scholarly journals SYNTHESIS, CHARACTERIZATION AND ELECTROCHEMICAL PERFORMANCE OF ACTIVATED CARBON SUPPORTED MnO2 FOR ELECTROCHEMICAL CAPACITOR

2018 ◽  
Vol 56 (5) ◽  
Author(s):  
Thuy Thu Luong Thi ◽  
Khu Van Le ◽  
Lien Kim Nguyen Thi
Keyword(s):  
Activated Carbon ◽  
Electrochemical Performance ◽  
Specific Surface ◽  
Surface Area ◽  
Pore Volume ◽  
Manganese Content ◽  
Electrochemical Capacitor ◽  
Reduction Temperature ◽  
Magnetic Stirring ◽  
Ultrasonic Stirring

MnO2 was synthesized by adding activated carbon into KMnO4 solution and stirred in a magnetic or ultrasonic stirrer. The obtained MnAC samples were characterized by means of XRD, TGA, TPR-H2, SEM and BET. All samples are amorphous and have porous structure. MnAC-M prepared by magnetic stirring have higher manganese content, earlier reduction temperature, smoother surface area while MnAC-U prepared by ultrasonic stirring have larger specific surface area and pore volume.

Study of the Porous Structure and High Adsorption Capacity of Biomass-Based Activated Carbon Prepared from Aspen Wood by Ferric Nitrate III Activation

2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Mass Ratio ◽  
Aspen Wood ◽  
Surface Functional Groups ◽  
Wood Sawdust

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.

Optimization of Experimental Conditions for the Preparation of High Specific Surface Area Bamboo-Based Activated Carbon

2015 ◽  
Vol 1090 ◽  
pp. 154-159
Author(s):  
Sheng Zhou Zhang ◽  
Hong Ying Xia ◽  
Li Bo Zhang ◽  
Jin Hui Peng ◽  
Jian Wu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Total Pore Volume ◽  
High Specific Surface Area ◽  
Raw Material ◽  
Experimental Conditions ◽  
Average Pore

Bamboo as the raw material is carbonized to prepare high specific surface area activated carbon by microwave heating under nitrogen atmosphere in our present work. Influences of activation agents on the preparation of activated carbon are studied. The results show that activation agents have a significant influence on the preparation of activated carbon. Under the heating time of 15 min, the adsorption capacity of the activated carbon prepared utilizing KOH as activation agent is the best. When the KOH/C ratio is 4, the iodine number and yield of activated carbon are 2298 mg/g and 39.82%, respectively. The BET specific surface area, total pore volume and average pore diameter of activated carbon are 3441 m2/g, 2.093 ml/g and 2.434 nm, respectively. The micropore volume of 1.304 ml/g is 62.30% of total pore volume, indicating that the activated carbon is microporous activated carbon.

scholarly journals Effect of Mesopore Development on Butane Working Capacity of Biomass-Derived Activated Carbon for Automobile Canister

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 673
Author(s):  
Byeong-Hoon Lee ◽  
Hye-Min Lee ◽  
Dong Chul Chung ◽  
Byung-Joo Kim
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Volume Fraction ◽  
Activated Carbons ◽  
Total Pore Volume ◽  
Working Capacity ◽  
Activation Time

Kenaf-derived activated carbons (AKC) were prepared by H3PO4 activation for automobile canisters. The microstructural properties of AKC were observed using Raman spectra and X-ray diffraction. The textural properties were studied using N2/77 K adsorption isotherms. Butane working capacity was determined according to the ASTM D5228. From the results, the specific surface area and total pore volume of the AKC was determined to be 1260–1810 m2/g and 0.68–2.77 cm3/g, respectively. As the activation time increased, the butane activity and retentivity of the AKC increased, and were observed to be from 32.34 to 58.81% and from 3.55 to 10.12%, respectively. The mesopore ratio of activated carbon increased with increasing activation time and was observed up to 78% at 973 K. This indicates that butane activity and retentivity could be a function not only of the specific surface area or total pore volume, but also of the mesopore volume fraction in the range of 2.8–3.8 nm and 5.5-6.5 nm of adsorbents, respectively. The AKC exhibit enhanced butane working capacity compared to commercial activated carbon with the high performance of butane working capacity due to its pore structure having a high mesopore ratio.

