• Journal of the Korean GEO-environmental Society
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• v.7 no.4
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• pp.5-13
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• 2006

This study was conducted to evaluate the application of $UV/TiO_2/H_2O_2$ process for treating humic acid and heavy metals in surface water. Removal efficiency of $UV/TiO_2/H_2O_2$ process was much more efficient than that of $UV/TiO_2$ process for humic acid and heavy metals removal. The removal rate of humic acid and heavy metals increased with the increase of $TiO_2$ dosage and UV intensity, however decreased with more than 0.3 g/L of $TiO_2$ dosage. The addition of $H_2O_2$ as an oxidant was a positive effect for the removal rate of humic acid and heavy metals especially in the concentration of 50 mg/L $H_2O_2$.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.203.2-203
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• 2003

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.60.2-60.2
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• 2010

A $TiO_2$ films in dye-sensitized solar cells was fabricated using $TiO_2$ colloidal sol prepared from titanium iso-propoxide used as a starting material by applying the sol-gel method. It was characterized by particle size analyzer, XRD, FE-SEM, and BET analysis. The adsorption isotherms of dye molecule on $TiO_2$ films were obtained at three different temperatures (30, 45, $60^{\circ}C$) and at three different pH (3, 5, 7). The adsorption kinetics of dye molecule on $TiO_2$ films were obtained at three different temperatures (30, 45, $60^{\circ}C$. The adsorption experimental data were correlated with Langmuir isotherm model and pseudo-second-order model. Also the isosteric enthalpies of dye adsorption were calculated by the Clausius-Clapeyron equation. In addition, the adsorption energy distribution functions which describe heterogeneous characteristics of nanocrystalline $TiO_2$ film surface were calculated by using the generalized nonlinear regularization method. We found that efficient adsorption of N719 dye from aqueous solution onto $TiO_2$ films can be successfully achieved by dye adsorption conditions and morphology of $TiO_2$ films.

• Korean Journal of Materials Research
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• v.13 no.7
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• pp.436-441
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• 2003

The characteristics of <112> orientation were studied for the $TiO_2$thin films, which were prepared on the glass by CVD (chemical vapor deposition) at various substrate temperatures. It was confirmed that $TiO_2$ films exhibited <112>-preferred orientation in a specific temperature range. Although $TiO_2$polycrystalline film grown deposited at relatively low temperature showed the growth of random directions, the <112>-preferred orientation was gradually developed with increasing deposition temperature. According to exhibit higher degree of <112>-preferred orientation, $TiO_2$thin film showed porous surface morphology, well-developed columnar structure, and deeper voids resulted from non-aggregation of columns were observed. In addition, transmittance was enhanced. Therefore, the growth of $TiO_2$with <112>-preferred orientation is suitable for glass coating because of predominance of photocatalytic efficiency and transmittance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.7
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• pp.537-542
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• 2012

DSSCs efficiency by thickness of $TiO_2$ photoelectrode and thickness differences between two substrates studied. DSSCs is made of the doctor blade method and photoelectrode annealing temperature elevated in a different ways. In addition, cells efficiencies of according to the different thickness between $TiO_2$ photoelectrode substrate and Pt counter electrode was measured. Efficiency of DSSCs made with $TiO_2$ photoelectrode of 18 ${\mu}m$ thickness and the gap difference between the substrate 28 ${\mu}m$ shows a highest 4.805% efficiency.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.214-215
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• 2018

This paper has been researched that the earlier compressive strength of the cement pastes containing nano-TiO₂ particle curing 1day, 3days and 7days. For the compressive strength measurements, all samples(dimensions 50×50×50mm) were prepared in accordance with ASTM C109. The compressive strength of the specimens with nano-TiO₂ at the early age(1day, 3days and 7days) stage was lower than that of the reference group. Therefore, nano-TiO₂ has little positive effect on the improvement of the compressive strength of cement pastes during early ages.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1491-1493
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• 2002

