scholarly journals Preparation and Electrical Properties of Polyacrylonitrile Based Porous Carbon by Different Activation Methods

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3499
Author(s):  
Xiaoqiang Wang ◽  
Yifan Tan ◽  
Meijiao Sun ◽  
Binbin Yu ◽  
Junhe Yang ◽  
...  

Polyacrylonitrile (PAN)-based porous carbon was prepared by different methods of activation with PAN polymer microsphere as precursor. The morphology, structure and electrical properties for supercapacitor of the porous carbon were investigated. It was found that the morphology of PAN nanospheres tended to be destroyed in the process of one-step activation (activation and carbonization were carried out simultaneously, and could only be retained when the amount of activating agent KOH was small). While the spherical morphology could be well reserved during the two-step activation method (carbonization and activation sequentially). The specific surface area and pore volume increased first and then decreased, with the increase in activation holding time for both one-step and two-step activation methods. The specific surface area reached the maximum value with 2430 m2 g−1 for the one-step activation method and 2830 m2 g−1 for the two-step activation method. Additionally, their mass-specific capacitances were 178.8 F g−1 and 160.2 F g−1, respectively, under the current density of 1 A g−1. After 2000 cycles, the specific capacitance retentions were 92.9% and 91.3%.

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Shijie Li ◽  
Heshuai Cui ◽  
Qianli Ma ◽  
Xing’e Liu ◽  
Youhong Wang ◽  
...  

AbstractThe sol–gel method was used to prepare rattan-based silicon carbide (R–SiC) composite ceramics under different pyrolysis parameters through adjustment of the temperature and retention time of the one-step pyrolysis process. The crystalline phases, microscopic morphology, element distribution and specific surface area of the silicon carbide (SiC) were characterized by X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), X-ray fluorescence spectrometer (XRF), field-emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and N2 physisorption. The results showed that the R–SiC prepared at different pyrolysis parameters was able to retain the porous structure of pristine rattan stem. The R–SiC prepared at 1500 ℃ for 120 min possessed the lowest density (0.25 g/cm3), the largest specific surface area (43.38 m2/g) and the highest SiC yield (44.24%). The SiC whisker was the major SiC morphology on the cross section of the R–SiC. Furthermore, the pyrolysis parameters were optimized with the SiC preparation process reaction mechanism, and material transformation methods were also discussed. This one-step pyrolysis process simplified the preparation of biogenic SiC ceramics and thus provided a potential route for the value-added utilization of rattan.


2021 ◽  
Vol 45 (12) ◽  
pp. 5712-5719
Author(s):  
Yongxiang Zhang ◽  
Peifeng Yu ◽  
Mingtao Zheng ◽  
Yong Xiao ◽  
Hang Hu ◽  
...  

Porous carbons with a high specific surface area (2314–3470 m2 g−1) are prepared via a novel KCl-assisted activation strategy for high-performance supercapacitor.


2010 ◽  
Vol 660-661 ◽  
pp. 959-964
Author(s):  
Alexander Rodrigo Arakaki ◽  
Walter Kenji Yoshito ◽  
Valter Ussui ◽  
Dolores Ribeiro Ricci Lazar

One of the main applications of ceria-based (CeO2) ceramics is the manufacturing of Intermediate Temperature Solid Oxide Fuel Cells electrolytes. In order to improve ionic conductivity and densification of these materials various powder synthesis routes have been studied. In this work powders with composition Ce0.8(SmGd)0.2O1.9 have been synthesized by coprecipitation and hydrothermal treatment. A concentrate of rare earths containing 90wt% of CeO2 and other containing 51% of Sm2O3 and 30% of Gd2O3, both prepared from monazite processing, were used as precursor materials. The powders were characterized by X-ray diffraction, scanning and transmission electron microscopy, agglomerate size distribution by laser scattering and specific surface area by gas adsorption. Ceramic sinterability was evaluated by dilatometry and density measurements by Archimedes method. High specific surface area powders (~100m2/g) and cubic fluorite structure were obtained after hydrothermal treatment around 200°C. Ceramic densification was improved when compared to the one prepared from powders calcined at 800°C.


