Sattayarut Vichuda, Chanthad Chalathorn, Khemthong Pongtanawat, Kuboon Sanchai, Wanchaem Thanthamrong, Phonyiem Mayuree, Obata Michiko, Fujishige Masatsugu, Takeuchi Kenji, Wongwiriyapan Winadda, Khanchaitit Paisan, Endo Morinobu
College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang Chalongkrung Rd., Ladkrabang Bangkok 10520 Thailand
National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA) Pathum Thani 12120 Thailand.
RSC Adv. 2019 Mar 28;9(18):9878-9886. doi: 10.1039/c9ra01090d.
In this study, nitrogen-enriched activated carbon from silkworm pupae waste (P-AC) was successfully prepared and its electrochemical performances in aqueous and organic electrolytes were investigated. Silkworm pupae waste is beneficial because it is a nitrogen-enriched, inexpensive, and locally available material. The preparation process includes hydrothermal treatment of the silkworm pupae waste at 200 °C, and chemical activation using zinc chloride at activation temperatures of 700, 800 and 900 °C (P700, P800, and P900, respectively). The nitrogen content in the P-ACs was approximately 3.8-6.4 at%, decreasing with activation temperature, while the surface area was approximately 1062-1267 m g, increasing with activation temperature. Compared to a commercial AC, the P-ACs show higher nitrogen content but lower surface area. Furthermore, the P800 exhibited superior specific capacitance (154.6 and 91.6 F g in aqueous and organic electrolytes) compared to a commercial AC despite possessing smaller surface area. The high nitrogen content enhanced the pseudocapacitance and improved the electrical conductivity of the P-ACs. These properties were confirmed by relatively low series and charge transfer resistances, a capacity retention higher than 88% at a current density of 0.5 A g and excellent cycling stability demonstrated by maintaining 97.6% of its capacitance after 3000 cycles. These results demonstrate that silkworm pupae waste is a viable source of nitrogen-enriched AC for application in supercapacitors.
在本研究中，成功制备了以蚕蛹废弃物为原料的富氮活性炭（P-AC），并研究了其在水性和有机电解质中的电化学性能。蚕蛹废弃物是一种有益的材料，因为它富含氮、价格低廉且在当地容易获取。制备过程包括在200℃对蚕蛹废弃物进行水热处理，以及在700、800和900℃（分别为P700、P800和P900）的活化温度下使用氯化锌进行化学活化。P-AC中的氮含量约为3.8 - 6.4原子百分比，随活化温度降低，而表面积约为1062 - 1267 m²/g，随活化温度增加。与商业活性炭相比，P-AC显示出更高的氮含量但更低的表面积。此外，尽管P800的表面积较小，但与商业活性炭相比，它在水性和有机电解质中表现出优异的比电容（分别为154.6和91.6 F/g）。高氮含量增强了P-AC的赝电容并提高了其电导率。这些特性通过相对较低的串联电阻和电荷转移电阻、在0.5 A/g的电流密度下高于88%的容量保持率以及在3000次循环后保持97.6%的电容所证明的优异循环稳定性得到证实。这些结果表明，蚕蛹废弃物是用于超级电容器的富氮活性炭的可行来源。
