• Title/Summary/Keyword: Layered double hydroxide

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A Literature Study on the Development of Cementitious Materials using a Layered Double Hydroxide (층상이중수산화물(Layered Double Hydroxides)을 활용한 시멘트계 재료 개발에 관한 문헌조사 연구)

  • Lee, Seung-Yeop;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.11a
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    • pp.107-108
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    • 2015
  • Layered Double Hydroxides is known as a hydrotalcite-like material. It is a type of anionic clay with planar structure. It is composed of layer structure which is able to exchange anion between two layers which includes divalent ion and trivalent ion. Therefore, layered double hydroxide is applicable for eliminating harmful heavy metals and anionic substances which exist in the concrete. Because it is also able to be used as catalyst and has high possibility of utilization, It is getting an large amount of attention recently. In this study, an analysis on the structure of the layerd double hydroxide (LDH) which is possible to bind the anion was carried out.

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Transition Metal-Based Layered Double Hydroxides for Oxygen Evolution Reaction Catalysts (전이금속 이중층 수산화물 기반 산소발생반응 촉매 연구 동향)

  • Da-Un Han;Gyeongbae Park
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.4
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    • pp.358-373
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    • 2024
  • Oxygen evolution reaction is a critical bottleneck for the development of efficient electrochemical hydrogen production because of its sluggish reaction. Among various catalysts, transition metal-based layered double hydroxide has drawn significant attention due to their excellent catalytic properties and cost-effectiveness. This paper begins with basic crystal structures, and then conventional adsorbate evolution mechanism of layered double hydroxide. Strategies for enhancing catalytic properties based on adsorbate evolution mechanism and lattice oxygen mechanism that could surpass theoretical limit of adsorbate evolution mechanism are discussed. This paper ends with a brief discussion on the challenges and future directions of layered double hydroxide-based oxygen evolution reaction catalysts.

Intercalation of Functional Organic Molecules with Pharmaceutical, Cosmeceutical and Nutraceutical Functions into Layered Double Hydroxides and Zinc Basic Salts

  • Hwang, Seong Ho;Han, Yang Su;Choe, Jin Ho
    • Bulletin of the Korean Chemical Society
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    • v.22 no.9
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    • pp.1019-1022
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    • 2001
  • Negatively charged functional organic molecules such as retinoic acid, ascorbic acid, indole acetic acid, citric acid, salicylic acid, acidic dye (indigo carmine, Food Blue 1) are intercalatively encapsulated by zinc basic salt (hydrozincite) and layered double hydroxide. Such functional organic-inorganic nanohybrids are realized via coprecipitation reaction involving simultaneous formation of layered inorganic lattice and intercalation of anionic species. The heterostructural nature of these nanohybrids, their particle morphology and textural characterizations are mainly discussed on the basis of Powder X-ray Diffraction and Field Emission Scanning Electron Microscopy results.

The structure of intercalation compound between a layered double hydroxide and an ethyl orange (층상이중수산화물과 에틸오렌지의 삽입화합물의 구조)

  • Jung, Woo-Chan;Huh, Young-Duk
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.1
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    • pp.137-142
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    • 1997
  • We synthesized the intercalation compound between a layered double hydroxide and an ethyl orange. The orientation of the intercalated ethyl orange into the layered double hydroxide was investigated. The molecular plane of the ethyl orange and its N=N axis lie nearly perpendicular to the hydroxide layers with an antiparallel pattern.

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Hydrothermal Synthesis and Exfoliation of Mg/Al Layered Double Hydroxide with Tailored Aspect Ratio (수열 합성 및 박리에 의한 Mg/Al 층상 이중 수산화물의 종횡비 제어)

  • Hwang, Sung-Hwan;Kim, Donghyun;Kim, Yewon;Jung, Hyunsung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.12
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    • pp.822-827
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    • 2017
  • Mg/Al layered double hydroxide with two-dimensional (2D) nanostructures was synthesized by a hydrothermal technique. The morphology and aspect ratio of $Mg_4Al_2(OH)_{14}3H_2O$ were controlled by the concentration and kinds of the hydrolysis agent, and temperature. The aspect ratio of $Mg_4Al_2(OH)_{14}3H_2O$ layered double hydroxides with the 2D hexagonal crystal structure was tailored from about 12.6 to about 45.7. The intercalated $CO{_3}^{2-}$ anions of the synthesized 2D $Mg_4Al_2(OH)_{14}3H_2O$ layered double hydroxides were exchanged to $NO_3{^-}$ anions. The bulk 2D $Mg_4Al_2(OH)_{14}3H_2O$ layered double hydroxides with the increased space between two layers due to the anion exchange were exfoliated in a formamide solution. The aspect ratio of the exfoliated 2D $Mg_4Al_2(OH)_{14}3H_2O$ layered double hydroxides increased to 570.3.

