• 공업화학
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• 제31권6호
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• pp.674-678
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• 2020

본 연구에서는 상온 조건에서 추가적인 에너지원 없이 H2 산화가 가능한 Pd/TiO2 촉매를 제조하였고, 지지체인 TiO2의 비표면적은 Pd/TiO2 촉매의 H2 산화 반응 성능과 비례하지는 않은 것을 확인하였다. 또한 촉매의 물성 변화에 의한 성능 영향 평가를 위하여 La2O3를 Pd/TiO2 촉매에 첨가하였다. La2O3를 TiO2에 함량별로 첨가하여 Pd/La2O3-TiO2를 제조하였고, CO chemisorption 분석을 진행하였다. Pd/TiO2(G) 촉매의 전환율(14% at 0.5% H2)과 비교하여 Pd/La2O3-TiO2 촉매가 74% 전환율로 5배 이상의 성능 증진이 나타났다. Pd/La2O3-TiO2 촉매는 활성금속인 Pd의 metal dispersion이 클수록 H2 산화반응에 유리한 것으로 분석되었다. 하지만 첨가되는 La2O3가 10%를 초과하게 되면 촉매 성능이 다시 감소하는 것을 알 수 있었다. 마지막으로 Pd/La2O3-TiO2 촉매의 물성이 지배적인 영향을 미치는 것은 주입되는 H2가 0.3~0.5% 농도 조건까지이며, 1% 이상의 H2 농도부터는 물질전달이 촉매 반응속도를 지배하는 것으로 판단된다.

• 한국염색가공학회지
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• 제25권2호
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• pp.118-125
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• 2013

Poly(vinyl alcohol) (PVA)/titanium dioxide ($TiO_2$) composite nanofibers were produced at different $TiO_2$ concentrations (0.5, 1 and 1.5 wt.%) using the electrospinning method. The parameters of electrospinning including polymer contents, voltage and tip-to-collector distance (TCD) were optimized for fabrication process. The study showed that 7.5 wt.% PVA, 15 kV applied voltage and 15 cm TCD are the best condition to obtain uniform PVA/$TiO_2$ nanofibers. $TiO_2$ nanoparticles give significant effect in fiber morphology. $TiO_2$ content increases the diameter of the fibers and roughen the fiber surfaces. The PVA/$TiO_2$ nanofibers were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.269-269
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• 2010

고주파 마그네트론 동시 스퍼터링법을 이용하여 $TiO_2$ 박막에 탄소를 도핑한 C/$TiO_2$ 박막을 제작하고, 박막의 두께와 탄소 도핑량에 따른 물리적, 광학적 특성을 조사하였다. 스테인레스강을 기판으로 사용하였으며, $TiO_2$ 박막과 기판의 열팽창계수 차이에 의한 크랙을 방지하기 위하여 Ti 박막을 DC 마그네트론 스퍼터링 장치를 이용하여 기판위에 증착시킨 후 실험을 진행하였다. EMP(Essential Macleod Program) 시뮬레이션을 이용하여 막의 층상구조, 두께, 물질변화를 통한 다양한 색상의 칼라를 구현하고 투과율, 반사율 등을 포함한 다양한 광학 특성을 사전 예측하였다. 제작된 박막은 투께 및 밀도에 따라 다양한 색상을 구현하였으며, 박막내의 흡수와 산란효과에 의해 굴절률이 감소하였다. 또한 순수 $TiO_2$ 박막보다 접합력 및 경도가 증가함을 알 수 있었다.

• 한국광학회:학술대회논문집
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• 한국광학회 2008년도 동계학술발표회 논문집
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• pp.175-176
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• 2008

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 하계학술발표회
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• pp.282-283
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• 2003

TiO$_2$ 박막은 높은 굴절률과 유전 상수를 가지며, 가시광선과 근적외선 영역에서 우수한 투과성을 나타낸다. 따라서, 전기적, 광학적 특성이 우수한 광학코팅에 응용되고 있다. 또한 화학적으로 안정하고 비교적 큰 에너지 밴드 갭을 지닌 반도체 물질로서 유전체 다층 박막을 제작하는데 있어서 중요한 물질로 사용되고 있다. TiO$_2$ 박막을 제작하기 위한 물리적인 방법으로는 sputtering, anodic 또는 thermal, e-beam evaporation 등이 이용되고 있으며, sol-gel법, CVD 등과 같은 화학적인 방법도 이용되고 있다. (중략)

• 한국세라믹학회지
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• 제36권10호
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• pp.1075-1079
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• 1999

LaSrCoO3 thin films were spin-coated onto the SrTiO3(100) substrates by the chemical solution process. X-ray diffraction $\theta$-2$\theta$ scans and X-ray diffraction $\beta$ scans were used to determine the crystallinity and in -plane alignment behavior of the films. The X-ray diffraction pattern showed the film obtained by annealing at 80$0^{\circ}C$ was highly oriented. The X-ray diffraction pole-figure analysis and reciprocal-space mapping (2$\theta$-$\Delta$$\omega$ scans) of the resulting film showed that the film comprising the pseduocubic phase had an epitaxial relationship with the SriO3 substrate.

