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Atsunori Matsuda - One of the best experts on this subject based on the ideXlab platform.
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pHotoluminescence properties of rod like ce doped zno nanostructured films formed by Hot Water Treatment of sol gel derived coating
Optical Materials, 2013Co-Authors: Wai Kian Tan, Khairunisak Abdul Razak, Zainovia Lockman, Go Kawamura, Hiroyuki Muto, Atsunori MatsudaAbstract:Abstract Rod-like undoped and Ce-doped ZnO nanostructures have been formed using Hot-Water Treatment of the undoped and Ce-doped sol–gel derived layer at low temperature of 60 °C for 30 min on glass substrates. The concentration of Ce doping was varied from 2 to 20 at% in the precursor films. Morphological structures and optical properties of the Hot-Water treated ZnO films were investigated and compared with those of the conventional, annealed ZnO films. The resultant undoped and Ce-doped rod-like ZnO films showed ultraviolet (UV) and strong blue emissions. The pHotoluminescence of the Ce-doped films exhibited blue shift in UV emission and reduced blue emission intensity, compared to pure ZnO due to the incorporation of Ce. Increment of broad green emission intensity is observed with increased Ce doping in the precursor concentration for the Hot-Water treated films, which indicates the formation in Ce vacancies. Ce-doped ZnO films obtained which show promising optical properties can be used for the fabrication of optoelectronics devices utilizing substrates with low thermal stability such as organic polymers.
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optical properties of two dimensional zno nanosheets formed by Hot Water Treatment of zn foils
Solid State Communications, 2013Co-Authors: Wai Kian Tan, Khairunisak Abdul Razak, Zainovia Lockman, Go Kawamura, Hiroyuki Muto, Atsunori MatsudaAbstract:Abstract Two-dimensional ZnO nanosheets were formed on metallic Zn foils after Hot-Water Treatment at 90 °C for 4, 8, 12 and 24 h. The pHotoluminescence spectra of the as-formed ZnO nanosheets exhibit near band edge UV and green emissions; indicating their good crystallinity with presence of oxygen related defects. Raman scattering of the ZnO nanosheets indicated ZnO crystals of high quality were obtained, which was supported by high resolution transmission electron microscope (HR-TEM) results. This low-temperature formation of interconnected two-dimensional ZnO nanosheets with high quality would enable the utilization of substrates with low-thermal stability for optoelectronics applications.
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formation of highly crystallized zno nanostructures by Hot Water Treatment of etched zn foils
Materials Letters, 2013Co-Authors: Wai Kian Tan, Khairunisak Abdul Razak, Zainovia Lockman, Go Kawamura, Hiroyuki Muto, Atsunori MatsudaAbstract:Abstract The effects of surface oxidation of etched metallic Zn foils by Hot-Water Treatment at 90 °C for 4, 8, 12 and 24 h were investigated. ZnO nanostructures consisting of nanowires and nanorods were obtained at different Hot-Water Treatment times. The pHotoluminescence spectra of the as-formed ZnO nanostructures exhibit near band edge UV emission, indicating their good crystallinity. Further evidence of good crystallinity is the HR-TEM observations of the lattice fringes of wurtzite ZnO. Raman scattering of the ZnO nanostructures indicates that crystallinity is improved, and the number of oxygen vacancies is reduced at longer durations of Hot-Water Treatment.
