다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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.

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

A review on g-C3N4-based photocatalysts

Advanced oxidation processes (AOPs) constitute important, promising, efficient, and environmental-friendly methods developed to principally remove persistent organic pollutants (POPs) from waters and wastewaters. Generally, AOPs are based on the in situ generation of a powerful oxidizing agent, such as hydroxyl radicals (•OH), obtained at a sufficient concentration to effectively decontaminate waters. This critical review presents a precise and overall description of the recent literature (period 1990–2012) concerning the main types of AOPs, based on chemical, photochemical, sonochemical, and electrochemical reactions. The principles, performances, advantages, drawbacks, and applications of these AOPs to the degradation and destruction of POPs in aquatic media and to the treatment of waters and waste waters have been reported and compared.

Advanced Oxidation Processes in Water/Wastewater Treatment: Principles and Applications. A Review

Nitrogen-doped titanium dioxide as visible-light-sensitive photocatalyst: designs, developments, and prospects.

Among the three major phases in titania, anatase is reported to be a better photocatalytically active phase. Anatase to rutile transformations, under normal conditions, usually occurs at a temperatue range of 600−700 °C. Various chemical additives have previously been employed to extend the anatase transition to higher temperatures. The effect of employing various concentrations of formic acid and water on phase transition has systematically been studied by XRD, FTIR, and Raman spectroscopy. A considerably higher anatase phase (41%) has been obtained at 800 °C, and 10% anatase composition is retained after annealing the materials at 900 °C for the optimized composition. On comparison, a control sample which has been prepared without formic acid showed that the rutile phase formed at a temperature of 600 °C, FTIR and Raman studies indicated that the formate group favored a bridging (syn−anti or syn−syn) mode of chelation depending on the reaction conditions. It has been concluded that the resulting syn−ant...

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Spectroscopic Investigation of the Anatase-to-Rutile Transformation of Sol−Gel-Synthesized TiO2 Photocatalysts

https://arrow.tudublin.ie/cgi/viewcontent.cgi?article=1016&context=cenresart

Effect of N-doping on the photocatalytic activity of sol-gel TiO2

The synthesis of a ZnO−TiO2 nanocomposite usually results in the formation of one or more of three compounds—Zn2TiO4, Zn2Ti3O8, and ZnTiO3—along with other secondary impurity phases, such as rutile-TiO2 or ZnO. Obtaining a phase-pure composite of either of these materials is one of the challenges in materials chemistry. For example, pure ZnTiO3 cannot be synthesized under normal conditions, because the ZnTiO3 phase readily transforms to Zn2TiO4 and rutile. Zn2Ti3O8 is reported as a metastable form of ZnTiO3. The Zn2TiO4 form is usually synthesized via solid-state reaction at high temperatures (typically above 1000 °C). In the current study, the crystalline and phase-transformation behaviors of sol−gel-synthesized zinc titanates has been investigated systematically, with regard to various Zn:Ti precursor molar ratios. X-ray diffraction (XRD) has shown that, with excess titanium precursor, zinc metatitanate (ZnTiO3) is the preferred zinc titanate phase formed at temperatures of 600−900 °C, with a direct tra...

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Crystallization and Phase-Transition Characteristics of Sol−Gel-Synthesized Zinc Titanates

Anatase to rutile transformation in an unmodified synthetic titania usually occurs at a temperature range of 600−700 °C Various methods such as addition of metallic and nonmetallic dopants and modifying the precursor have previously been reported to influence the anatase to rutile transformation temperature In the current study, the effect of addition of increasing amounts of silver on the extent of chelation of a formate group to a titanium precursor and the resulting effects on the transformation of anatase to rutile has been studied The addition of silver (0, 1, 3, and 5 mol %) on the anatase to rutile transformation temperature has been systematically followed by Fourier transform infrared (FTIR), Raman, X-ray diffraction (XRD), differential scanning calorimetry, and X-ray photoelectron spectroscopy (XPS) studies From the FTIR and Raman spectroscopy studies it was observed that the incorporation of silver caused a reduction in the intensity of the COO− stretches indicating that the titania formate

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A Systematic Study of the Effect of Silver on the Chelation of Formic Acid to a Titanium Precursor and the Resulting Effect on the Anatase to Rutile Transformation of TiO2

Nicholas T. Nolan

Papers

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

Spectroscopic Investigation of the Anatase-to-Rutile Transformation of Sol−Gel-Synthesized TiO2 Photocatalysts

Effect of N-doping on the photocatalytic activity of sol-gel TiO2

Crystallization and Phase-Transition Characteristics of Sol−Gel-Synthesized Zinc Titanates

A Systematic Study of the Effect of Silver on the Chelation of Formic Acid to a Titanium Precursor and the Resulting Effect on the Anatase to Rutile Transformation of TiO2