• 한국전기전자재료학회논문지
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• 제17권9호
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• pp.942-946
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• 2004

The crystalline and dielectric properties on Al$_2$O$_3$ filled glass frit (CaO-Al$_2$O$_3$-SiO$_2$-MgO-B$_2$O$_3$) with admixtures of TiO$_2$ have been investigated. The dielectric constant value of 7.5 ∼ 7.8, qualify factor value of 700 were obtained for glass frit : Al$_2$O$_3$(50 : 50 wt%) ceramics. Addition of TiO$_2$ less than 5 wt% slightly increased the dielectric constant from 7.8 to 8.8 due to higher dielectric constant of TiO$_2$. With increasing the amount of TiO$_2$ up to 5 wt%, the temperature coefficient of dielectric properties was improved. When the TiO$_2$ 5 wt% were added, dielectric properties were dielectric constant 8.8, quality factor 840 and the temperature coefficient of dielectric 45 ppm/$^{\circ}C$ at a sintering temperature 920$^{\circ}C$.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 춘계학술발표회 논문집
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• pp.295-295
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• 2012

The $TiO_2$ films were prepared in the $H_2SO_4$ solution containing $NH_4F$ at different anodic voltages, to compare the photocatalytic performances of titania for purification of waste water. The microstructure was characterized by a Field-emission scanning electron microscopy (FE-SEM) and X-ray diffractometry (XRD). Chemical bonding states and co-doped elements of F and N were analyzed using surface X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the co-doped $TiO_2$ films was analyzed by the degradation of aniline blue solution. From the result of diffuse reflectance absorption spectroscopy(DRS), it is indicated that the absorption edge of the F-N-codoped $TiO_2$ films shifted toward visible light area, and the photocatalytic reaction of $TiO_2$ was improved by doping an appropriate contents of F and N.

• Nano
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• 제13권11호
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• pp.1850130.1-1850130.12
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• 2018

A novel strontium titanate/binary metal sulfide ($SrTiO_3/SnCoS_4$) heterostructure was synthesized by a simple two-step hydrothermal method. The visible-light-driven photocatalytic performance of $SrTiO_3/SnCoS_4$ composites was evaluated in the degradation of methyl orange (MO) under visible light irradiation. The photocatalytic performance of $SrTiO_3/SnCoS_4-5%$ is much higher than that of pure $SrTiO_3$, $SnCoS_4$, $SrTiO_3/SnS_2$ and $SrTiO_3/CoS_2$. The $SrTiO_3/SnCoS_4$ composite material with 5 wt.% of $SnCoS_4$ showed the highest photocatalytic efficiency for MO degradation, and the degradation rate could reach 95% after 140 min irradiation time. The enhanced photocatalytic activity was ascribed to not only the improvement of visible light absorption efficiency, but also the construction of a heterostructure which make it possible to effectively separate photoexcited electrons and holes in the two-phase interface.

• 열처리공학회지
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• 제28권2호
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• pp.63-67
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• 2015

$TiO_2/Ag/TiO_2$ trilayer films were deposited with radio frequency (RF) and direct current (DC) magnetron sputtering onto the glass substrate to consider the influence of Ag interlayer on the optical properties of the films. The thickness of $TiO_2$ films was kept at 24 nm, while the thickness of Ag interlayer was varied as 5, 10, 15, and 20 nm. As-deposited $TiO_2$ single layer films show the optical transmittance of 66.7% in the visible wave-length region and the optical reflectance of 16.5%, while the $TiO_2$ films with a 15 nm thick Ag interlayer show the enhanced optical transmittance of 80.2% and optical reflectance of 77.8%. The carrier concentration was also influenced by Ag interlayer. The highest carrier concentration of $1.01{\times}10^{23}cm^{-3}$ was observed for a 15 nm thick Ag interlayer in $TiO_2/Ag/TiO_2$ films. The observed result means that an optimized Ag interlayer in $TiO_2/Ag/TiO_2$ films enhanced the structural and optical properties of the films.