• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1199-1204
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• 2013

Nanocomposites consisting of Sn nanoparticles and graphene oxide (GO) were electrophoretically deposited onto Cu current collectors that was used for anodes in Li ion batteries (LIBs). In order to optimize the electrochemical performance of nanocomposites as an anode material by controlling the oxygen functionality, the GO was subjected to $O_3$ treatment prior to electrophoretic deposition (EPD). During thermal reduction of the GO in the nanocomposites, the Sn nanoparticles were reduced in size, along with the formation of SnO and/or $SnO_2$ at a small fraction, relying on the oxygen functionalities of the GO. The variation in the duration of time for the $O_3$ irradiation resulted in a small change in total oxygen content, but in a significantly different fraction of each functional group in the GO, which influenced the Sn nanoparticle size and the amount of SnO (and/or $SnO_2$). As a result, the EPD films prepared with the GO that possessed the least amount of carboxylic groups (made by treating GO in an $O_3$ environment for 3 h) showed the best performance, when compared with the nanocomposites composed of untreated GO or GO that was $O_3$-treated for a duration of less than 3 h.

• 한국세라믹학회지
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• 제53권1호
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• pp.122-127
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• 2016

Tin oxide ($SnO_2$) nanoparticles have been synthesized by solution combustion method using citric acid as a fuel. The oxide to fuel ratio has been varied to obtain ultrafine nanoparticles with better surface area; such particles will be useful in many applications. With this synthesis method, spherical particles are formed having a particle size in the range of 11-30 nm and BET surface area of ~ $24m^2/g$. The degree of agglomeration of $SnO_2$ nanoparticles has been calculated.

• 한국분말재료학회지
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• 제21권5호
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• pp.377-381
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• 2014

This work describes the coloration, chemical stability of $SiO_2$ and $SnO_2$-coated blue $CoAl_2O_4$ pigment. The $CoAl_2O_4$, raw materials, were synthesized by a co-precipitation method and coated with silica ($SiO_2$) and tin oxide ($SnO_2$) using sol-gel method, respectively. To study phase and coloration of $CoAl_2O_4$, we prepared nano sized $CoAl_2O_4$ pigments which were coated $SiO_2$ and $SnO_2$ using tetraethylorthosilicate, $Na_2SiO_3$ and $Na_2SiO_3$ as a coating material. To determine the stability of the coated samples and their colloidal solutions under acidic and basic conditions, colloidal nanoparticle solutions with various pH values were prepared and monitored over time. Blue $CoAl_2O_4$ solutions were tuned yellow color under all acidic/basic conditions. On the other hand, the chemical stability of $SiO_2$ and $SnO_2$-coated $CoAl_2O_4$ solution were improved when all samples pH values, respectively. Phase stability under acidic/basic condition of the core-shell type $CoAl_2O_4$ powders were characterized by transmission electron microscope, X-ray diffraction, CIE $L^*a^*b^*$ color parameter measurements.

• 센서학회지
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• 제21권6호
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• pp.395-401
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• 2012

The bond strength of three types of $TiO_2$ coatings onto fluorine-doped $SnO_2$ (FTO) glass was investigated with the aid of a tape test according to ASTM D 3359-95. Transmittance was then measured using an UV-vis spectrophotometer in the wavelength range of 300 nm to 800 nm to evaluate the extent of adhesion of $TiO_2$ nanorods/nanoparticles on FTO glass. A sharp interface between the coating layer and the substrate was observed for single $TiO_2$ coating ($TiO_2$ nanorods/FTO glass), which may be detrimental to the bonding strength. In multicoating sample ($TiO_2$ nanorod/$TiO_2$ nanoparticle/$TiO_2$ nanoparticle/FTO glass), the tape test was not performed due to severe peeling-off prior to the test. On the other hand, the dual coating sample ($TiO_2$ nanorod/$TiO_2$ nanoparticle/FTO glass) showed minimum variation of transmittance (4%) after the test, suggesting that the topcoat adheres well with the FTO substrate due to the presence of the $TiO_2$ nanoparticle buffer layer. The use of a $TiO_2$ nanorod electrode layer with good adhesion may be attributed to the excellent dye sensitized solar cell performance.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.1999-2003
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• 2014

Indium tin oxide ($In_2Sn_{1-x}O_{5-y}$) nanoparticles were synthesized by hydrothermal method from stable indium tin acetylacetone complexes and postannealing at $600^{\circ}C$. The absence of chlorine ions shortened the synthesis process, decreased the particle agglomeration and improved the particle purity. The introduced complexing ligand acetylacetone decreased the obtained nanoparticle size. The improved powder properties accelerated the sintering of the $In_2Sn_{1-x}O_{5-y}$ nanoparticles and reached a relative density of 96.4% when pressureless sintered at $1400^{\circ}C$.

