• Title, Summary, Keyword: Tin dioxide

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Characteristics of methane reforming with carbon dioxide using transition metal catalyts (전이금속 촉매를 이용한 이산화탄소와 메탄의 개질 특성)

  • Jang, Hyun Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.644-650
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    • 2021
  • This study characterized the reforming of methane with carbon dioxide, which is a major cause of global warming. The methane decomposition reaction with carbon dioxide was carried out using transition metal catalysts. The reactivity of tin was lower than that of a transition metal, such as nickel and iron. Most of the decomposition reaction occurred in the solid state. The melting point of tin is 505.03 K. Tin reacts in a liquid phase at the reaction temperature and has the advantage of separating carbon produced by the decomposition of methane from the liquid tin catalyst. Therefore, deactivation due to the deposition of carbon in the liquid tin can be prevented. Methane decomposition with carbon dioxide produced carbon monoxide and hydrogen. Ni was used to promote the catalyst performance and enhance the activity of the catalyst and lifetime. In this study, catalysts were synthesized using the excess wet impregnation method. The effect of the reaction temperature, space velocity was measured to calculate the activity of catalysts, such as the activation energy and regeneration of catalysts. The carbon-deposited tin catalyst regeneration temperature was 1023 K. The reactivity was improved using a nickel co-catalyst and a water supply.

The Synthesis Method of Tin Dioxide Nanoparticles by Plasma-Assisted Electrolysis Process and Gas Sensing Property

  • Kim, Tae Hyung;Song, Yoseb;Lee, Chan-Gi;Choa, Yong-Ho
    • Journal of Korean Powder Metallurgy Institute
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    • v.24 no.5
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    • pp.351-356
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    • 2017
  • Tin dioxide nanoparticles are prepared using a newly developed synthesis method of plasma-assisted electrolysis. A high voltage is applied to the tin metal plate to apply a high pressure and temperature to the synthesized oxide layer on the metal surface, producing nanoparticles in a low concentration of sulfuric acid. The particle size, morphology, and size distribution is controlled by the concentration of electrolytes and frequency of the power supply. The as-prepared powder of tin dioxide nanoparticles is used to fabricate a gas sensor to investigate the potential application. The particle-based gas sensor exhibits a short response and recovery time. There is sensitivity to the reduction gas for the gas flowing at rates of 50, 250, and 500 ppm of $H_2S$ gas.

Influence of Thermal Treatment on Surface Morphology of Tin Dioxide Thin Films (열처리에 따른 SnO2 박막의 표면형상)

  • Park, Kyung-Hee;Ryu, Hyun-Wook;Seo, Yong-Jin;Lee, Woo-Sun;Hong, Kwang-Jun;Park, Jin-Seong
    • Korean Journal of Materials Research
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    • v.13 no.7
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    • pp.442-446
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    • 2003
  • Tin dioxide ($SnO _2$) thin films were deposited at $375^{\circ}C$ on alumina substrate by metal-organic chemical vapor deposition. A few hillocks like a cauliflower were observed and the number of hillock on thin film surface increased with annealing temperature in air atmosphere. The oxygen content and the binding energy during air annealing at$ 500^{\circ}C$ came to close the stoichiometric $SnO_2$. The cauliflower hillocks seem to be the result of the continuous migration of the tiny grains to release the stress of an expanded grain. Sensitivity of CO gas depended on annealing temperature and increased with increasing annealing temperature.

Annealing Effect on $SnO_2$ Thin Films Properties ($SnO_2$ 박막 특성에 미치는 annealing 효과)

  • Park, Kyung-Hee;Seo, Yong-Jin;Lee, Woo-Sun;Park, Jin-Seong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.99-102
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    • 2003
  • Tin dioxide thin films were deposited at $375^{\circ}C$ on alumina substrate by metal-organic chemical vapor deposition process to find the relationship between physicochemical properties and the annealing treatments. The small grains with heat treatments grew to the bunch of grains and then showed the hillocks on the film surface. The thickness decreased with annealing treatment. The measured binding energy (BE) and branching ratio of the Sn 3d spin-orbital doublet were typical of oxidized states of Sn and the BE of the O1s core level of about 530~530.65eV also confirmed the presence of O-Sn bonds. The BE of oxygen and tin with annealing treatment shifted to higher position. O/Sn atomic ratios of films deposited at $375^{\circ}C$ for 2min and 4min were 1.99 and 2.01, respectively. The value of the atomic ratio O/Sn of films deposited at $375^{\circ}C$ for 2min changed from 1.99 to 2.45 with annealing treatment. Gas sensitivity depended on annealing temperature, the sensitivity increased with increasing annealing temperature.

