中文摘要：

为了改善碳球表面惰性，利用溶胶一凝胶法在碳球表面包覆二氧化硅，考察了介质条件对包覆效果的影响。通过场发射扫描电子显微镜和透射电子显微镜等手段对不同介质中得到的样品进行对比分析表征。结果表明，碱性介质更有利于二氧化硅在碳球表面的包覆，所得复合物球表面光滑、包覆层厚且厚度均一，焙烧除去碳球核后得到空心二氧化硅球，并分析了碳球表面二氧化硅的包覆机理。

英文摘要：

To improve the surface property of carbon spheres, silica was coated on the surface of carbon sphere by sol-gel process. Effect of reaction medium on surface coating of carbon spheres with silica was investigated. Characterization by field emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction analysis indicates that silica is prone to coat on the surface of carbon spheres in alkaline medium, giving CSs-SiO2 composite spheres with smooth surface and a coating of 50nm in thickness, which is thicker than that in acid medium. Hollow silica spheres were prepared after the carbon spheres were removed by high temperature calcination. The coating mechanism of silica was also discussed.