Potassium Humate-Derived Nitrogen-Doped Activated Carbons with Narrow Micropore Size Distribution for High-Performance Supercapacitors

NANO ◽  
2017 ◽  
Vol 12 (04) ◽  
pp. 1750040
Author(s):  
Lingli Xie ◽  
Litao Kang ◽  
Yae Li ◽  
Mangwei Cui ◽  
Bo Chang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Size Distribution ◽  
High Performance ◽  
Activated Carbons ◽  
Potassium Acetate ◽  
High Specific Surface Area ◽  
Low Grade ◽  
Potassium Humate ◽  
Surface Areas ◽  
Activating Agent

Micro-porous activated carbons (ACs) with a narrow pore size distribution of 0.4–0.6[Formula: see text]nm and high specific surface areas (1160–1315[Formula: see text]m2[Formula: see text][Formula: see text] g[Formula: see text] are prepared from environment-friendly, low-grade potassium humate (HA-K, carbon resource) and mild activating agent potassium acetate (CH3COOK). Microstructure characterizations indicate that the introduction of activating agent CH3COOK is a key step to achieve high specific surface area and carbonization degree. These ACs contain small amount of oxygen and nitrogen, and show obvious pseudo-capacitance besides double layer capacitance. As a result, the optimized ACs achieve high specific capacitances of 311[Formula: see text]F[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] and 317[Formula: see text]F[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] at 0.1[Formula: see text]A[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] in 2[Formula: see text]M KOH and 1[Formula: see text]M H2SO4 aqueous electrolytes, respectively. This sample also shows a good charge-discharge cycling stability within 10 000 cycles.

Preparation and Characterization of Microporous Hemp Stem-Based Activated Carbons

2013 ◽  
Vol 821-822 ◽  
pp. 1307-1312
Author(s):  
Xin Yu Cui ◽  
Jian Min Gao ◽  
Xin Min Hao ◽  
Jin Ju Sun ◽  
Tian Ma ◽  
...  
Keyword(s):  
Specific Surface ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Micropore Surface Area ◽  
Activating Agent ◽  
Micropore Size ◽  
Area And Volume

Activated carbons are prepared from hemp stem with KOH as activating agent under different ratio of KOH to carbon conditions. The BET(Brunauer Emmett and Teller) specific surface area of the hemp stem-based activated carbons first increases and then decreases with the increasing ratio of KOH to carbon. The specific surface area, micropore surface area and volume of the activated carbons reach a maximum of 1589.27m2/g 1420.52m2/g, 89% of the total area, 0.751m3/g at the ratio of 4.5:1. The micropore size distribution shows the activated carbons contain a large number of ultramicropore and supermicropore.

scholarly journals Role of pulping process as synergistic treatment on performance of agro-based activated carbons

2019 ◽  
Vol 6 (7) ◽  
pp. 190579 ◽  
Author(s):  
Altaf H. Basta ◽  
Vivian F. Lotfy ◽  
Philippe Trens
Keyword(s):  
Specific Surface ◽  
High Performance ◽  
Activated Carbons ◽  
Sorption Properties ◽  
Surface Areas ◽  
Pseudo Second Order ◽  
Specific Surface Areas ◽  
The One ◽  
Reported Data ◽  
The Impact

To recommend the beneficial effect of the pulping process on enhancing agro-wastes as precursors for the production of high-performance activated carbons (ACs), different pulping methods (alkali, sulfite and neutral sulfite) were applied on two available Egyptian agriculture by-products (rice straw and sugar cane bagasse), using the one-step pyrolysis method and H 3 PO 4 activating agent. The adsorption performance of the different prepared ACs was evaluated in terms of Iodine Numbers and their sorption properties for removing the methylene blue (MB) from aqueous solutions. The corresponding sorption processes were also analysed using Lagergren first order, pseudo-second order and intraparticle diffusion models. Data revealed that the applied pulping conditions were effective for removing the non-cellulosic constituents of agro-residues. This was demonstrated by the hydrogen/carbon and oxygen/carbon ratios, thermal stability and IR-measurements of the final pulps. These data were effective on the particular sorption properties of RS and SCB-based ACs. Interestingly, the pulping process is a profound modification of the SCB-based fibres, on which it induced a clear increase of the specific surface areas of the corresponding ACs even though they had an impact on the sorption of MB and iodine. These values are superior to the reported data on agro-based ACs with H 3 PO 4 activators. Pulping processes therefore play a dual role in the sorption properties of ACs. The first important role is the impact on the specific surface areas and the second impact is a profound modification of the surface chemistry of the ACs. Therefore, SCB-based ACs can be seen as an economical breakthrough product, and an alternative to the high-cost commercial ACs for the purification of industrial wastewaters.

