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Journal ArticleDOI

Decontamination and disinfection of water by solar photocatalysis: Recent overview and trends

15 Sep 2009-Catalysis Today (Elsevier)-Vol. 147, Iss: 1, pp 1-59
TL;DR: In this article, the authors reviewed the use of sunlight to produce the OH radicals by TiO2 photocatalysis and photo-Fenton process and summarized most of the research carried out related to solar photocatalytic degradation of water contaminants and how it could significantly contribute to the treatment of persistent toxic compounds.
About: This article is published in Catalysis Today.The article was published on 2009-09-15. It has received 2541 citations till now. The article focuses on the topics: Photocatalysis & Water treatment.
Citations
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Journal ArticleDOI
TL;DR: For the first time, a multi-variables optimization approach is described to determine the optimum operation parameters so as to enhance process performance and photooxidation efficiency in the photocatalytic water treatment process.

4,293 citations


Cites background from "Decontamination and disinfection of..."

  • ...These include Legionella pneumonphila and Cryptosporidium parvum oocysts (Malato et al., 2009)....

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  • ...The rate constant (kr) for most of the photocatalytic reaction in water is usually reported to be in the order of 106e109 (Ms) 1 (Malato et al., 2009)....

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  • ...In addition, the determination of photoreactor diameter is crucial in not only the effective photons absorption but also the water flow hydrodynamics (Malato et al., 2009)....

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  • ...The oxygen does not affect the adsorption on the TiO2 catalyst surface as the reduction reaction takes place at a different location from where oxidation occurs (Malato et al., 2009)....

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  • ...The TiO2 is the most active photocatalyst under the photon energy of 300 nm l 390 nm and remains stable after the repeated catalytic cycles, whereas Cds or GaP are degraded along to produce toxic products (Malato et al., 2009)....

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Journal ArticleDOI
TL;DR: In this paper, 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.
Abstract: 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.

3,305 citations

Journal ArticleDOI
TL;DR: In this paper, the fundamental mechanism of heterogeneous photocatalysis, advantages, challenges and the design considerations of g-C3N4-based photocatalysts are summarized, including their crystal structural, surface phisicochemical, stability, optical, adsorption, electrochemical, photoelectrochemical and electronic properties.

2,132 citations

Journal ArticleDOI
TL;DR: UV-Visible ار راد ن .د TiO2 ( تیفرظ راون مان هب نورتکلا یاراد لماش VB و ) رگید اب لاقتنا VB (CO2) .
Abstract: UV-Visible ار راد ن .د TiO2 ( تیفرظ راون مان هب نورتکلا یاراد یژرنا زارت لماش VB و ) رگید زارت ی یژرنا اب ( ییاناسر راون مان هب نورتکلا زا یلاخ و رتلااب VB یم ) .دشاب ت ود نیا نیب یژرنا توافت یژرنا فاکش زار ، پگ دناب هدیمان یم .دوش هک ینامز زا نورتکلا لاقتنا VB هب VB یم ماجنا دریگ ، TiO2 اب ودح یژرنا بذج د ev 2 / 3 ، نورتکلا تفج کی دیلوت یم هرفح .دیامن و نورتکلا هرفح ی نا اب هدش دیلوت یم کرتشم حطس هب لاقت ثعاب دناوت شنکاو ماجنا اه یی ددرگ . TiO2 دربراک ،دراد یدایز یاه هلمج زا یم ناوت اوه یگدولآ هیفصت یارب (CO2) و بآ و ... نآ زا هدافتسا درک .

2,055 citations

Journal ArticleDOI
TL;DR: The main conclusions arrived at from the overall assessment of the literature are that more work needs to be done on degradation kinetics and reactor modeling of the combined process, and also dynamics of the initial attack on primary contaminants and intermediate species generation.

2,046 citations


Cites background from "Decontamination and disinfection of..."

  • ...Such studies involve a considerable effort, dedication, and sophisticated analytical equipment (based on chromatography and mass spectrometry), but this is sometimes the only way to explain why acute toxicity arises during treatment, for example, by pinpointing a single intermediate degradation product that is more toxic than the original pollutant (Malato et al., 2009)....

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  • ...…analytical equipment (based on chromatography and mass spectrometry), but this is sometimes the only way to explain why acute toxicity arises during treatment, for example, by pinpointing a single intermediate degradation product that is more toxic than the original pollutant (Malato et al., 2009)....

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References
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Journal ArticleDOI
Ryoji Asahi1, Takeshi Morikawa1, T. Ohwaki1, Koyu Aoki1, Y. Taga1 
13 Jul 2001-Science
TL;DR: Film and powders of TiO2-x Nx have revealed an improvement over titanium dioxide (TiO2) under visible light in optical absorption and photocatalytic activity such as photodegradations of methylene blue and gaseous acetaldehyde and hydrophilicity of the film surface.
Abstract: 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.

11,402 citations

Journal ArticleDOI
20 Mar 2008-Nature
TL;DR: Some of the science and technology being developed to improve the disinfection and decontamination of water, as well as efforts to increase water supplies through the safe re-use of wastewater and efficient desalination of sea and brackish water are highlighted.
Abstract: One of the most pervasive problems afflicting people throughout the world is inadequate access to clean water and sanitation. Problems with water are expected to grow worse in the coming decades, with water scarcity occurring globally, even in regions currently considered water-rich. Addressing these problems calls out for a tremendous amount of research to be conducted to identify robust new methods of purifying water at lower cost and with less energy, while at the same time minimizing the use of chemicals and impact on the environment. Here we highlight some of the science and technology being developed to improve the disinfection and decontamination of water, as well as efforts to increase water supplies through the safe re-use of wastewater and efficient desalination of sea and brackish water.

6,967 citations

Journal ArticleDOI
TL;DR: A review of the current progress in the area of TiO 2 photocatalysis, mainly photocatalytic air purification, sterilization and cancer therapy is discussed in this paper.
Abstract: Scientific studies on photocatalysis started about two and a half decades ago. Titanium dioxide (TiO 2 ), which is one of the most basic materials in our daily life, has emerged as an excellent photocatalyst material for environmental purification. In this review, current progress in the area of TiO 2 photocatalysis, mainly photocatalytic air purification, sterilization and cancer therapy are discussed together with some fundamental aspects. A novel photoinduced superhydrophilic phenomenon involving TiO 2 and its applications are presented.

6,802 citations

01 Jan 2008
TL;DR: A review of the current progress in the area of TiO 2 photocatalysis, mainly photocatalytic air purification, sterilization and cancer therapy is discussed in this article.
Abstract: Abstract Scientific studies on photocatalysis started about two and a half decades ago. Titanium dioxide (TiO 2 ), which is one of the most basic materials in our daily life, has emerged as an excellent photocatalyst material for environmental purification. In this review, current progress in the area of TiO 2 photocatalysis, mainly photocatalytic air purification, sterilization and cancer therapy are discussed together with some fundamental aspects. A novel photoinduced superhydrophilic phenomenon involving TiO 2 and its applications are presented.

6,294 citations

Journal ArticleDOI
TL;DR: The field of photocatalysis can be traced back more than 80 years to early observations of the chalking of titania-based paints and to studies of the darkening of metal oxides in contact with organic compounds in sunlight as discussed by the authors.

5,729 citations