Shrestha Lok Kumar, Shrestha Rekha Goswami, Maji Subrata, Pokharel Bhadra P, Rajbhandari Rinita, Shrestha Ram Lal, Pradhananga Raja Ram, Hill Jonathan P, Ariga Katsuhiko
International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044, Japan.
Materials Science and Engineering Program, Pulchowk Campus, Institute of Engineering (IOE), Tribhuvan University (TU), Lalitpur, Kathmandu 44700, Nepal.
Nanomaterials (Basel). 2020 Apr 11;10(4):728. doi: 10.3390/nano10040728.
Nanoporous activated carbon materials derived from agro-wastes could be suitable low-cost electrode materials for high-rate performance electrochemical supercapacitors. Here we report high surface area nanoporous carbon materials derived from Lapsi seed agro-waste prepared by zinc chloride (ZnCl) activation at 700 °C. Powder X-ray diffraction (pXRD) and Raman scattering confirmed the amorphous structure of the resulting carboniferous materials, which also incorporate oxygen-containing functional groups as confirmed by Fourier transform infrared (FTIR) spectroscopy. Scanning and transmission electron microscopy (SEM and TEM) analyses revealed the granular, nanoporous structures of the materials. High-resolution TEM (HR-TEM) confirmed a graphitic carbon structure containing interconnected mesopores. Surface areas and pore volumes of the materials were found, respectively, in the ranges from 931 to 2272 m g and 0.998 to 2.845 cm g, and are thus superior to commercially available activated carbons. High surface areas, large pore volumes and interconnected mesopore structures of these Lapsi seed-derived nanoporous carbon materials lead to their excellent electrochemical supercapacitance performance in aqueous electrolyte (1 M HSO) with a maximum specific capacitance of 284 F g at a current density of 1 A g. Furthermore, the electrodes showed high-rate capability sustaining 67.7% capacity retention even at high current density of 20 A g with excellent cycle stability achieving 99% capacitance retention even after 10,000 charge-discharge cycles demonstrating the potential of Lapsi seed derived nanoporous carbons as suitable electrode materials in high-performance supercapacitor devices.
源自农业废弃物的纳米多孔活性炭材料可能是适用于高倍率性能电化学超级电容器的低成本电极材料。在此，我们报告了通过在700°C下用氯化锌（ZnCl）活化由拉普西籽农业废弃物制备的高比表面积纳米多孔碳材料。粉末X射线衍射（pXRD）和拉曼散射证实了所得含碳材料的非晶结构，傅里叶变换红外（FTIR）光谱也证实了其含有含氧官能团。扫描电子显微镜和透射电子显微镜（SEM和TEM）分析揭示了材料的颗粒状纳米多孔结构。高分辨率TEM（HR-TEM）证实了含有相互连接的中孔的石墨碳结构。发现材料的比表面积和孔体积分别在931至2272 m²/g和0.998至2.845 cm³/g范围内，因此优于市售活性炭。这些源自拉普西籽的纳米多孔碳材料的高比表面积、大孔体积和相互连接的中孔结构使其在水性电解质（1 M H₂SO₄）中具有优异的电化学超级电容性能，在1 A/g的电流密度下最大比电容为284 F/g。此外，电极显示出高倍率性能，即使在20 A/g的高电流密度下仍保持67.7%的容量保持率，并且具有出色的循环稳定性，即使在10000次充放电循环后仍实现99%的电容保持率，这证明了源自拉普西籽的纳米多孔碳作为高性能超级电容器器件中合适电极材料的潜力。