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low temperature crystallization of tio2 nanotube arrays via Hot Water Treatment and their pHotocatalytic properties under visible light irradiation
Materials Chemistry and Physics, 2013Co-Authors: Go Kawamura, Hiroyuki Muto, Warapong Krengvirat, Srimala Sreekantan, Ahmad Fauzi Mohd Noor, Nobuaki Negishi, Atsunori MatsudaAbstract:Abstract This work demonstrates the facile method to crystallize TiO 2 nanotube arrays by simple immersion of amorphous TiO 2 nanotube arrays into Hot Water at ∼70–90 °C under ambient pressure and neutral pH. Hot Water Treatment induced the transformation of smooth nanotubes walls to granular anatase TiO 2 nanoparticles. Higher Treatment temperature and longer exposure time promoted the growth of anatase TiO 2 nanocrystallites, and also lowered number of oxygen vacancies ( V O •• ). Furthermore, it allowed the adsorption of hydroxyl (OH) species and H 2 O as well as the generation of the surface state, ca., Ti 3+ . The presence of interstitial carbon species and surface states enabled the visible-light absorption. The adsorbed OH species and H 2 O stimulated the pHotocatalytic oxidation by instantaneous reaction at the surface of nanotubes. Anatase TiO 2 nanocrystallites formed by Hot Water Treatment at 90 °C for 3 h exhibited efficient pHotocatalytic removal of dyes under visible-light irradiation with the decomposition rate of ∼11% h −1 , which is relatively higher than that of heat-treated arrays (∼9% h −1 ). The results indicate the potential of Hot Water Treatment for the formation of anatase TiO 2 nanocrystallites with efficient pHotocatalytic properties.
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antireflective properties of flowerlike alumina thin films on soda lime silica glass substrates prepared by the sol gel method with Hot Water Treatment
Thin Solid Films, 2007Co-Authors: Naoko Yamaguchi, Atsunori Matsuda, Tsutomu Minami, Kiyoharu Tadanaga, Masahiro TatsumisagoAbstract:Abstract The antireflective (AR) properties of Al 2 O 3 thin films with small roughness on soda–lime silica glass substrates were investigated. By immersing porous Al 2 O 3 thin films in Hot Water, nanocrystals of pseudoboehmite were formed on the film surface. The reflectance of the Al 2 O 3 films treated with Hot Water for 30 min was less than 0.5% in the wavelength region of 360–620 nm. The Al 2 O 3 films with small roughness resulting from the Hot Water Treatment become denser from their surface to the interface with the substrate, and the refractive index gradient brought by the structure results in excellent AR properties.
Masahiro Tatsumisago - One of the best experts on this subject based on the ideXlab platform.
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antireflective properties of flowerlike alumina thin films on soda lime silica glass substrates prepared by the sol gel method with Hot Water Treatment
Thin Solid Films, 2007Co-Authors: Naoko Yamaguchi, Atsunori Matsuda, Tsutomu Minami, Kiyoharu Tadanaga, Masahiro TatsumisagoAbstract:Abstract The antireflective (AR) properties of Al 2 O 3 thin films with small roughness on soda–lime silica glass substrates were investigated. By immersing porous Al 2 O 3 thin films in Hot Water, nanocrystals of pseudoboehmite were formed on the film surface. The reflectance of the Al 2 O 3 films treated with Hot Water for 30 min was less than 0.5% in the wavelength region of 360–620 nm. The Al 2 O 3 films with small roughness resulting from the Hot Water Treatment become denser from their surface to the interface with the substrate, and the refractive index gradient brought by the structure results in excellent AR properties.
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direct formation of zn al layered double hydroxide films with high transparency on glass substrate by the sol gel process with Hot Water Treatment
Crystal Growth & Design, 2006Co-Authors: Naoko Yamaguchi, Atsunori Matsuda, Kiyoharu Tadanaga, Tomohiko Nakamura, And Tsutomu Minami, Masahiro TatsumisagoAbstract:Amorphous Al2O3−ZnO thin films with various Zn/Al ratios were prepared on glass substrates by the sol−gel method with a heat Treatment at 400 °C for 30 min followed by immersion of the films in distilled Water at 100 °C to form nanocrystalline Zn−Al layered double hydroxide (LDH) with hexagonal structure. Zn−Al LDH nanocrystals were precipitated on the amorphous Al2O3−ZnO films with various Zn/Al ratios, and the maximum amount of nanocrystals was formed on the film of the Zn/Al atomic ratio of unity. Zn−Al LDH crystals with the size of 200−500 nm have been precipitated on glass substrates through Hot Water Treatment at temperatures lower than 100 °C.
