Nitrogen-containing mesoporous carbons with high capacitive properties derived from a gelatin biomolecule
Nitrogen-containing mesoporous carbons with high capacitive properties derived from a gelatin biomolecule
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DOI：
10.1016/j.carbon.2015.04.025
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发表时间：
2015-09
期刊：
影响因子：
10.9
通讯作者：
A. Olejniczak;M. Leżańska;Aleksandra Pacuła;P. Nowak;J. Włoch;J. Łukaszewicz
中科院分区：
文献类型：
--
作者：
A. Olejniczak;M. Leżańska;Aleksandra Pacuła;P. Nowak;J. Włoch;J. Łukaszewicz
以廉价易得的明胶生物聚合物为碳/氮前驱体，硅胶为硬模板，合成了富氮介孔碳材料。所得材料表现出高达4.38cm3/g的大孔体积、双峰孔隙率（孔以约3和24-28 nm为中心）并且含有高水平的本体和表面氮（高达10重量%和5.8原子%，通过循环伏安法、恒电流充放电循环和电化学阻抗谱研究了炭在6 M KOH和1 M H2SO 4水溶液中的电化学性能。样品在碱性和酸性溶液中分别表现出高达230和335 F/g的高电容。在酸性介质中，高电位扫描速率（100 mV/s）下的电容保持率（75-80%）低于碱性介质中的电容保持率（约94%），表明赝电容在快速充放电过程中的作用不大。结果表明，如果明胶的等电点和胶体二氧化硅溶液的pH值是相似的，那么过度的自缔合和沉淀可能会发生，从而降低所得碳的孔隙率。
Nitrogen-rich mesoporous carbons were synthesized using an inexpensive and readily available gelatin biopolymer as a carbon/nitrogen precursor and colloidal silica as a hard template. The resulting materials exhibited large pore volumes of up to 4.38 cm3/g, bimodal porosity (pores centered at approximately 3 and 24–28 nm) and contained high levels of bulk and surface nitrogen (up to 10 wt% and 5.8 at.%, respectively).The electrochemical properties of the carbons were evaluated in 6 M KOH and 1 M H2SO4aqueous solutions via cyclic voltammetry, galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy. The samples exhibited high capacitances of up to 230 and 335 F/g in alkaline and acidic solutions, respectively. The capacitance retention in the acidic solution at a high potential sweep rate (100 mV/s) was lower (75–80%) than that in the alkaline medium (∼94%), suggesting that pseudocapacitance contributes less effectively in quick charge/discharge operations.The influence of the chemistry of gelatin on its compatibility with colloidal silica is discussed. It is shown that if the values of the isoelectric point of the gelatin and the pH of the colloidal silica solution are similar, then excessive self-association and precipitation may occur, thereby decreasing the porosity of the resulting carbons.