Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria, 0028, South Africa.
Laboratoire de Photonique Quantique Energie, et Nano-Fabrication, Faculté des Sciences et Techniques Université Cheikh Anta Diop de Dakar (UCAD), B.P. 5005, Dakar-Fann Dakar, Sénégal.
Sci Rep. 2019 Sep 20;9(1):13673. doi: 10.1038/s41598-019-50189-x.
In this study, the synthesis of porous activated carbon nanostructures from peanut (Arachis hypogea) shell waste (PSW) was described using different porosity enhancing agents (PEA) at various mass concentrations via a two-step process. The textural properties obtained were depicted with relatively high specific surface area values of 1457 m g, 1625 m g and 2547 m g for KHCO KCO and KOH respectively at a mass concentration of 1 to 4 which were complemented by the presence of a blend of micropores, mesopores and macropores. The structural analyses confirmed the successful transformation of the carbon-containing waste into an amorphous and disordered carbonaceous material. The electrochemical performance of the material electrodes was tested in a 2.5 M KNO aqueous electrolyte depicted its ability to operate reversibly in both negative and positive potential ranges of 0.90 V. The activated carbon obtained from the carbonized CPSW:PEA with a mass ratio of 1:4 yielded the best electrode performance for all featured PEAs. The porous carbons obtained using KOH activation displayed a higher specific capacitance and the lower equivalent series resistance as compared to others. The remarkable performance further corroborated the findings linked to the textural and structural properties of the material. The assembled device operated in a neutral electrolyte (2.5 M KNO) at a cell potential of 1.80 V, yielded a ca. 224.3 F g specific capacitance at a specific current of 1 A g with a corresponding specific energy of 25.2 Wh kg and 0.9 kW kg of specific power. This device energy was retained at 17.7 Wh kg when the specific current was quadrupled signifying an excellent supercapacitive retention with a corresponding specific power of 3.6 kW kg. These results suggested that peanut shell waste derived activated carbons are promising candidates for high-performance supercapacitors.
在这项研究中，描述了使用不同浓度的不同孔隙增强剂（PEA）通过两步法从花生（Arachis hypogea）壳废物（PSW）合成多孔活性炭纳米结构。通过在 1 到 4 的质量浓度下分别使用 KHCO3、K2CO3 和 KOH 作为 PEA，获得了具有相对较高比表面积值（分别为 1457 m2/g、1625 m2/g 和 2547 m2/g）的纹理特性，并且存在微孔、中孔和大孔的混合物。结构分析证实了成功地将含碳废物转化为无定形和无序的碳质材料。在 2.5 M KNO3 水性电解质中测试了材料电极的电化学性能，表明其能够在 0.90 V 的负电位和正电位范围内可逆地工作。在所有特征 PEA 中，由 CPSW:PEA（质量比为 1:4）碳化得到的活性炭表现出最佳的电极性能。与其他 PEA 相比，使用 KOH 活化得到的多孔碳显示出更高的比电容和更低的等效串联电阻。显著的性能进一步证实了与材料的结构和结构特性相关的发现。在中性电解质（2.5 M KNO3）中，在 1.80 V 的电池电位下，组装的器件在 1 A/g 的特定电流下表现出约 224.3 F/g 的比电容，相应的比能量为 25.2 Wh/kg 和 0.9 kW/kg 的比功率。当特定电流增加四倍时，该器件的能量保持在 17.7 Wh/kg，这表明具有出色的超级电容保持能力，相应的比功率为 3.6 kW/kg。这些结果表明，从花生壳废物中提取的活性炭是高性能超级电容器的有前途的候选材料。