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lowering of preparation temperatures of anatase nanocrystals dispersed coatings via sol gel process with Hot Water Treatment
Journal of the American Ceramic Society, 2005Co-Authors: Atsunori Matsuda, Tatsuo Matoda, Tsutomu Minami, Kiyoharu Tadanaga, Masahiro Tatsumisago, Toshihiro KogureAbstract:A longer period of time was necessary to form anatase nanocrystals on silica–titania gel coatings at lower Hot Water Treatment temperature, whereas considerable amounts of anatase nanocrystals were observed even at 38°C after a Treatment of 65 h. The coatings pre-heated at 60°C for 1 h and treated with Hot Water at 55°C for 15 h showed higher pHotocatalytic activity for methylene blue bleaching than the coatings prepared under the conditions with higher processing temperature close to 100°C. Such a high pHotocatalytic activity of the coatings obtained through low processing temperatures can be ascribed to a large specific surface area of the coatings and a smaller crystal size of the precipitated anatase.
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formation of anatase nanocrystals precipitated silica coatings on plastic substrates by the sol gel process with Hot Water Treatment
Journal of Sol-Gel Science and Technology, 2003Co-Authors: Atsunori Matsuda, Tatsuo Matoda, Tsutomu Minami, Kiyoharu Tadanaga, Toshihiro Kogure, Masahiro TatsumisagoAbstract:Anatase nanocrystals-precipitated silica coatings were formed on plastic substrates such as poly(ethylene terephtalate) (PET), acrylic resin (AC) and polycarbonate (PC) from silica-titania gel coatings with and without addition of poly(ethylene glycol) (PEG) by Hot Water Treatment. The maximum thickness of the coatings which can be formed without cracking or peeling-off was 100 to 200 nm for PET and PC substrates, whereas it was less than 50 nm for AC substrates. After a Hot Water Treatment at 90°C for 120 min, the size of the anatase nanocrystals increased to be 30 and 50 nm for the coatings obtained with and without PEG, respectively. Anatase nanocrystals were formed throughout the whole of the coatings obtained with PEG and were formed only on the surface of the coatings obtained without PEG. Both coatings obtained with and without PEG were highly transparent. The plastic substrates with coatings obtained without PEG showed good weathering resistance owing to the protective effects of the residual silica under-layer. The coatings obtained with PEG showed higher pHotocatalytic activities than those obtained without PEG due to smaller size and higher dispersion of anatase nanocrystals in the coatings.
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evaluation of pHotocatalytic activity of transparent anatase nanocrystals dispersed silica films prepared by the sol gel process with Hot Water Treatment
Journal of Sol-Gel Science and Technology, 2003Co-Authors: Atsunori Matsuda, Tatsuo Matoda, Masahiro Tatsumisago, Toshihiro Kogure, Yoshinori Kotani, Tsutomu MinamiAbstract:Anatase nanocrystals were precipitated mainly at the surface of the silica-titania gel films with Hot Water Treatment, whereas the addition of poly(ethylene glycol) (PEG) in the films led to the dispersion of anatase nanocrystals in the whole of the films after the Treatment. Both films with and without PEG showed high pHotocatalytic activities for acetaldehyde, NO x and stearic acid in the gas-solid system, and for methylene blue and potassium iodide in the liquid-solid system. The addition of PEG improved the pHotocatalytic activities of the resultant films due to the smaller anatase crystallites and the porous film structure. The residual silica under-layer of the superficially anatase-precipitated films is expected to act as a protective one for an organic polymer substrate against the pHotocatalytic degradation.
Tsutomu Minami - One of the best experts on this subject based on the ideXlab platform.
