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摘要: 采用简单的空气氧化法由实心炭微球制备中空结构的炭微球。通过场发射扫描电子显微镜、高分辨透射电子显微镜、X-射线衍射仪、拉曼光谱和热重分析仪对产物的形貌和结构进行表征。结果表明:中空炭微球的石墨化程度较低。在炭微球的空气热氧化过程中,反应温度对炭微球从实心到中空的结构演变起着关键性的作用,温度越高,中空炭微球的内径越大、壁越薄。其形成机理可认为是炭微球的曲率和结晶度协同作用的结果。亦即,实心炭微球进行热氧化时,其内部的大曲率和低结晶度更易氧化,以致形成中空炭微球。Abstract: Hollow carbon microspheres, several micrometers in diameter, were prepared from solid carbon microspheres by a simple oxidation-in-air process. The morphology and structure of these products were characterized by field-emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and thermogravimetry. Results indicate that heat treatment temperature in air plays a key role in the evolution of the cavity size and wall thickness of the hollow carbon microspheres with poor graphitization, and high heating temperature leads to a thin wall thickness and large inner diameter. A proposed formation mechanism reveals that the hollow carbon microspheres are formed as a result of the effect of curvature and crystallinity, i.e. the inner part of solid carbon microspheres has a large curvature and a low crystallinity, which is much more easily oxidized to form hollow carbon microspheres when subjected to air oxidation.
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Key words:
- Carbon microspheres /
- Oxidation /
- Hollow carbon microspheres /
- Formation mechanism
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