Hierarchically porous activated carbons prepared via a dissipative process: high-capacity cathode for Li ion capacitors

Nanoscale ◽  
2021 ◽  
Author(s):  
Qi Cao ◽  
Guoqing Ning ◽  
Fan Yang ◽  
Ye Wang ◽  
Bofeng Li ◽  
...  
Keyword(s):  
Energy Storage ◽  
Specific Surface ◽  
High Performance ◽  
Activated Carbons ◽  
High Capacity ◽  
High Specific Surface Area ◽  
Dissipative Process ◽  
Capacitive Energy Storage ◽  
Hierarchically Porous ◽  
Li Ion

Activated carbons with high specific surface area (SSA) and well-modulated pore structure are highly desirable for achieving high-performance capacitive energy storage. Herein, hierarchically porous activated carbons (PACs) are synthesized by...

KCl-assisted activation: Moringa oleifera branch-derived porous carbon for high performance supercapacitor

2021 ◽  
Vol 45 (12) ◽  
pp. 5712-5719
Author(s):  
Yongxiang Zhang ◽  
Peifeng Yu ◽  
Mingtao Zheng ◽  
Yong Xiao ◽  
Hang Hu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
High Performance ◽  
Moringa Oleifera ◽  
High Specific Surface Area ◽  
Porous Carbons

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.

scholarly journals The Effects of Methane Storage Capacity Using Upgraded Activated Carbon by KOH

2018 ◽  
Vol 8 (9) ◽  
pp. 1596 ◽  
Author(s):  
Jung Park ◽  
Gi Lee ◽  
Sang Hwang ◽  
Ji Kim ◽  
Bum Hong ◽  
...  
Keyword(s):  
Surface Area ◽  
Storage Capacity ◽  
Activated Carbons ◽  
Chemical Activation ◽  
High Surface ◽  
Heat Of Adsorption ◽  
Low Grade ◽  
Surface Areas ◽  
Ch4 Adsorption ◽  
Ch4 Storage

In this study, a feasible experiment on adsorbed natural gas (ANG) was performed using activated carbons (ACs) with high surface areas. Upgraded ACs were prepared using chemical activation with potassium hydroxide, and were then applied as adsorbents for methane (CH4) storage. This study had three principal objectives: (i) upgrade ACs with high surface areas; (ii) evaluate the factors regulating CH4 adsorption capacity; and (iii) assess discharge conditions for the delivery of CH4. The results showed that upgraded ACs with surface areas of 3052 m2/g had the highest CH4 storage capacity (0.32 g-CH4/g-ACs at 3.5 MPa), which was over two times higher than the surface area and storage capacity of low-grade ACs (surface area = 1152 m2/g, 0.10 g-CH4/g-ACs). Among the factors such as surface area, packing density, and heat of adsorption in the ANG system, the heat of adsorption played an important role in controlling CH4 adsorption. The released heat also affected the CH4 storage and enhanced available applications. During the discharge of gas from the ANG system, the residual amount of CH4 increased as the temperature decreased. The amount of delivered gas was confirmed using different evacuation flow rates at 0.4 MPa, and the highest efficiency of delivery was 98% at 0.1 L/min. The results of this research strongly suggested that the heat of adsorption should be controlled by both recharging and discharging processes to prevent rapid temperature change in the adsorbent bed.

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