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antireflective properties of flowerlike alumina thin films on soda lime silica glass substrates prepared by the sol gel method with Hot Water Treatment
Thin Solid Films, 2007Co-Authors: Naoko Yamaguchi, Atsunori Matsuda, Tsutomu Minami, Kiyoharu Tadanaga, Masahiro TatsumisagoAbstract:Abstract The antireflective (AR) properties of Al 2 O 3 thin films with small roughness on soda–lime silica glass substrates were investigated. By immersing porous Al 2 O 3 thin films in Hot Water, nanocrystals of pseudoboehmite were formed on the film surface. The reflectance of the Al 2 O 3 films treated with Hot Water for 30 min was less than 0.5% in the wavelength region of 360–620 nm. The Al 2 O 3 films with small roughness resulting from the Hot Water Treatment become denser from their surface to the interface with the substrate, and the refractive index gradient brought by the structure results in excellent AR properties.
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lowering of preparation temperatures of anatase nanocrystals dispersed coatings via sol gel process with Hot Water Treatment
Journal of the American Ceramic Society, 2005Co-Authors: Atsunori Matsuda, Tatsuo Matoda, Tsutomu Minami, Kiyoharu Tadanaga, Masahiro Tatsumisago, Toshihiro KogureAbstract:A longer period of time was necessary to form anatase nanocrystals on silica–titania gel coatings at lower Hot Water Treatment temperature, whereas considerable amounts of anatase nanocrystals were observed even at 38°C after a Treatment of 65 h. The coatings pre-heated at 60°C for 1 h and treated with Hot Water at 55°C for 15 h showed higher pHotocatalytic activity for methylene blue bleaching than the coatings prepared under the conditions with higher processing temperature close to 100°C. Such a high pHotocatalytic activity of the coatings obtained through low processing temperatures can be ascribed to a large specific surface area of the coatings and a smaller crystal size of the precipitated anatase.
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formation of anatase nanocrystals precipitated silica coatings on plastic substrates by the sol gel process with Hot Water Treatment
Journal of Sol-Gel Science and Technology, 2003Co-Authors: Atsunori Matsuda, Tatsuo Matoda, Tsutomu Minami, Kiyoharu Tadanaga, Toshihiro Kogure, Masahiro TatsumisagoAbstract:Anatase nanocrystals-precipitated silica coatings were formed on plastic substrates such as poly(ethylene terephtalate) (PET), acrylic resin (AC) and polycarbonate (PC) from silica-titania gel coatings with and without addition of poly(ethylene glycol) (PEG) by Hot Water Treatment. The maximum thickness of the coatings which can be formed without cracking or peeling-off was 100 to 200 nm for PET and PC substrates, whereas it was less than 50 nm for AC substrates. After a Hot Water Treatment at 90°C for 120 min, the size of the anatase nanocrystals increased to be 30 and 50 nm for the coatings obtained with and without PEG, respectively. Anatase nanocrystals were formed throughout the whole of the coatings obtained with PEG and were formed only on the surface of the coatings obtained without PEG. Both coatings obtained with and without PEG were highly transparent. The plastic substrates with coatings obtained without PEG showed good weathering resistance owing to the protective effects of the residual silica under-layer. The coatings obtained with PEG showed higher pHotocatalytic activities than those obtained without PEG due to smaller size and higher dispersion of anatase nanocrystals in the coatings.
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evaluation of pHotocatalytic activity of transparent anatase nanocrystals dispersed silica films prepared by the sol gel process with Hot Water Treatment
Journal of Sol-Gel Science and Technology, 2003Co-Authors: Atsunori Matsuda, Tatsuo Matoda, Masahiro Tatsumisago, Toshihiro Kogure, Yoshinori Kotani, Tsutomu MinamiAbstract:Anatase nanocrystals were precipitated mainly at the surface of the silica-titania gel films with Hot Water Treatment, whereas the addition of poly(ethylene glycol) (PEG) in the films led to the dispersion of anatase nanocrystals in the whole of the films after the Treatment. Both films with and without PEG showed high pHotocatalytic activities for acetaldehyde, NO x and stearic acid in the gas-solid system, and for methylene blue and potassium iodide in the liquid-solid system. The addition of PEG improved the pHotocatalytic activities of the resultant films due to the smaller anatase crystallites and the porous film structure. The residual silica under-layer of the superficially anatase-precipitated films is expected to act as a protective one for an organic polymer substrate against the pHotocatalytic degradation.
