钴基气凝胶的制备及微观结构

Synthesis and Characterization of Cobalt-based Aerogel

以氯化钴为原料,聚丙烯酸(PAA)为模板剂制得了钴基复合气凝胶,通过场发射扫描电镜(FESEM)、高分辨透射电镜(HRTEM)、X射线衍射(XRD)、N2吸脱附以及红外谱图(FTIR)对气凝胶的结构进行了表征,结果表明:钴基复合气凝胶是由大量纳米级的球状颗粒堆积而成的,具有典型的三维网络结构,其骨架是由大量非晶态的碳层包覆的氧化钴胶体颗粒所组成的;气凝胶具有较高的比表面积为177 m2/g,孔径分布主要集中在4 nm左右,为介孔材料。通过退火处理后,钴基复合气凝胶中的有机物被完全氧化、分解,制备出了Co3O4气凝胶,其微观结构较为致密,具有立方的多晶结构,比表面积为54 m2/g,孔径分布主要集中在7 nm左右。

Cobalt-based composite aerogel was synthesized by sol-gel process and CO2 supercritical drying. The morphology of the aerogel was evaluated by field-emission scanning electron microscope （FESEM） and high-resolution transmission electron microscope （HRTEM）, which suggest that the aerogel was made up of 3-D networks and the skeleton was composed of cobalt oxide colloidal particles with amorphous carbon. The N2 adsorptiorr/desorption shows that the aerogel has high BET surface area of 177 m2/g, average pore diameter of about 4 nm, which means that the aerogel possesses the typical characteristics of mesopore. Then, the cobalt-based composite aerogel was annealed, and the crystal structure of Co304 aerogel was investigated by the XRD patterns. The N2 adsorption/desorption shows the aerogel with a surface area of about 54 m2/g and the distribution of pore-diameter of around 7 nm.