• Rapid Communication in Photoscience
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• v.4 no.1
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• pp.19-21
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• 2015

Zeolite is an ideal host material for encapsulating nano-size metal catalyst species because of its defined microporous structure, prominent adsorption/condensation properties, high surface area, chemical/thermal stability, and transparency to light. In this study, $TiO_2$ photocatalyst was incorporated in highly hydrophobic Y zeolite and its photocatalytic activity was examined in the photocatalytic oxidation of olefins under UV-light irradiation using molecular oxygen as an oxygen source. $TiO_2$ nanoparticles incorporated in hydrophobic Y zeolite exhibited a markedly enhanced photocatalytic activity compared with bare $TiO_2$ owing to its excellent affinity toward organic moieties, which facilitates the mass transfer of organic substrates and allows them to efficiently access to the neighboring active $TiO_2$ surface.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.153-154
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• 2018

As the air pollution progresses, the pollution degree of the indoor air quality is increased, and when the pollution degree of the indoor air quality is increased, it causes respiratory diseases and skin diseases. In addition, volatile organic compounds are released from the materials used for architectural interior decoration, and volatile organic compounds are the main cause of polluting indoor air quality. In order to improve indoor air quality, we tried to secure indoor air quality pollution by using photocatalyst which has the function of decomposing harmful substances. photocatalyst is a material that promotes chemical reaction by absorbing light. The photocatalyst used in the experiment was TiO₂, In this study, an adsorption type hardener for reducing volatile organic compounds was prepared by photocatalytic reaction. the formaldehyde and CO₂ concentrations of the cured products were analyzed according to the TiO₂ content.

• Korean Journal of Materials Research
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• v.12 no.6
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• pp.482-487
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• 2002

A $TiO_2$ film for photocatalyst was prepared by anodic oxidation at 180V in acidic electrolyte and film formation mechanism was studied. The major part of anodic $TiO_2$ film consisted of anatase type structure and surface morphology exhibited a porous cell structure. The thickness growth rate of the oxide film with anodization time revealed two-stage slope corresponds to the surface morphology between anodic films. The growth of pores on cell structure and the growth rate of film with two-stage slope are related to the constant formation rate of the $TiO_2$ layer.

• Journal of Powder Materials
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• v.9 no.2
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• pp.110-115
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• 2002

In order to obtain the nano size $10wt%Cu-TiO_2$composite powders by mechanical alloying method for useful composite catalysis, the effects of mechanical alloying time on the formationof $10wt%Cu-TiO_2$ composite powders were analyzed. The phase transformation behaviors were experimented as the heat treating temperature increased. Homogeneous 10wt% Cu-rutile type $TiO_2$composite powders were synthesized in 40 hours by mechanical alloying. After 60 hours mechanical alloying 50 nm size $TiO_2$powders were obtained. Both the phase of mechanically alloyed 10 wt% $Cu-TiO_2$ and pure $TiO_2$ powders were not transformed to anatase after annealing at the temperature range between 350 to 500 $^{\circ}C$. The intermetallic compound of $Cu_2Ti_4$O was formed after 10 hours mechanical alloying, however it could be considered that this intemetallic phase dose not prevent the transformation of rutile $TiO_2$ to the anatase phase after heat treatment at the temperature between 350 and $550^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.477-480
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• 2002

A new microporous TiO2-pillared layered titanate has been successfully prepared by hybridizing the exfoliated titanate with the anatase TiO2 nano-sol. According to the X-ray diffraction analysis and N2 adsorption-desorption isotherms, the TiO2-pillared layered titanate showed a pillar height of ~2 nm with a high surface area of ~460 m2/g and a pore size of ~0.95 nm, indicating that a microporous pillar structure is formed. Its photocatalytic activity was evaluated by measuring the photodegradation rate of 4-chlorophenol during irradiation of catalyst suspensions in an aqueous solution. An enhancement in activity of ca. 170% was obtained for TiO2-pillared layered titanate compared to that of the pristine compound such as layered cesium titanate.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.95.2-95.2
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• 2017

