Phase and Morphology Evolution of Manganese Oxides during Thermal Treatment

Yu Cheng Zhao; Sa Li; Chang An Wang

doi:10.4028/www.scientific.net/KEM.697.322

Paper Titles

SiO₂-Coated Fe-Ni Alloy Core–Shell Structures Synthesized by a Facile Chemical Method
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The Role of Aluminium Source (Al₂O₃/AlN) in the Synthesis of the Ca-α-SiAlON:Eu²⁺ Phosphor
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Synthesis and Up-Conversion Luminescent Properties of Na(Y_1.5Na_0.5)F₆ Hexagonal Prism
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Phase and Morphology Evolution of Manganese Oxides during Thermal Treatment
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Electrical Properties of Y_0.06Sr_0.94Ti_0.6Fe_0.4O_3-δ-YSZ Composites as Electrode Materials
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Preparation and Performance of Monazite Coating on Woven Alumina Ceramic Cloths
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Effect of Al Powder Content on Performance of MgO-Al₂O₃ Composite at 1700°C under N₂ Atmosphere
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Effect of the Addition of Al Power on the Microstructure and Phase Constitution of Al₂O₃-MgO Composites Sintered at 1700°C under N₂ Atmosphere
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HomeKey Engineering MaterialsKey Engineering Materials Vol. 697Phase and Morphology Evolution of Manganese Oxides...

Phase and Morphology Evolution of Manganese Oxides during Thermal Treatment

Abstract:

Core-shell structure with inner carbon spheres and outer MnO₂ layer was successfully prepared in this study. Thermal treatment was further conducted to remove the carbon cores to get hollow MnO₂ sphere. However, it was surprisingly found that the original MnO₂ particles turn nanorods. Moreover, it is believed that the appearance of such one-dimensional morphology attributes to the fact that the original irregularly shaped particles of amorphous MnO₂ change to mainly Mn₃O₄ fibers as a result of exposure to open air at room temperature and the fibers would convert to pyrolusite MnO₂ with heat treatment. Continuous heating would induce phase transformation from MnO₂ to Mn₃O₄ takes place at 900°C. Based on the XRD, SEM, TEM and TG-DSC analysis, we believe that the K⁺ intercalated into the MnO₂ tunnels stabilizes the nanorods structure and prevents the tunnels from collapse.

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Periodical:

Key Engineering Materials (Volume 697)

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322-326

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https://doi.org/10.4028/www.scientific.net/KEM.697.322

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Online since:

July 2016

Authors:

Yu Cheng Zhao, Sa Li, Chang An Wang*

Keywords:

Hollow Spheres, Mn₃O₄, MnO₂, Nanorod, Phase Transformation

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