The 0.5$Ba_2Ti_9O_{20}$-0.5Mg$TiO_3$ ceramics were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature by XRD. According to the X-ray diffraction patterns, major phases of the 0.5$Ba_2Ti_9O_{20}$-0.5Mg$TiO_3$ ceramics were coexisted. Also the secondary phase of Mg$Ti_2O_5$, Ba$Mg_6Ti_6O_{19}$ and the unreacted $TiO_2$ phase were existed. In the case of 0.5$Ba_2Ti_9O_{20}$-0.5Mg$TiO_3$ ceramics sintered $1350^{\circ}C$, dielectric constant, quality factor and temperature coefficient of resonant frequency were 33.7, 54,900GHz, -12.5ppm/$^{\circ}C$, respectively.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1105-1114
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• 1996

The characteristic and performance of ${\beta}-PbO_2$ layer electrodeposited on ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ substrate by adding sodium lauryl sulfate and $TiO_2$ powder in lead nitrate solution were investigated by using XRD, SEM, cyclic voltammograms, and macro-elctrolysis. Results of XRD analysis ascertain that ${\beta}-PbO_2$ layers electrodeposited in the presence of sodium lauryl sulfate and $TiO_2$, powder on ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ substrate have the same tetragonal structure as pure ${\beta}-PbO_2$ layers. The SEM results show that sodium lauryl sulfate tend to diminish crystal size of the deposited layer. The ${\beta}-PbO_2$ electrode electrodeposited in the presence of sodium lauryl sulfate and $TiO_2$ powder gives significantly improved oxygen overvoltage and durability for anodic oxidation in KOH and $HClO_4$ supporting electrolyte. Electrode performance and durability for the evolution of ozone in perchloric acid solution have been investigated by using ${\beta}-PbO_2$ electrodes electrodeposited on Titanium $madras^{(R)}$. It was ascertained that the $PbO_2$ electrode electrodeposited on ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ $madras^{(R)}$ by adding sodium lauryl sulfate and $TiO_2$ powder in $HClO_4$ supporting electrolyte had the highest current efficiency and durability.

• Applied Microscopy
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• v.46 no.1
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• pp.37-44
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• 2016

In this study $TiO_2$/reduced graphene oxide ($TiO_2/rGO$) bipyramid with tunable nanostructure was fabricated by two-step solvothermal process and subsequent heat-treatment in air. The as-synthesized anatase $TiO_2$ nanocrystals possessed morphological bipyramid with exposed dominantly by (101) facets. Polyethylenimine was utilized during the combination of $TiO_2$ and graphene oxide (GO) to tune the surface charge, hindering the restack of graphene during solvothermal process and resulting in 1 to 5 layers of rGO wrapped on $TiO_2$ surface. After a further calcination, a portion of carbon quantum dots (CQDs) with a diameter about 2 nm were produced owing to the oxidizing and cutting of rGO on $TiO_2$. The as-prepared $TiO_2/rGO$ hybrid showed a highly photocatalytic activity, which is about 3.2 and 7.7 times enhancement for photodegradation of methyl orange with compared to pure $TiO_2$ and P25, respectively. We assume that the improvement of photocatalysis is attributed to the chemical bonding between rGO/CQDs and $TiO_2$ that accelerates photogenerated electron-hole pair separation, as well as enhances light harvest.

• Electrical & Electronic Materials
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• v.8 no.2
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• pp.224-228
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• 1995

0.15(B $a_{0.95}$ S $r_{0.05}$)O-0.15S $m_{2}$ $O_{3}$-0.7Ti $O_{2}$ ceramics were fabricated by the mixed-oxide method. Microwave dielectric properties were investigated with sintering conditions. Increasing the sintering temperature from 1300 to 1375[.deg. C], the sintered density was increased from 5.44 to 5.63[g/c $m^{3$]. Increasing the sintering temperature, dielectric constant and quality factor were increased and temperature coefficient of resonant frequency was independent of sintering temperature. In the specimen sintered at 1375[.deg. C], dielectric constant, quality factor and temperature coefficient of resonant frequency were 80.79, 2784(at 3[GHz]), +11.07[ppm/.deg. C], respectively..