The structure and synthesis of intercalation compound between a layered double hydroxide and an organic compound (유기화합물이 삽입된 층상이중수산화물의 합성과 구조)

  • 우은경;허영덕
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.1
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    • pp.36-41
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    • 1998
  • Intercalation compounds of alkyl sulfonates into layered double hydroxides (LDH) have been directly synthesized. From the X-ray diffraction data and the alkyl sulfonates size, the orientation of the intercalated alkyl sulfonate into the layered double hydroxide was determined. The intercalated alkyl sulfonate is arranged with molecular chain perpendicular to the hydroxide layer with an antiparallel pattern.

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Incorporation of Antibacterial Natural Extract into Layered Double Hydroxide through Memory Effect for Antibacterial Materials (금속이중층수산화물의 메모리효과를 이용한 항균 천연소재의 담지 및 항균소재의 개발)

  • Kim, Hyeong-Jun;Jeong, Do-Gak;O, Je-Min
    • Ceramist
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    • v.22 no.3
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    • pp.301-315
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    • 2019
  • We prepared hybrids between layered double hydroxide (LDH) and natural plant extract such as Peaonia suffruticosa Andrews (PS) and Peaonia Japonica (PJ) which was confirmed anti-bacterial activity through paper disc diffusion assay. According to X-ray diffractometer, scanning electron microscope, zeta-potential measurement and quantification of extract loading amount in hybrids, we confirmed that similar amount of PS and PJ loaded on inter-particle pore of LDH with partial adsorption on surface of LDH through reconstruction process. We also evaluated the bacterial colony forming inhibition of PS extract, PJ extract, PS-LDH and PJ-LDH hybrids against Escherichia coli as gram negative bacterium and Bacillus subtilis as gram positive bacterium, suggesting that both hybrids have enhanced anti-bacterial activity compared with extract itself.

Remarkable Stability of Graphene/Ni-Al Layered Double Hydroxide Hybrid Composites for Electrochemical Capacitor Electrodes

  • Lee, Jeong Woo;In, Su-Il;Kim, Jong-Duk
    • Journal of Electrochemical Science and Technology
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    • v.4 no.1
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    • pp.19-26
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    • 2013
  • Graphene/Ni-Al layered double hydroxide (LDH) hybrid materials were synthesized by a hydrothermal reaction. Hexagonal Ni-Al LDH particles nucleated and grew on graphene sheets, thus preventing restacking of the graphene sheets and aggregation of the Ni-Al LDH nanoparticles upon drying. Electrode made from the graphene/Ni-Al LDH hybrid materials showed a substantial improvement in electrochemical capacitance relative to those made with pure Ni-Al LDH nanoparticles. In addition, the graphene/Ni-Al LDH hybrid composite materials showed remarkable stability after 4000 cycles with over 100% capacitance retention. These materials are thus very promising for use in electrochemical capacitor electrodes.

3D Hierarchical Heterostructure of TiO2 Nanorod/Carbon Layer/NiMn-Layered Double Hydroxide Nanosheet

  • Zhao, Wei;Jung, Hyunsung
    • Journal of the Korean institute of surface engineering
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    • v.51 no.6
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    • pp.365-371
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    • 2018
  • 1D core-shell nanostructures have attracted great attention due to their enhanced physical and chemical properties. Specifically, oriented single-crystalline $TiO_2$ nanorods or nanowires on a transparent conductive substrate would be more desirable as the building core backbone. However, a facile approach to produce such structure-based hybrids is highly demanded. In this study, a three-step hydrothermal method was developed to grow NiMn-layered double hydroxide-decorated $TiO_2$/carbon core-shell nanorod arrays on transparent conductive fluorine-doped tin oxide (FTO) substrates. XRD, SEM, TEM, XPS and Raman were used to analyze the obtained samples. The in-situ fabricated hybrid nanostructured materials are expected to be applicable for photoelectrode working in water splitting.