• 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.

• Korean Chemical Engineering Research
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• 제51권4호
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• pp.518-522
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• 2013

사이클로헥사논은 나일론의 단량체로 사용되는 카프로락탐의 원료로 중요한 중간체이며 사이클로헥사놀의 탈수소화반응을 통해 합성된다. 본 연구에서는 탈수소화 반응에 적용하기 위한 촉매로 다양한 메조기공을 가진 금속 산화물(meso-$WO_3$, meso-$TiO_2$, meso-$Fe_2O_3$, meso-CuO, meso-$SnO_2$, meso-NiO)을 나노 복제법에 의해 합성하였다. 그 결과 meso-$WO_3$ >> meso-$Fe_2O_3$ > meso-$SnO_2$ > meso-$TiO_2$ > meso-NiO > meso-CuO 순서로 촉매 활성이 나타났으며, 그 중 meso-$WO_3$가 가장 높은 촉매 활성을 보임을 알 수 있었다. 따라서 사이클로헥사놀을 이용한 탈수소화 반응에 meso-$WO_3$의 폭넓은 응용 가능성을 확인하였다.

• 한국주조공학회지
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• 제20권3호
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• pp.208-215
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• 2000

The mechanical properties and corrosion resistance of Ti alloys for medical implants have been investigated. Ti, Ti-15Sn-4Nb and Ti-15Sn-4Nb-2Zr alloys were melted in arc furnace and the corrosion resistance of Ti alloys was evaluated by anodic polarization test. The microstructure and mechanical properties of Ti alloys were analysed by optical microscope, hardness and tensile tester. The tensile strength of the pure-Ti improved by addition of Sn and Nb and Ti-15Sn-4Nb alloy showed better Rockwell hardness compared with pure Ti. However, there was no significant difference in corrosion resistance between thoseTi-alloys made of Pure-Ti and Ti-15Sn-4Nb alloy. The passive films on the Ti-15Sn-4Nb alloy in air atmosphere consisted of $TiO_2$, SnO and NbO as demonstrated by X-ray photoelectron spectroscopy(XPS)

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.141-144
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• 2009

In this study, used simplest sandwich cells containing $Ru2^+$ liquid electrolytes in order to clarify the role of nanoporous $TiO_2$ electrodes. And, the cell structure is as follow: $F:SnO_2$ glass/ nanoporous $TiO_2$/ tris(2,2'-bipyridy)ruthenium(ll) colplex [$Ru(bpy)_3(PF_6)_2$] in acetonitrile/ $F:SnO_2$ glass. The result, we found that ECL intensities increased rapidly by use of cathodes with nanoporous $TiO_2$ layers. And, porous $TiO_2$ electrodes were confirmed to be efficient for ECL devices as well as solar cell devices. It is thought that the increases in the ECL intensities may be associated with both formation of $Ru^+$ in porous $TiO_2$ electrodes and the process taking place after reduction of $Ru^+$ which occurs in the nanoporous electrodes.

• 센서학회지
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• 제6권6호
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• pp.476-482
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• 1997

주성분 분석 및 역전달 인공 신경망의 패턴 인식 기법과 산화물 반도체 가스센서 어레이를 사용한 소형 전자코 시스템을 제작하여 그 특성을 평가하였다. 센서 어레이로서 Pd가 첨가된 $WO_{3}$, Pt가 첨가된 $SnO_{2}$, $TiO_{2}-Sb_{2}O_{5}-Pd$가 첨가된 $SnO_{2}$, $TiO_{2}-Sb_{2}O_{5}-Pd$가 첨가된 후 Pd 코팅층이 형성된 $SnO_{2}$, $Al_{2}O_{3}$가 첨가된 ZnO 및 $PdCl_{2}$가 첨가된 $SnO_{2}$ 등의 6가지 조성의 감지재료가 사용되었다. 전자코 시스템 하드웨어는 CPU로서 16bit의 Intel 80c196kc, 시스템 동작 프로그램의 저장을 위한 EPROM, 인공 신경망의 최적화된 가중치의 다운로딩을 위한 EEPROM, 가스농도의 결과 표시를 위한 LCD 등으로 구성하였다. 시스템의 성능 평가를 위해 자동차에서 배출되는 환경오염 물질인 CO/HC 가스(CO 0%/HC 0 ppm 에서 CO 7.6%/HC 400 ppm 까지 범위의 26가지 CO/HC 혼합가스 패턴)에 대한 인식 실험 결과 우수한 특성을 얻을 수 있었다.

