一步法合成具有二级孔道的有序介孔碳材料及其超电容性能研究

One-step prepartion of ordered mesoporous carbon with secondary pore structure and its supercapacitance characteristics

以酚醛树脂低聚物为碳前驱体,三嵌段共聚物F127为模板剂,在此过程中加入正硅酸乙酯为硅源,900℃下炭化得到具有介孔结构的碳-SiO2复合物,除SiO2后得到具有二级孔道结构的介孔碳材料。对样品进行透射电子显微镜、N2吸附-脱附表征,并利用循环伏安以及恒电流充放电研究了样品的超电容性能。结果表明,样品具有二级孔道结构,BET比表面积为1657.6m2.g-1,比电容值161.3F.g-1。相比于单一孔道的介孔碳材料,二级孔道结构的介孔碳的循环伏安曲线更接近于矩形,比电容值有了很大提高,随着放电电流的增大其比电容值衰减率更小。

Ordered mesoporous carbon-SiO2 compound was prepared via co-assembly method, wherein resol was used as carbon precursor, tetraethyl orthosilicate was used as SiO2 precursor, and triblock copolymer Pluronic F127 was used as template. Carbonization was carried out in a tubular furnace at 900℃ for 3 h under N2 flow and mesoporous carbon with secondary pore structure was obtained after removal of SiO2. The as-prepared sample was characterized by transmission electron microscopy, nitrogen isotherm adsorption-desorption measurement, cyclic voltammetry and constant current charge-discharge. The results indicated that ordered mesoporous carbon possessed a high BET specific surface area of 1657.6m^2 · g^-1 and a specific capacitance of about 161.3F · g^- 1. The electrochemical performance was enhanced much more than the common mesoporous carbon material. Compared with the mesoporous carbon material with the single pore channel, the cyclic voltammetry curve of mesoporous ca＇rbon with secondary pore structure was closer to rectangular, the specific capacitance value was greatly improved and the decreasing rate of the capacitance was lower with increasing the discharge current capacitance.