Anodic TiO2 nanostructures have wide applications due to their various functional properties such as wide band-gap, chemical stability, and anti-corrosiveness. In order to enhance the properties, several approaches to fabricate TiO2 structures have been developed. Especially, TiO2 nanotube arrays prepared by anodization in a fluoride electrolyte show impressive properties for dye sensitized solar cells1 and photocatalyst. In this presentation, we introduce new types of TiO2 nanostructures beyond TiO2 nanotubes that are fabricated by anodization at high temperature in a glycerol/phosphate electrolyte. We show that depending on the anodization parameters different self-organized morphologies - of highly aligned, high aspect ratio oxide structures can be formed. Critical factor for growth and the use for dye sensitized solar cells and photocatalyst will be discussed.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.4
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• pp.363-370
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• 2001

In this study, TiO$_2$, the popular photocatalyst, was used to decompose ethanol. TiO$_2$was prepared by the sol -gel method and coated on pyrex stick. A 15W, UV-A lamp was used as the UV light source and il gas chromatography (HP 5890) was used to confirm the concentrations of ethanol, $CO_2$and the intermediates. Variation of preparation parameters and calcination temperature for TiO$_2$photocatalysts in the sol -gel method caused changes of ethanol decomposition activity. The best ethanol photodecomposition activity was obtained on the sample when prepared with 0.14 mol of HCI, a mol of ethanol and 1.3 mol of TTIP ware mixed in sol-gel process and calcinated at 50$0^{\circ}C$ for 3 hours. Acetaldehyde was detected as an intermediate and decomposed to carbon dioxide and water at the end of the reaction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1579-1584
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• 2015

In photocatalytic reaction, the doping of metal matter can alter the titania surface properties. As such the metal matter can increase the rate of the reaction. The influence of metal doping and calcination condition of $TiO_2$ photocatalyst was investigated at the batch-type photoreactor. Several metal matters were doped to the $TiO_2$ catalyst to improve photodegradation efficiency. During the experiments, water content was 3wt%, and reactor temperature was $40^{\circ}C$. Palladium-doped $TiO_2$ was found to be the best, where as platinum or tungsten-added also showed good results. Additional doping of platinum or tungsten on Pd/$TiO_2$ had no increase on the removal efficiency. To obtain proper calcination condition, various experiments about calcination temperature and time were carried out. As a result, the optimum calcination condition was temperature of $400^{\circ}C$, time of 1 hour.

• Journal of the Korean Ceramic Society
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• v.41 no.6
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• pp.471-475
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• 2004

TiO$_2$, SiO$_2$, and PBA(Pseudo Boehemite Alumina) sol were prepared by sol-gel process. The particle sizes of these sol exhibited uniform 10∼30 nm. As the amount of SiO$_2$ sol increased, the temperature of phase transition (from anatase phase to rutile phase) was raised temperature than $600^{\circ}C$, which attributed to the enhanced photocatalyst properties. Also, the anatase phase was obtained with very small amount of the rutile phase from the addition of SiO$_2$ (10∼30 wt%) at annealing temperature of 120$0^{\circ}C$. The specimen with 20 wt% SiO$_2$ sol exhibited the maximum photocatalyst properties. But, the specimen with PBA sol did not affect photocatalytic activity due to the presence of rutile phase.

• Journal of environmental and Sanitary engineering
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• v.17 no.2
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• pp.26-33
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• 2002

Ultimate objective of industrial hygiene is the prevention of health impairment that may result from exposure to chemicals at workplace. Workers in solvent thinner-using occupation environment may be highly exposed to VOCs (volatile organic compounds) because solvent thinner has been used extensively such as painting, spraying, degreasing, coating and so on in Korea. The purpose of this study was to recognize, evaluate, and propose the control methods of VOCs from solvent thinner-using workplace. Five target volatile organic compounds (benzene, toluene, ethylbenzene, o-xylene, and m-xylene) were monitored in H company of Shiwa Industrial Complex and analyzed in perosnal, occupational indoor and outdoor during working hours simultaneously. Engineering control such as local ventilation should be made in considering the long-term exposure, though measured VOCs concentration did not exceed the workplace exposure standards. In addition, air cleaning device should be installed in local ventilation because Shiwa Industrial Complex has had the serious ambient air pollution. Currently, environmental purification using $TiO_2$ photocatalyst have attracted a great deal of attention with increasing number of recent environmental problems. In this study, $TiO_2$ sol coated on the ceramic bead was prepared by sol-gel method and the photodegradation of target compounds was investigated in gas phase by the exposure to UV-A lamp(365nm) in a batch system.