壳聚糖基多孔碳材料的制备及其超级电容性能

以胶态SiO₂纳米粒子为模板，壳聚糖为碳源，ZnCl2为活化剂，制备了具有不同比表面积和孔体积的氮掺杂介孔碳。采用多种表征手段对碳材料的微观形貌、比表面积和孔道结构进行了表征，探究了壳聚糖与SiO₂纳米粒子的比例以及ZnCl2活化剂对碳材料孔体积和比表面积的影响。结果表明，在未使用活化剂时碳材料(CSi-1.75)的孔体积高达4.53 cm³·g^-1，但其比表面积最小(729 m²·g^-1)；使用ZnCl₂作为活化剂制备的碳材料(CSi-1.75-Zn)比表面积为1032 m²·g^-1，但其孔体积下降到1.99 cm³·g^-1，且具有最多的吡啶氮和吡咯氮。在以6.0 mol·L^-1 KOH为电解液的三电极体系中，当电流密度为0.5 A·g^-1时，CSi-1.75-Zn的比电容为344 F·g^-1，而CSi-1.75的比电容仅为255 F·g^-1。这表明碳材料的比表面积对超级电容性能影响最大，而孔体积影响较小。电容贡献分析结果表明，相对于CSi-1.75，CSi-1.75-Zn的双电层电容和赝电容都得到了提高，这表明更大的比表面积和更多的吡啶氮和吡咯氮有利于提高碳材料的超级电容性能。

Preparation and electrochemical performance for supercapacitors of chitosan-based porous carbon materials

Nitrogen-containing mesoporous carbon with different specific surface areas and pore volumes were prepared by using colloidal silica spheres as the hard template, chitosan as a carbon precursor, and ZnCl₂ as activation agent. The morphology, surface area, and pore structure of the prepared carbons were characterized by different techniques. The influence of the ratio of silica to chitosan and the use of ZnCl₂ on the pore volume and surface area of porous carbon materials were explored. It was found that the nitrogen-doped mesoporous carbon (CSi-1.75) without using activation agent showed lowest surface area but the pore volume can reach up to 4.53 cm³·g^-1. The carbon (CSi-1.75-Zn) prepared by using ZnCl₂ as activation agent, had the larger surface area (1032 m²·g^-1) and the pore volume decreased to 1.99 cm³·g^-1 and had more pyridine-nitrogen and pyrrole-nitrogen. In the three electrodes with 6.0 mol·L^-1 KOH as the electrolyte, when the current density was 0.5 A·g^-1, the specific capacitance of CSi-1.75-Zn can reach 344 F·g^-1, while the specific capacitance of CSi-1.75 was only 255 F·g^-1. This indicates that the surface area of the carbon material had the greatest impact on the supercapacitive performance. The capacitance contribution analysis results showed that both the double-layer capacitance and pseudo capacitance of CSi1.75-Zn were improved compared with CSi 1.75, indicating that larger specific surface area and more pyridine nitrogen and pyrrole-nitrogen are conducive to improving the capacitance of carbon materials.