scholarly journals Effect of Ball Milling on the Electrochemical Performance of Activated Carbon with a Very High Specific Surface Area

Batteries ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 22 ◽  
Author(s):  
Takuya Eguchi ◽  
Yugo Kanamoto ◽  
Masahiro Tomioka ◽  
Daisuke Tashima ◽  
Seiji Kumagai
Keyword(s):  
Activated Carbon ◽  
Electrochemical Performance ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Ball Milling ◽  
Surface Area ◽  
Milling Time ◽  
High Specific Surface Area ◽  
Ion Transportation ◽  
Very High

Activated carbon (AC) with a very high specific surface area of >3000 m2 g−1 and a number of course particles (average size: 75 µm) was pulverized by means of planetary ball milling under different conditions to find its greatest performances as the active material of an electric double-layer capacitor (EDLC) using a nonaqueous electrolyte. The variations in textural properties and particle morphology of the AC during the ball milling were investigated. The electrochemical performance (specific capacitance, rate and cyclic stabilities, and Ragone plot, both from gravimetric and volumetric viewpoints) was also evaluated for the ACs milled with different particle size distributions. A trade-off relation between the pulverization and the porosity maintenance of the AC was observed within the limited milling time. However, prolonged milling led to a degeneration of pores within the AC and a saturation of pulverization degree. The appropriate milling time provided the AC a high volumetric specific capacitance, as well as the greatest maintenance of both the gravimetric and volumetric specific capacitance. A high volumetric energy density of 6.6 Wh L−1 was attained at the high-power density of 1 kW L−1, which was a 35% increment compared with the nonmilled AC. The electrode densification (decreased interparticle gap) and the enhanced ion-transportation within the AC pores, which were attributed to the pulverization, were responsible for those excellent performances. It was also shown that excessive milling could degrade the EDLC performances because of the lowered micro- and meso-porosity and the excessive electrode densification to restrict the ion-transportation within the pores.

scholarly journals Pore Structure Regulation and Electrochemical Performance Characterization of Activated Carbon for Supercapacitors

2021 ◽  
Vol 9 ◽  
Author(s):  
Shijie Li ◽  
Tao Xing ◽  
Yilin Wang ◽  
Pengwei Lu ◽  
Weixue Kong ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Activation Time ◽  
Activation Temperature ◽  
Specific Pore Volume ◽  
Impregnation Time

In order to achieve the purpose of regulating the pore structure characteristics of activated carbon by adjusting the experimental parameters, the effects of carbonization temperature, carbonization time, pre-activation temperature, pre-activation time and impregnation time on the pore structure of sargassum-based activated carbon (SAC) are studied by orthogonal experiment. The gravimetric capacitance of SAC and the relationship between the gravimetric capacitance and specific surface area are also studied. The results show that the SACs prepared at all experimental conditions have developed pore structure and huge specific surface area, reaching 3,122 m2/g. The pore size of SAC is almost all within 6 nm, in which the micropores are mainly concentrated in 0.4–0.8 nm, the mesopores are mainly concentrated in 2–4 nm, and the number of micropores is significantly higher than that of mesopores. During the preparation of SAC, the effect of carbonization temperature on the specific surface area and specific pore volume of SAC is very significant. The effect of carbonization time on the specific surface area of SAC is significant, but the effect on specific pore volume can be ignored. The effects of pre-activation temperature, pre-activation time, and impregnation time on specific surface area and specific pore volume of SAC can be ignored. In addition, SACs show good gravimetric capacitance performance as electrode material for supercapacitors, which can significantly increase the capacitance of supercapacitors and thus broaden their applications. The gravimetric capacitance and specific surface area of SACs show a good linear relationship when the activated carbons have similar material properties and pore size distribution.

