• Title/Summary/Keyword: ceramic nanoparticles

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Synthesis of Monodispersed Barium Titanate Nanopowders by Alkoxide-Hydroxide Sol-Precipitation Method

  • Yoon, Song-Hak;Kim, Min-Gyu;Shin, Nam-Soo;Kim, In-Sung;Baik, Sung-Gi
    • Journal of the Korean Ceramic Society
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    • v.43 no.11 s.294
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    • pp.710-714
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    • 2006
  • Barium titanate nanoparticles were synthesized under N$_2$ atmosphere by the hydrolysis and condensation of barium hydroxide octahydrate and titanium (IV) isopropoxide. The synthesized particles were aggregates of nanosized primary particles. The primary particles of about 20-50 nm in diameter became building blocks of larger secondary particles, which are in most cases spherical in shape. The size and morphological evolution of secondary particles are strongly related to the precursor concentration. The observations suggest that formation and control of secondary particles is an essential step in the alkoxidehydroxide sol-precipitation process to obtain monodispersed barium titanate nanopowders.

The Photocatalytic Decompositions of 2-Chlorophenol on the Sn-impregnated Titania Nanoparticles and Nanotube (Sn 함침-티타니아 나노입자와 나노튜브에 놓인 2-Chlorophenol 광 분해 성능)

  • Kim, Hyun Soo;Lee, Gayoung;Park, Sun-Min;Kang, Misook
    • Journal of the Korean Ceramic Society
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    • v.49 no.5
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    • pp.461-468
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    • 2012
  • This study focuses on the difference of photocatalytic activity depending on crystal structure type of nanoparticles ($TiO_2$) and nanotubes (TNT). The photodecomposition of 2-chlorophenol on the synthesized $TiO_2$, Sn-impregnated $TiO_2$, TNT, and Snimpregnated TNT were evaluated. The characteristics of the synthesized photocatalyts, TNT, Sn/TNT, $TiO_2$, and Sn/$TiO_2$ were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-Visible spectroscopy (UV-Vis), and cyclic voltammeter (CV). The water-suspended 2-chlorophenol photodegradation over $TiO_2$ (anatase structure) catalyst was better than that over pure TNT. Particularly, the water-suspended 2-chlorophenol of 10 ppm was perfectly decomposed within 4 h over Sn/$TiO_2$ photocatalyst.

Effect of Annealing Temperature with Silver Nanoparticles Incorporation on the Electronic Structure of Poly (3, 4-ethylenedioxythiphene) : poly (styrenesulfonate) Film (은 나노입자가 함침된 Poly (3, 4-ethylenedioxythiphene) : poly (styrenesulfonate)필름의 전자 구조상태에 미치는 열처리효과 연구)

  • Wang, Seok-Joo;Lee, Cho-Young;Park, Hyung-Ho
    • Korean Journal of Materials Research
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    • v.18 no.9
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    • pp.503-506
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    • 2008
  • The effect of silver nanoparticles (NPs) incorporation on the electronic properties of poly (3, 4-ethylenedioxythiphene) : poly(styrenesulfonate) (PEDOT : PSS) films was investigated. The surface of silver NPs was stabilized with trisodium citrate to control the size of silver NPs and prevent their aggregation. We obtained ca. 5 nm sized silver NPs and dispersed NPs in PEDOT : PSS solution. Sheet resistance, surface morphology, bonding state, and work function values of the PEDOT : PSS films were modified by silver NPs incorporation as well as annealing temperature. Sodium in silver NPs solution could lead to a decrease of work function of PEDOT : PSS; however, large content of silver NPs have an effect on the increase in work function, resulting from charge localization on the silver NPs and a decrease in the number of charge-trapping-related defects by chemical bond formation.