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

A 16 × 16 monolithic pyroelectric infrared image sensor has been developed. The image sensor utilizes an electro-spray (ESP)-deposited polyvinylidene fluoride (PVDF) thin film as a pyroelectric material, a buried-channel MOSFET as a low-noise detection device, and a micromachined membrane supported by four beams as a thermal isolation structure. A voltage sensitivity of 6600 V W −1 and a detectivity of 1.6 × 10 7 cm Hz 1/2 W −1 have been realized with a sensing area of 75 μm × 75 μm.

Monolithic pyroelectric infrared image sensor using PVDF thin film

An organic electroluminescent device includes an anode, a cathode, a hole injection layer, a hole transport layer, an electron capture layer, a luminescent layer, and an electron transport layer. The five layers are sequentially stuck in the above order between the anode and the cathode in the direction toward the cathode. The luminescent layer includes a host organic material, the luminescent spectrum of which has a peak between 380 nm and 510 nm, and a guest fluorescent dye. The hole injection layer and the hole transport layer respectively include a host organic material. The lowest energy level in the conduction band of the host organic material of the electron capture layer is lower than those of the hole transport layer and the luminescent layer. Therefore, the device can emit light including blue light component while the host organic material of the hole transport layer is prevented from deteriorating.

Organic electroluminescent device

An infrared shielding lamination comprises alternate infrared shield layers and interferential reflection layers. These layers have good transparency to visible light and the infrared shield layers are able to prevent the transmission of the infrared rays. The interferential reflection layers along with adjacent infrared shield layers cause an interferential reflection effect on the wavelengths in the near-infrared spectrum, thus preventing the transmission of near-infrared rays. When a composite lamination according to this invention is applied to a glass plate or other plate transparent to visible light, the so-treated plate will exclude infrared and near-infrared rays without impairing the transparency of the plate to visible light.

Infrared shielding lamination

We have demonstrated the integration of various morphologies generated by dynamic oblique deposition, during which the deposition angle and the azimuth of the substrate are varied. The layers with zigzag, helicoidal and cylindrical columns have been successfully stacked on a substrate without using any etching process. In addition, the uniform and flat layer is formed on porous layers by a gradual change in the deposition geometry. Therefore, shape-related physical anisotropies and the chemical activity due to high porosity can be integrated in one thin film, making it applicable to devices such as solar cells and chemical sensors.

Integrated Sculptured Thin Films

A heat wave shielding lamination having improved abrasion resistance is composed of a visible light transparent substrate and an overlying composite lamination in which layers of a visible light transparent substance of a low refractive index and layers of a visible light transparent substance of a high refractive index are alternately arranged on each other, with the topmost layer being a low-refractance layer, and interfacial layers of Al2 O3 which are much thinner than the high-refractance and low-refractance layers are provided between the high-refractance and low-refractance layers.

Yasunori Taga

Papers

Monolithic pyroelectric infrared image sensor using PVDF thin film

Organic electroluminescent device

Infrared shielding lamination

Integrated Sculptured Thin Films

Heat wave shielding lamination