基于海藻制备超级电容器用三维多孔石墨烯

以海藻作为固相碳源,利用海藻对金属离子具有吸附性能的特点,在未进行生物质材料改性的条件下,实现海藻生物质材料对催化剂金属离子的均匀吸附.本文结合原位高温金属催化和化学活化的方法制备三维多孔石墨烯,并研究了其作为超级电容器电极材料的电化学性能.通过扫描电镜、透射电镜、X射线衍射、拉曼光谱、氮气吸附等手段对三维多孔石墨烯的形貌与结构进行表征分析.研究结果表明,制备的三维多孔石墨烯具有片层状三维网络结构,且片层较薄,并具有较高的石墨化程度,其比表面积达到1 700 m~2/g,孔径分布主要在2~10 nm.以该三维多孔石墨烯材料作为超级电容器电极材料,进行电化学性能表征,发现在较低的电压扫速下得到的比电容量为90 F/g,同时,该材料还具有较高的能量密度和功率密度.以海藻为固相碳源制备得到的三维多孔石墨烯材料在超级电容器领域具有一定的应用前景.

Three dimensional porous graphene derived from alga for supercapacitors

The alga as solid carbon source, which has adsorption characteristics for metal ions, can adsorb metal ion catalyst uniformly without the conditions of biomass material modification. Three dimensional porous graphene was synthesized by combination of high temperature metallic catalysis and chemical activation using alga as the precursor. The morphology and structure of the three dimensional porous graphene was characterized with scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman and N₂ adsorption/desorption, while its capacitive properties were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. The results showed that the porous graphene had three-dimensional network structure, with a relatively high graphitization degree and a high specific surface area of 1 700 m²/g. The internal pore size of porous graphene ranged from 2 to 10 nm. The supercapacitor based on the porous graphene showed good electrochemical capacitance (up to 90 F/g at 1 mV/s). In the two-electrode symmetric supercapacitor, relatively high energy densities and power densities could be achieved.