• 멤브레인
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• 제6권2호
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• pp.101-108
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• 1996

반도성 세라믹 광촉매 막 반응기(membrane reactor)에 의한 난분해성 유독 유기물질의 효율적인 분해공정을 개발하기 위한 기초 연구로서 $TiO_{2}$ 광촉매 막의 전기화학 반응에 의한 개미산(formic acid)의 산화/분해 효율성에 대해 연구하였다. 막 반응기는 용액의 여과(filtration)와 광전기화학 반응에 의한 유기물의 광분해를 동시에 수행할 수 있도록 제작되었다. 복합막의 담체임과 동시에 전극의 역할을 할 수 있는 전기 전도성 $SnO_{2}$ 또는 stainless steel 다공성 튜브상에 pH가 1.45인 $TiO_{2}$ 졸을 졸-겔 침지 코팅하여 광촉매 복합막을 제조하였으며 광원으로는 365 nm 파장을 갖는 UV를 사용하였다. $TiO_{2}$ 광촉매 막의 전기화학 반응에 의한 개미산의 산화효율은 전극에 걸어주는 전압과 반응시간에 따라 증가하였으나 투과량(flux)에는 거의 무관하였다. $TiO_{2}/SnO_{2}$ 복합막을 사용한 경우 외부 전압을 27V 걸어주었을때 77% 정도의 산화효율을 얻을 수 있었으며 $TiO_{2}$/stainless steel 복합막에서는 90% 이상이었다. 광촉매 전기화학 반응을 이용함으로써 높은 투과량하에서도 개미산의 산화효율을 단순한 $TiO_{2}$ 광촉매 반응에서 보다 6~7배 가량 증진시킬 수 있었다.

• 한국세라믹학회지
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• 제36권9호
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• pp.915-922
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• 1999

Microwave dielectric properties and far infrared reflectivity spectra of the (Zr0.8Sn0.2)TiO4 ceramics were inves-tigated with the various cooling rate. Dielectric constant was nearly same value while the unloaded Q value was largely affected by cooling rate. The Q.f of 42,140 at 7 GHz was obtained for the specimens with cooling rate of 1$^{\circ}C$/min. The effect of the cooling rate on the change of the ionic the electronic polarization and the intrinsic microwave loss of the specimens were investigated by the infrared reflectivity spectra from 50 to 4000cm-1 which were calculated by Kramers-Kroning analysis and the classical oscillator model. The relative tendency of microwave dielectric properties of the specimens calculated from the relfectivity data were in good agreement with the results by the post resonant method.

• 한국세라믹학회지
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• 제55권4호
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• pp.368-375
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• 2018

This study deals with the color formation of ceramic pigment in the $TiO_2$-SnO-ZnO system. We designed compounds to control the color formation depending on the composition using the Design of Experiment. The color coordinate values of synthesized pigments, $L^*a^*b^*$ were measured and statistically analyzed color for changing elements depending on its composition. The relationship between the major crystalline phases and chromaticity was examined using XRD, and the oxidation states of each element were analyzed by XPS. The synthesized pigments based on the compound design exhibited various color changes ranging from yellow-orange to green-blue and brown. The statistical analysis on the spectrophotometer results shows that $a^*$ and $b^*$ values decreased with $TiO_2$ content, and increased with SnO content. Yellow-orange color was detected with the main peak of SnO, and the green-blue color developed with the main peak of $Zn_2TiO_4$. The $a^*$ and $b^*$ values increased with increased SnO peak intensity, and decreased with increased $Zn_2TiO_4$ peak intensity. The results revealed that pigment color formation was influenced by changes in the main crystalline phases and crystalline intensity. However, XPS analysis of the oxidation states of each element showed little correlation with the pigment chromaticity result.

• 한국재료학회지
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• 제25권9호
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• pp.455-461
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• 2015

SnS-$TiO_2$ nanocomposites are synthesized using simple, cheap, and less toxic $SnCl_2$ as the tin (II) precursor. The prepared nanoparticles are characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-Vis diffuse reflectance spectra (DRS). The XRD and TEM results indicate that the prepared product has SnS nanoparticles and a grain diameter of 30 nm. The DRS demonstrate that SnS-$TiO_2$ possesses the absorption profile across the entire visible light region. The generation of reactive oxygen species is detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). It is found that the photocurrent density and photocatalytic effect increase with the modified SnS. Excellent catalytic degradation of Texbrite BA-L (TBA) solution is observed using the SnS-$TiO_2$ composites under visible light irradiation. It is proposed that both the strong visible light absorption and the multiple exciton excitations contribute to the high visible light photocatalytic activity.

• 센서학회지
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• 제18권3호
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• pp.217-221
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• 2009

Different methods of material engineering, used for improvement of solid state gas sensors parameters are reviewed in this report. The wide possibilities of material engineering in optimization of gas sensing properties were demonstrated on the example of $SnO_2,\;TiO_2\;and\;In_2O_3$-based sensors.