珊瑚状氮掺杂多孔碳的制备及其超电容性能

在三聚氰胺为氮源、碳酸钾为活化剂的条件下,由菜籽饼制得了珊瑚状氮掺杂分级多孔碳(CNPCs)。采用场发射扫描电子显微镜、透射电子显微镜、X射线光电子能谱、氮吸脱附等表征手段,研究了三聚氰胺的用量对CNPCs微观形貌、组成及孔隙结构的影响。结果表明,当三聚氰胺的用量为2 g时,所得CNPC2的比表面积达2050 m2·g-1。以6 mol·L-1KOH为电解液,在0.05 A·g-1的电流密度下,CNPCs的比容可达274 F·g-1;当电流密度为50 A·g-1时,CNPCs的比容为169 F·g-1,显示了优异的倍率性能。经过10000次充放电测试后,比容保持率达96%,展现了良好的循环稳定性。此工作为从生物质大规模生产高性能储能用多孔碳材料提供了一种简单、绿色的方法。

Preparation of coral-like nitrogen-doped porous carbons and its supercapacitive properties

Under the condition of melamine as the nitrogen source and potassium carbonate as the activator, coral-like nitrogen-doped graded porous carbons (CNPCs) were prepared from rapeseed cake. Field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption and desorption techniques were used to study the effects of melamine dosage on the morphology, composition and pore structure of CNPCs. The results show that the as-prepared CNPC₂ has a high surface area up to 2050 m²·g^-1 when the dosage of melamine is 2 g. The specific capacitance of CNPCs is up to 274 F·g^-1 at a current density of 0.05 A·g^-1 in 6 mol·L^-1 KOH electrolyte. As the current density increases to 50 A·g^-1, the specific capacitance of CNPCs retains 169 F·g^-1, showing excellent rate performance. After 10000 charge and discharge cycles, the capacitance retention is 96%, demonstrating good cycle stability. This work provides a simple, green method for the mass production of high-performance porous carbon materials for energy storage from biomass.