• 반도체공학회 논문지
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• 제1권1호
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• pp.9-13
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• 2023

본 연구에서는 SnO₂ 나노입자와 Pd 금속의 이중층으로 구성된 촉매층을 갖는 AlGaN/GaN 이종접합 기반의 상온동작 수소센서를 제작하여 해당 센서의 안정성 개선 연구를 수행하였다. 제작된 센서를 고온 환경이 아닌 상온에서 수소에 노출 및 차단을 반복하며 동작 시켰을 때 시간에 따라 대기전류가 감소하는 불안정한 전류 드리프트 (current drift) 현상이 발생하였지만, 자외선 (UV) 조사를 함께 진행하면서 반복 측정을 하였을 때 해당 불안정성의 가시적인 개선 효과를 이루었다.

• 공업화학
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• 제29권6호
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• pp.710-715
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• 2018

본 연구에서는 자성을 이용하여 재수득이 가능한 광 촉매 물질인 $ZnFe_2O_4@SnO_2@TiO_2$ core-shell nanoparticles (NPs)를 3단계 과정을 통해 합성하였다. 구조적 특성은 X-ray diffraction (XRD) 분석으로 확인하였다. Spinel 구조의 $ZnFe_2O_4$와 tetragonal 구조의 $SnO_2$와 anatase 구조의 $TiO_2$가 합성된 것을 확인하였다. 합성한 물질의 자기적 성질은 vibrating sample magnetometer (VSM)으로 확인하였다. Core 물질인 $ZnFe_2O_4$의 포화자화 값은 33.084 emu/g으로 확인하였다. $SnO_2$와 $TiO_2$층의 형성의 결과, 두께 증가로 인한 자성은 각각 33, 40% 감소하였으나 재수득이 가능한 충분한 자성을 가지는 것을 확인하였다. 합성된 물질의 광 촉매 효율은 methylene blue (MB)를 사용하여 측정하였다. Core 물질의 효율은 4.2%로 확인하였고 $SnO_2$와 $TiO_2$ shell 형성의 결과 각각 73%와 96%로 증가하였고 높은 광 촉매 효율을 가지는 것을 확인하였다. 또한 항균 특성은 대장균(E. Coli)과 황색포도상구균(S. Aureus)을 사용하여 억제 영역을 확인하였다. Shell이 형성되면서 더 넓은 억제 영역이 형성되었고 이는 광 촉매 효율을 측정한 결과와 일치하는 것을 확인하였다.

• 전기전자학회논문지
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• 제13권4호
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• pp.37-42
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• 2009

본 연구에서는 졸겔법으로 ZnO, 수열합성법으로 $SnO_2$ 나노분말을 제조하고 이들 나노분말에 Pd, Ru 등의 촉매를 첨가하였다. MEMS 기술로 제작된 히터 및 전극 구조 위에 나노 감지 분말을 도포하여 CO and $NO_2$ 가스 센서를 제작하였다. 0.1 wt% Pd 도핑된 $SnO_2$ 가스센서와 Ru 도핑된 ZnO 가스 센서는 각각 CO 30 ppm, $NO_2$ 1 ppm의 낮은 농도에서도 높은 감지 특성을 보였다.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.185-186
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• 2009

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.913-918
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• 2014

Five mol % tungsten-doped tin oxide ($W_{0.05}Sn_{0.95}O_2$, TTO5) was prepared by co-precipitation of $SnCl_4{\cdot}5H_2O$ and $WCl_4$, followed by calcination at $1000^{\circ}C$. The as-prepared TTO5 was in the pure cassiterite phase with a particle size of ~50 nm and optical bandgap of 2.51 eV. Herein it was applied for the formation of TTO5/$TiO_2$ heterojunctions by covering the TTO5 surface with $TiO_2$ by sol-gel method. Under visible-light irradiation (${\lambda}{\geq}420$ nm), TTO5/$TiO_2$ showed a significantly high photocatalytic activity in removing gaseous 2-propanol (IP) and evolving $CO_2$. It is deduced that its high visible-light activity is caused by inter-semiconductor holetransfer between the valence band (VB) of TTO5 and $TiO_2$, since the TTO5 nanoparticle (NP) exhibits the absorption edge at ~450 nm and its VB level is located more positive side than that of $TiO_2$. The evidence for the hole-transport mechanism between TTO5 and $TiO_2$ was also investigated by monitoring the holescavenging reaction with 1,4-terephthalic acid (TA).