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pHotocatalytic decomposition of acetaldehyde with anatase nanocrystals dispersed silica films prepared by the sol gel process with Hot Water Treatment
Journal of Sol-Gel Science and Technology, 2001Co-Authors: Atsunori Matsuda, Masahiro Tatsumisago, Toshihiro Kogure, Yoshinori Kotani, Tsutomu MinamiAbstract:Anatase nanocrystals of 5 to 10 nm in diameter were formed in the silica-titania films by Treatment with Hot Water. The formation of nanocrystals with Hot Water Treatment was a unique phenomenon to the silica-titania system and the addition of organic polymers such as PEG was indispensable for the high dispersion of anatase nanocrystals in the films. The hydrolysis of Si—O—Ti bonds with Hot Water was considered to play an important role for the formation of anatase nanocrystals. The resultant films were transparent even after the formation of anatase nanocrystals. Acetaldehyde was pHotocatalytically decomposed into CO2 on the films which were subjected to a Hot Water Treatment. The amounts of generated CO2 were twice of that of introduced acetaldehyde, indicating that the total acetaldehyde was completely decomposed to CO2. Anatase nanocrystals-dispersed films can be formed on various kinds of substrates including those with poor heat resistance such as organic polymers and organisms by this process, so that the substrates coated with the films are expected to be widely used for pHotocatalytic applications.
Somsiri Sangchote - One of the best experts on this subject based on the ideXlab platform.
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effects of cinnamon extract chitosan coating Hot Water Treatment and their combinations on crown rot disease and quality of banana fruit
Postharvest Biology and Technology, 2007Co-Authors: Pongphen Jitareerat, Sirichai Kanlayanarat, Somsiri SangchoteAbstract:Abstract The antifungal activities of cinnamon extract (CE), piper extract (PE) and garlic extract (GE) were evaluated on banana crown rot fungi ( Colletotrichum musae , Fusarium spp. and Lasiodiplodia theobromae ) in vitro . The assay was conducted with extracts of CE, PE and GE with concentrations of 0, 0.1, 0.5, 1.0, 5.0, 10.0 and 0.75 g L −1 of carbendazim (CBZ) on potato dextrose agar at room temperature. CE completely inhibited conidial germination and mycelial growth of all fungi at 5.0 g L −1 . PE totally suppressed mycelial growth of all fungi at 5.0 g L −1 and conidial germination at 10.0 g L −1 except for Fusarium spp. GE had no significant effects but low concentrations (0.1 and 0.5 g L −1 ) enhanced germ tube elongation of the three fungi. The ED 50 values were higher for mycelial growth than for conidia except for Fusarium spp. Combined Treatments were investigated on crown rot development in banana fruit ( Musa AAA group ‘Kluai Hom thong’). Treatments included 5.0 g L −1 CE, 1% (w/v) chitosan solution, Hot Water Treatment (HWT, 45 °C for 20 min), CE plus chitosan, CE plus HWT and 0.75 g L −1 of CBZ, applied before and after inoculation of the fruit. Crown rot development was assessed during storage at 13 °C for 7 weeks. Disease development was least (25%) on CE treated fruit after inoculation compared to CBZ but was higher when CE was applied before inoculation. Chitosan significantly delayed ripening as in terms of peel color, firmness, soluble solids and disease severity. CE showed no negative effects on quality of fruit. CE plus HWT caused unacceptable peel browning.