Author(s):  
Yaqi Yang ◽  
Ziqiang Shao ◽  
Feijun Wang

Abstract Due to the low specific capacitance and small specific surface area of conventional carbon materials used as electrode materials for double-layer capacitors, the search for more ideal materials and ingenious preparation methods remains a major challenge. In this study, fractional porous carbon nanosheets were prepared by co-doping Fe and N with chitosan as nitrogen source. The advantage of this method is that the carbon nanosheets can have a large number of pore structures and produce a large specific surface area. The presence of Fe catalyzes the graphitization of carbon in the carbon layer during carbonization process, and further increases the specific surface area of the electrode material. This structure provides an efficient ion and electron transport pathway, which enables more active sites to participate in the REDOX reaction, thus significantly enhancing the electrochemical performance of SCs. The specific surface area of CS-800 is up to 1587 m2 g−1. When the current density is 0.5 A g−1, the specific capacitance of CS-800 reaches 308.84 F g−1, and remains 84.61 % of the initial value after 10,000 cycles. The Coulomb efficiency of CS-800 is almost 100 % after a long cycle, which indicates that CS-800 has more ideal double-layer capacitance and pseudo capacitance.


RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16575-16581 ◽  
Author(s):  
Mingbo Wu ◽  
Peng Li ◽  
Yang Li ◽  
Jun Liu ◽  
Yang Wang

Porous carbons were prepared from enteromorpha with ZnCl2 as active reagent. The prepared porous carbon with a specific surface area of 1651 m2 g−1 exhibited a specific capacitance of 206 F g−1 and capacity retention of 93% even after 5000 cycles.


2020 ◽  
Vol 860 ◽  
pp. 173-177
Author(s):  
Otong Nurhilal ◽  
Renaldy Sharin Lesmana ◽  
Karina Ramadayanti ◽  
Sholihatul Habibah ◽  
Sahrul Hidayat ◽  
...  

Water Hyacinth (WH) is a plant that can absorb various pollutants in water. However, this plant is categorized as an invasive plant that can become a weed in the waters. To improve the functionality of WH, processing of WH is needed to be used for various applications. One of modifications of WH is as porous carbon for battery cathode composite. In this paper, we reported a synthesis of a porous carbon from WH. WH is processed into carbon by carbonization at various temperatures of 400, 500 and 600 °C with various activators of KOH, H3PO4 and ZnCl2 to obtain high quality porous carbon which has high electrical conductivity, large specific surface area and large porous volume. All synthesized carbons were characterized by proximate analysis measurements, scanning electron microscopy (SEM), and N2 adsorption-desorption measurements. The highest carbon fixed content of 37.79% is obtained from charcoal with a carbonization temperature of 400 °C. The largest specific surface area of 264.77 m2/g was obtained from activated carbon with H3PO4 as activator. The values of pore volume and pore radius were 0.186 cm3/g and 1.56 nm, respectively.


2014 ◽  
Vol 116 ◽  
pp. 185-187 ◽  
Author(s):  
Yong Xiao ◽  
Haibin Chen ◽  
Mingtao Zheng ◽  
Hanwu Dong ◽  
Bingfu Lei ◽  
...  

RSC Advances ◽  
2017 ◽  
Vol 7 (32) ◽  
pp. 19934-19939 ◽  
Author(s):  
Yuhang Zhao ◽  
Ping Liu ◽  
Xiaodong Zhuang ◽  
Dongqing Wu ◽  
Fan Zhang ◽  
...  

A hierarchical porous polymeric network (HPPN) with ultrahigh specific surface area up to 2870 m2 g−1 was synthesized via a one-step ionothermal synthesis method without using templates.


RSC Advances ◽  
2019 ◽  
Vol 9 (58) ◽  
pp. 33872-33882
Author(s):  
Genxing Zhu ◽  
Qi Liu ◽  
Fengyi Cao ◽  
Qi Qin ◽  
Mingli Jiao

Silkworm cocoon derived N, O-HPC (SBET = 2270.19 m2 g−1) was synthesized, and demonstrated exceptionally high uptake of MB (2104.29 mg g−1).


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