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The Influence of Oxygen Gas Flow Rate on Growth of Tin Dioxide Nanostructures (이산화주석 나노구조물의 성장에서 산소가스 유량이 미치는 영향)

  • Kim, Jong-Il;Kim, Ki-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.10
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    • pp.1-7
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    • 2018
  • Tin dioxide, $SnO_2$, is applied as an anode material in Li-ion batteries and a gas sensing materials, which shows changes in resistance in the presence of gas molecules, such as $H_2$, NO, $NO_2$ etc. Considerable research has been done on the synthesis of $SnO_2$ nanostructures. Nanomaterials exhibit a high surface to volume ratio, which means it has an advantage in sensing gas molecules and improving the specific capacity of Li-ion batteries. In this study, $SnO_2$ nanostructures were grown on a Si substrate using a thermal CVD process with the vapor transport method. The carrier gas was mixed with high purity Ar gas and oxygen gas. The crystalline phase of the as-grown tin oxide nanostructures was affected by the oxygen gas flow rate. The crystallographic property of the as-grown tin oxide nanostructures were investigated by Raman spectroscopy and XRD. The morphology of the as-grown tin oxide nanostructures was confirmed by scanning electron microscopy. As a result, the $SnO_2$ nanostructures were grown directly on Si wafers with moderate thickness and a nanodot surface morphology for a carrier gas mixture ratio of Ar gas 1000 SCCM : $O_2$ gas 10 SCCM.

Structural Characteristics of $SnO_2$ Thin Films prepared by PECVD (PECVD로 제조한 $SnO_2$ 박막의 구조적 특성)

  • Lee, Jeong-Hoon;Jang, Gun-Eik;Son, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.250-251
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    • 2005
  • Tin dioxide (SnO$_2$) thin films have been prepared on Si wafer (100) by Plasma Enhanced Chemical Vapor Deposition (PECVD). SnO$_2$ thin films were prepared from mixtures of dibutyltin diacetate as a precursor, oxygen as an oxidant at 275, 325, 375, 425$^{\circ}C$, respectively. The microstructure of deposited films was characterized by X-ray diffraction and field emission scanning electron microscopy. Structural characteristics of prepared SnO$_2$ thin films were investigated with different substrate temperature. The deposition rate was linearly increased with substrate temperature. Surface morphology and uniformity of prepared thin film was excellent at 375$^{\circ}C$ and grain size was averagely 25nm.

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Preparation, Characterization and Catalytic Activity of Tin Dioxide and Zero-Valent Tin Nanoparticles

  • Pouretedal, H.R.;Shafeie, A.;Keshavarz, M.H.
    • Journal of the Korean Chemical Society
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    • v.56 no.4
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    • pp.484-490
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    • 2012
  • The tin (IV) oxide nanoparticles are prepared by controlled precipitation method and calcined at temperatures of $200-600^{\circ}C$. The prepared $SnO_2$ nanoparticles characterized by XRD patterns, TEM image, IR and UV-Vis spectra. The XRD patterns and TEM image show the tetragonal structure and spherical morphology for $SnO_2$ nanoparticles, respectively. The photocatalytic activity of the prepared $SnO_2$ nanoparticles studied in degradation reaction of methylene blue (MB). The results show the size of nanoparticles, band-gap energy and photocatalytic activity of $SnO_2$ depends on the calcinations temperature. The $SnO_2$ nanoparticles calcined at $500^{\circ}C$ indicated the highest photoreactivity. Also, the zero-valent tin (ZVT) nanoparticles with tetragonal structure are prepared by a reducing agent and used as a catalyst in degradation of MB. In basic pH of 11, the degradation >95% of MB at time 150 min obtained at presence of ZVT nanoparticles.

A simple route for synthesis of SnO2 from copper alloy dross

  • Lee, Jung-Il;Lee, Bo Seul;Lee, Ji Young;Shin, Ji Young;Kim, Tae Wan;Ryu, Jeong Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.24 no.2
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    • pp.84-87
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    • 2014
  • Separation/recovery of valuable metals such as zinc, nickel or tin from copper alloy dross has recently attracted from the viewpoints of environmental protection and resource recycling. In this study, preliminary investigation on separation of tin (Sn) from copper alloy dross using selective dissolution method was performed. The tin in the copper alloy dross did not dissolve in an aqueous nitric acid solution which could allow the concentration/separation of tin from the copper alloy dross. Precipitation of tin as $H_2SnO_3$ (meta stannic acid)occurred in the solution and transformed to tin dioxide ($SnO_2$) after drying process. The dried sample was heat-treated at low temperature and its crystal structure, surface morphology and chemical composition were investigated.