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effects of cinnamon extract chitosan coating Hot Water Treatment and their combinations on crown rot disease and quality of banana fruit
Postharvest Biology and Technology, 2007Co-Authors: Pongphen Jitareerat, Sirichai Kanlayanarat, Somsiri SangchoteAbstract:Abstract The antifungal activities of cinnamon extract (CE), piper extract (PE) and garlic extract (GE) were evaluated on banana crown rot fungi ( Colletotrichum musae , Fusarium spp. and Lasiodiplodia theobromae ) in vitro . The assay was conducted with extracts of CE, PE and GE with concentrations of 0, 0.1, 0.5, 1.0, 5.0, 10.0 and 0.75 g L −1 of carbendazim (CBZ) on potato dextrose agar at room temperature. CE completely inhibited conidial germination and mycelial growth of all fungi at 5.0 g L −1 . PE totally suppressed mycelial growth of all fungi at 5.0 g L −1 and conidial germination at 10.0 g L −1 except for Fusarium spp. GE had no significant effects but low concentrations (0.1 and 0.5 g L −1 ) enhanced germ tube elongation of the three fungi. The ED 50 values were higher for mycelial growth than for conidia except for Fusarium spp. Combined Treatments were investigated on crown rot development in banana fruit ( Musa AAA group ‘Kluai Hom thong’). Treatments included 5.0 g L −1 CE, 1% (w/v) chitosan solution, Hot Water Treatment (HWT, 45 °C for 20 min), CE plus chitosan, CE plus HWT and 0.75 g L −1 of CBZ, applied before and after inoculation of the fruit. Crown rot development was assessed during storage at 13 °C for 7 weeks. Disease development was least (25%) on CE treated fruit after inoculation compared to CBZ but was higher when CE was applied before inoculation. Chitosan significantly delayed ripening as in terms of peel color, firmness, soluble solids and disease severity. CE showed no negative effects on quality of fruit. CE plus HWT caused unacceptable peel browning.
Toshihiro Kogure - One of the best experts on this subject based on the ideXlab platform.
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lowering of preparation temperatures of anatase nanocrystals dispersed coatings via sol gel process with Hot Water Treatment
Journal of the American Ceramic Society, 2005Co-Authors: Atsunori Matsuda, Tatsuo Matoda, Tsutomu Minami, Kiyoharu Tadanaga, Masahiro Tatsumisago, Toshihiro KogureAbstract:A longer period of time was necessary to form anatase nanocrystals on silica–titania gel coatings at lower Hot Water Treatment temperature, whereas considerable amounts of anatase nanocrystals were observed even at 38°C after a Treatment of 65 h. The coatings pre-heated at 60°C for 1 h and treated with Hot Water at 55°C for 15 h showed higher pHotocatalytic activity for methylene blue bleaching than the coatings prepared under the conditions with higher processing temperature close to 100°C. Such a high pHotocatalytic activity of the coatings obtained through low processing temperatures can be ascribed to a large specific surface area of the coatings and a smaller crystal size of the precipitated anatase.
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formation of anatase nanocrystals precipitated silica coatings on plastic substrates by the sol gel process with Hot Water Treatment
Journal of Sol-Gel Science and Technology, 2003Co-Authors: Atsunori Matsuda, Tatsuo Matoda, Tsutomu Minami, Kiyoharu Tadanaga, Toshihiro Kogure, Masahiro TatsumisagoAbstract:Anatase nanocrystals-precipitated silica coatings were formed on plastic substrates such as poly(ethylene terephtalate) (PET), acrylic resin (AC) and polycarbonate (PC) from silica-titania gel coatings with and without addition of poly(ethylene glycol) (PEG) by Hot Water Treatment. The maximum thickness of the coatings which can be formed without cracking or peeling-off was 100 to 200 nm for PET and PC substrates, whereas it was less than 50 nm for AC substrates. After a Hot Water Treatment at 90°C for 120 min, the size of the anatase nanocrystals increased to be 30 and 50 nm for the coatings obtained with and without PEG, respectively. Anatase nanocrystals were formed throughout the whole of the coatings obtained with PEG and were formed only on the surface of the coatings obtained without PEG. Both coatings obtained with and without PEG were highly transparent. The plastic substrates with coatings obtained without PEG showed good weathering resistance owing to the protective effects of the residual silica under-layer. The coatings obtained with PEG showed higher pHotocatalytic activities than those obtained without PEG due to smaller size and higher dispersion of anatase nanocrystals in the coatings.