Optimization Conditions of Modified Activated Carbon and the Adsorption of Phenol

2010 ◽  
Vol 113-116 ◽  
pp. 1716-1721 ◽  
Author(s):  
Chun Sheng Ding ◽  
Fang Ming Ni ◽  
Hui Ye Cai ◽  
Qian Fen Zhu ◽  
Ying Long Zou
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Langmuir Model ◽  
Adsorption Behavior ◽  
Absorption Mechanism ◽  
Modified Activated Carbon ◽  
Freundlich Model

To optimize the conditions of modification and understand the absorption mechanism of activated carbon, the orthogonal test was used to select the best conditions of ammonia-modified activated carbon. The changes of activated carbon’s specific surface area, pore volume and surface acidic oxygen-containing functional groups were determined before and after modification by ammonia, and the equilibrium adsorption model for phenol was also explored. The results show that under the conditions of ammonia concentration of 10%, soaking time of 2h, activation time of 2.5h and activation temperature of 500°C, the best removal rate could be obtained. The specific surface area and pore volume of modified activated carbon were increased, whereas the acidic oxygen-containing groups of its surface were significantly reduced by 57.88% after modification. It means the surface polarity of carbon was decreased, and which was conducive to the adsorption of phenol, since phenol was a weakly polar substance. Both Freundlich and Langmuir model could reflect the adsorption behavior of modified activated carbon for phenol, while the Freundlich model was more properly, but for the unmodified activated carbon, Freundlich model was more suited to describe the adsorption behavior of phenol than Langmuir model.

scholarly journals Pitch-Derived Activated Carbon Fibers for Emission Control of Low-Concentration Hydrocarbon

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1313 ◽  
Author(s):  
Hye-Min Lee ◽  
Byeong-Hoon Lee ◽  
Soo-Jin Park ◽  
Kay-Hyeok An ◽  
Byung-Joo Kim
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Fibers ◽  
Pore Volume ◽  
Volume Fraction ◽  
Structural Characteristics ◽  
Total Pore Volume ◽  
Activated Carbon Fibers

The unburned hydrocarbon (HC) emissions of automobiles are subject to strong regulations because they are known to be converted into fine dust, ozone, and photochemical smog. Pitch-based activated carbon fibers (ACF) prepared by steam activation can be a good solution for HC removal. The structural characteristics of ACF were observed using X-ray diffraction. The pore characteristics were investigated using N2/77K adsorption isotherms. The butane working capacity (BWC) was determined according to ASTM D5228. From the results, the specific surface area and total pore volume of the ACF were determined to be 840–2630 m2/g and 0.33–1.34 cm3/g, respectively. The butane activity and butane retentivity of the ACF increased with increasing activation time and were observed to range between 15.78–57.33% and 4.19–11.47%, respectively. This indicates that n-butane adsorption capacity could be a function not only of the specific surface area or total pore volume but also of the sub-mesopore volume fraction in the range of 2.0–2.5 nm of adsorbents. The ACF exhibit enhanced BWC, and especially adsorption velocity, compared to commercial products (granules and pellets), with lower concentrations of n-butane due to a uniformly well-developed pore structure open directly to the outer surface.

scholarly journals Properties of activated carbon regulated by rapid cooling treatment after pyrolysis

BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 7935-7942
Author(s):  
Bing Wang ◽  
Huiyuan Chen ◽  
Yonggang Li ◽  
Hongyu Si ◽  
Haomin Wei ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Activated Carbons ◽  
Raw Materials ◽  
Average Pore Size ◽  
Process Conditions ◽  
Rapid Cooling

Effects of rapid cooling following pyrolysis were studied relative to the properties of activated carbon using different biomass as the raw materials. Coconut shell-based activated carbon (CSAC), bamboo-based activated carbon (BAC), and straw-based activated carbon (WSAC) were activated via high temperature and subsequently rapidly cooled to below minus 150 °C. The results showed that rapid cooling effectively increased the specific surface area, pore volume, and yield of activated carbons. Compared to natural cooling, rapid cooling increased the specific surface area of CSAC from 1076 m2/g to 1484 m2/g, increased the pore volume from 1.46 mL/g to 1.57 mL/g, decreased the average pore size from 2.25 nm to 2.13 nm, and increased the yield from 27.1% to 31.5%. The variation of the properties of activated carbon after rapid cooling using different raw materials and process conditions were studied using orthogonal experiments.

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