碳化硅衍生碳的制备及其超级电容性能

摘要

Silicon carbide precursors were synthesized by pyrolysis of polycarbosilane (PCS) at higher temperature.Subsequently,silicon carbide-derived carbons (SiC-CDCs) were obtained via chlorination of the SiC precursors at 1 000 ℃C.The microstructure and morphology of the SiC-CDCs were characterized by X-ray diffraction pattern (XRD),Raman spectra,Transmission electron microscope (TEM) and N2 adsorption-desorption method.The effects of pyrolysis temperature on the crystal phase,morphology,pore size and distribution of the SiC-CDCs were investigated and the electrochemical performances as the electrode of supercapacitors were evaluated.The results show that SiC-CDCs with larger specific surface areas and sub-nanometer pores can be successfully prepared by chlorination of SiC precursors.Meanwhile,the SiC-CDCs exhibit better specific capacitances and supercapacitive performances at different current densities.%以聚碳硅烷(PCS)为原料,通过不同温度高温热解制备碳化硅(SiC)前驱体,将得到的碳化硅前驱体在1 000℃条件下采用氯气刻蚀,成功制备了碳化硅衍生碳(SiC-CDCs).采用X-射线衍射光谱(XRD)、拉曼光谱(Raman)、透射电子显微镜(TEM)和N2吸附-脱附法等表征方法,研究了热解温度对SiC前驱体及SiC-CDCs的物相、形貌、孔结构和分布的影响;并将制备的材料作为超级电容器的电极材料,测试了其电化学性能.结果表明:采用氯气刻蚀聚碳硅烷热解生成的SiC,可以得到具有较高比表面积和亚纳米孔(＜1 nm)的SiC-CDCs;SiC-CDCs用作超级电容器的电极材料,具有较高的比电容且在不同的电流密度下均表现出良好的电容性能.