3-D hierarchical porous carbon from oxidized lignin by one-step activation for high-performance supercapacitor.
3-D hierarchical porous carbon from oxidized lignin by one-step activation for high-performance supercapacitor.
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DOI：
10.1016/j.ijbiomac.2021.03.048
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发表时间：
2021-03
影响因子：
8.2
通讯作者：
Xue Wan;Fei Shen;Jinguang Hu;Mei Huang;Li Zhao;Yongmei Zeng;D. Tian;Gang Yang;Yanzong Zhang
中科院分区：
文献类型：
--
作者：
Xue Wan;Fei Shen;Jinguang Hu;Mei Huang;Li Zhao;Yongmei Zeng;D. Tian;Gang Yang;Yanzong Zhang
为了将木质素转化为高价值的碳材料并了解木质素的结构功能，采用KOH一步活化法对木质纤维素PHP预处理（磷酸+过氧化氢）的副产物氧化木质素进行了活化，并对活化后的木质素炭的理化性质和电化学性能进行了研究。结果表明，所得碳显示出三维分级多孔形态，最大比表面积为3094 m2 g − 1，孔体积为1.72 cm 3 g − 1，使用3：1的KOH/木质素比例进行碳化。三电极测定在0.5 A g−1的电流下实现了352.9 F g− 1的比电容，表明该碳具有优异的上级倍率性能。双电极测定在25.0 W kg−1的功率密度下获得了9.5 W h kg − 1的优异能量密度。此外，5000次充放电循环在5A g-1下的保持率达到88.46%，这意味着出色的循环稳定性。氧化木质素分子量低、含氧官能团丰富，是制备高性能超级电容器用活性炭的理想前驱体。总体而言，这项工作为氧化预处理技术产生的木质素副产物的增值提供了一条新的途径，可以进一步促进木质纤维素生物炼制的完整性。
To convert lignin into high-valued carbon materials and understand the lignin structure function, oxidized lignin, a by-product from lignocellulose PHP-pretreatment (phosphoric acid plus hydrogen peroxide), was carbonized by one-step KOH-activation; the physico-chemical characteristics and electrochemical performances of the harvested carbons were also investigated. Results indicated the resultant carbons displayed 3-dimensional hierarchical porous morphology with maximum specific surface area of 3094 m2g−1and pore volume of 1.72 cm3g−1using 3:1 KOH/lignin ratio for carbonization. Three-electrode determination achieved a specific capacitance of 352.9 F g−1at a current of 0.5 A g−1, suggesting a superior rate performance of this carbon. Two-electrode determination obtained an excellent energy density of 9.5 W h kg−1at power density of 25.0 W kg−1. Moreover, 5000 cycles of charge/discharge reached 88.46% retention at 5 A g−1, implying an outstanding cycle stability. Basically, low molecular weight and abundant oxygen-containing functional groups of employed lignin mainly related to the excellent porous morphology and the outstanding electrochemical performances, suggesting the oxidized lignin was an ideal precursor to facilely prepare activated carbon for high-performance supercapacitor. Overall, this work provides a new path to valorize lignin by-product derived from oxidative pretreatment techniques, which can further promote the integrality of lignocellulose biorefinery.