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evaluation of pHotocatalytic activity of transparent anatase nanocrystals dispersed silica films prepared by the sol gel process with Hot Water Treatment
Journal of Sol-Gel Science and Technology, 2003Co-Authors: Atsunori Matsuda, Tatsuo Matoda, Masahiro Tatsumisago, Toshihiro Kogure, Yoshinori Kotani, Tsutomu MinamiAbstract:Anatase nanocrystals were precipitated mainly at the surface of the silica-titania gel films with Hot Water Treatment, whereas the addition of poly(ethylene glycol) (PEG) in the films led to the dispersion of anatase nanocrystals in the whole of the films after the Treatment. Both films with and without PEG showed high pHotocatalytic activities for acetaldehyde, NO x and stearic acid in the gas-solid system, and for methylene blue and potassium iodide in the liquid-solid system. The addition of PEG improved the pHotocatalytic activities of the resultant films due to the smaller anatase crystallites and the porous film structure. The residual silica under-layer of the superficially anatase-precipitated films is expected to act as a protective one for an organic polymer substrate against the pHotocatalytic degradation.
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pHotocatalytic decomposition of acetaldehyde with anatase nanocrystals dispersed silica films prepared by the sol gel process with Hot Water Treatment
Journal of Sol-Gel Science and Technology, 2001Co-Authors: Atsunori Matsuda, Masahiro Tatsumisago, Toshihiro Kogure, Yoshinori Kotani, Tsutomu MinamiAbstract:Anatase nanocrystals of 5 to 10 nm in diameter were formed in the silica-titania films by Treatment with Hot Water. The formation of nanocrystals with Hot Water Treatment was a unique phenomenon to the silica-titania system and the addition of organic polymers such as PEG was indispensable for the high dispersion of anatase nanocrystals in the films. The hydrolysis of Si—O—Ti bonds with Hot Water was considered to play an important role for the formation of anatase nanocrystals. The resultant films were transparent even after the formation of anatase nanocrystals. Acetaldehyde was pHotocatalytically decomposed into CO2 on the films which were subjected to a Hot Water Treatment. The amounts of generated CO2 were twice of that of introduced acetaldehyde, indicating that the total acetaldehyde was completely decomposed to CO2. Anatase nanocrystals-dispersed films can be formed on various kinds of substrates including those with poor heat resistance such as organic polymers and organisms by this process, so that the substrates coated with the films are expected to be widely used for pHotocatalytic applications.
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effects of addition of poly ethylene glycol on the formation of anatase nanocrystals in sio2 tio2 gel films with Hot Water Treatment
Chemistry of Materials, 2001Co-Authors: Yoshinori Kotani, Atsunori Matsuda, Masahiro Tatsumisago, Toshihiro Kogure, Tsutomu MinamiAbstract:Effects of the addition of poly(ethylene glycol) (PEG) in SiO2−TiO2 gel films on the formation of anatase nanocrystals with Hot Water Treatment were investigated. Anatase nanocrystals were formed in the whole SiO2−TiO2 gel films with the addition of PEG by the Treatment, whereas in the films without PEG the nanocrystals were formed mainly on the surface of the films. PEG in the SiO2−TiO2 films was completely leached out with the Hot Water Treatment in about 1 min. The pores produced by the leaching of PEG probably allow anatase nanocrystals to be formed inside the films. Hydrolysis of Si−O−Ti bonds was presumed to play an important role in the nucleation of anatase nanocrystals in the Hot Water Treatment.