猕猴桃果皮制备杂原子掺杂多孔碳材料及其超电性能研究

Heteroatom co-doped porous carbons derived from Kiwifruit peel for supercapacitor electrodes

果蔬企业在生产过程中会产生大量的果皮,这些废弃物目前还没有得到有效利用。本文以废弃猕猴桃果皮为原料,以氢氧化钾为活化剂,制备了杂原子掺杂多孔碳。通过扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、X射线衍射(XRD)、拉曼光谱(Raman)和氮气吸附-脱附(BET)等手段对制备的材料进行了表征,结果表明:采用果皮预碳化、活化的方法可以得到N、O、S杂原子原位共掺杂多孔碳;经过氢氧化钾活化后,碳材料的比表面积大幅增加,比表面积最高可达1698.6 m^2/g。在三电极体系下对制备的碳材料超级电容器性能的评价结果表明:在氢氧化钾与猕猴桃果皮质量比1∶3时,电极材料具有最佳的超电性能;在扫描速率为5 m V/s时,材料的比电容为221.1 F/g,同时具有良好的倍率性能和循环稳定性,经过4000次的长循环后,容量保持率为83.2%。

Certain amount of peelsare generated by fresh fruit mill,and these agricultural solid wastes have not yet been reused and recycled efficiently.In this paper,heteroatoms co-doped porous carbons were prepared from fruit peel of Kiwifruit by chemical activation processes with KOH.The structure of prepared carbon materials were examined by scanning electron microscope(SEM),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),Raman spectroscopy(Raman)and nitrogen adsorption-desorption isotherms(BET).The results showed that nitrogen,oxygen,and sulfur in situ co-doped carbon can be prepared by the pre-carbonization and activation processes.An activated carbon with high surface area up to 1698.6 m^2/g was obtained by optimization of the synthesis conditions.The supercapacitor performance of the prepared carbon material was evaluated in a three-electrode system.When the mass ratio of the KOH and the kiwi peel is about 3∶1,the high specific capacitance of 221.1 F/g is obtained at a scan rate of 5 mV/s.Furthermore,the electrode material has good rate performance and excellent cyclingperformance,with 83.2%capacity retention for up to 4000 cycles.