首先采用化学气相沉积法,在氙气气氛下,以脱油沥青为原料制备了炭微球(CMSs);然后用不同浓度的KMnO4溶液对CMSs进行处理,使得CMSs表面被氧化并包覆一层MnO2;最后用草酸洗涤产物,除去MnO2。通过场发射扫描电镜对CMSs氧化前后的彤貌进行观察,刚X-射线衍射对产物进行结构表征,并考察了氧化前后的CMSs在水和乙醇中的分散性。结果表明:当用0.1mol/L的KMnO4氧化改性CMSs后,CMSs表面包覆了一层Mn2,形成MnO2/CMSs复合材料。经过量的草酸进行洗涤,得到的产物在水中分散效果很好,且在乙醇中也有一定分散性。氧化后CMSs的表面存在亲水活性位点,为CMSs的进一步功能修饰奠定了基础。
Carbon microspheres (CMSs) were synthesized by chemical vapor deposition in an Ar atmosphere using deoiled asphalt as carbon source. KMnO4 aqueous solutions with different concentrations were used to oxidize the CMSs to form MnO2-coated CMSs (MnO2/CMS composites) and H2C2O4 solution was used to wash the MnO2/CMS composites to remove MnO2 to obtain oxidized CMSs. The morphology and structure of the CMSs before and after MnO2 deposition, as well as the oxidized CMSs, were characterized by field-emission scanning electron microscopy and X-ray diffraction. The dispersion of the oxidized CMSs in water and ethanol was also investigated. A uniform MnO2 nano-coating was formed on surface of the CMSs when a 0.1 mol/L KMnO4 aqueous solution was used. When an excess amount of H2C2O4 solution was used to wash away the MnO2 nanocoating, the resulting CMSs have oxygen-containing groups, such as hydroxyl, carbonyl and carboxylic, and can be well dispersed in water and partly dispersed in ethanol.