopy. Formation process of the a-Si layer under small dose of ions can be explained in terms of the Poisson process. As a result, the size of an a-Si region formed by single ion bombardment was estimated. The region, which is supposed to have a cylindrical shape, has a radius of 2–4 A and a height of 10–30 A for each ionic species and energy. In situ XPS analysis for the Si surface bombarded with ion beams revealed the growth p...

In situ analysis of Si(100) surface damage induced by low-energy rare-gas ion bombardment using x-ray photoelectron spectroscopy

PROBLEM TO BE SOLVED: To provide a ferromagnetic spin tunnel effect element having a large rate of change in resistance. SOLUTION: A first ferromagnetic body 12 and a second ferromagnetic body 14 are oppositely located via an insulation layer 13 in a ferromagnetic spin tunnel effect element where a tunnel current flowing through the insulation layer 13 changes, depending on the relation of magnetization direction between the first ferromagnetic body 12 and the second ferromagnetic body 14, the first ferromagnetic body 12 or/and second ferromagnetic body 14 are made of a ferromagnetic semimetal. As a result, the rate of change in resistance becomes much greater than that of the conventional ferromagnetic spin tunnel effect element.

Ferromagnetic spin tunnel effect element

PURPOSE: To provide an organic electroluminescent element that is thermally stable, can hold its emission performance at a predetermined level or higher over a long time, and is excellent in durability. CONSTITUTION: An anode 12 is formed over a substrate 10, an emitter layer 14 is formed over the anode 12, and a carthode 16 is formed over the emitter layer 14. The emitter layer 14 is composed of composite thin films comprising an organic compound 22 uniformly dispersed in an inorganic compound 24, so as to enhance the thermal stability and durability of an element.

Orfanic/inorganic complex thin-film electroluminescent element

PURPOSE:To improve the characteristic of a thin film by depositing a metal and metallic oxide by sputtering on the body to be vapor deposited then irradiating ion the vapor deposition part with ion beams to implant desired ions therein and controlling discretely and independently the vapor deposition by sputtering and the ion beam irradiation. CONSTITUTION:A sputtering device 18 is constituted of a magnetron sputtering source 22 and a sputtering target 24, and a metal and metallic oxide are deposited by sputtering on the body to be vapor deposited 12 from a sputtering target 24 by feeding RF or DC electric power to the source 22. On the other hand, an ion beam irradiation device 20 has an ion source 26, an ion passage pipe 28, and an ion draw-out electrode 30. The ions drawn from an ion source 26 are accelerated, scanned and controlled by means of an ion beam accelerating electrode 32 and an ion beam deflector 36, by which the ion beam is irradiated to the prescribed position of the body 12. The deposition by sputtering, the deposition by evaporation and the ion beam irradiation are discretely and independently controlled.

Yasunori Taga

Papers

Wettability and Friction Coefficient of the Oxide Thin Film Surface

In situ analysis of Si(100) surface damage induced by low-energy rare-gas ion bombardment using x-ray photoelectron spectroscopy

Ferromagnetic spin tunnel effect element

Orfanic/inorganic complex thin-film electroluminescent element

Method and device for coating thin metallic film by vapor deposition