scholarly journals Nanoporous Activated Carbon Derived from Rice Husk for High Performance Supercapacitor

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Huaxing Xu ◽  
Biao Gao ◽  
Hao Cao ◽  
Xueyang Chen ◽  
Ling Yu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Capacitance ◽  
Current Density ◽  
Average Pore Size ◽  
Nanoporous Carbon ◽  
Cycle Life ◽  
Potential Candidate ◽  
Average Pore ◽  
Nanoporous Activated Carbon

Nanoporous activated carbon material was produced from the waste rice husks (RHs) by precarbonizing RHs and activating with KOH. The morphology, structure, and specific surface area were investigated. The nanoporous carbon has the average pore size of 2.2 nm and high specific area of 2523.4 m2 g−1. The specific capacitance of the nanoporous carbon is calculated to be 250 F g−1at the current density of 1 A g−1and remains 80% for 198 F g−1at the current density of 20 A g−1. The nanoporous carbon electrode exhibits long-term cycle life and could keep stable capacitance till 10,000 cycles. The consistently high specific capacitance, rate capacity, and long-term cycle life ability makes it a potential candidate as electrode material for supercapacitor.

scholarly journals Preparation of High-Performance Activated Carbon from Coffee Grounds after Extraction of Bio-Oil

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 257
Author(s):  
Jie Ren ◽  
Nanwei Chen ◽  
Li Wan ◽  
Guojian Li ◽  
Tao Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
High Performance ◽  
Average Pore Size ◽  
Total Pore Volume ◽  
Micropore Volume ◽  
Bet Surface Area ◽  
Average Pore ◽  
Activation Temperature ◽  
Coffee Grounds ◽  
Bio Oil

In this study, a new method for economical utilization of coffee grounds was developed and tested. The resulting materials were characterized by proximate and elemental analyses, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption–desorption at 77 K. The experimental data show bio-oil yields reaching 42.3%. The optimal activated carbon was obtained under vacuum pyrolysis self-activation at an operating temperature of 450 °C, an activation temperature of 600 °C, an activation time of 30 min, and an impregnation ratio with phosphoric acid of 150 wt.%. Under these conditions, the yield of activated carbon reached 27.4% with a BET surface area of 1420 m2·g−1, an average pore size of 2.1 nm, a total pore volume of 0.747 cm3·g−1, and a t-Plot micropore volume of 0.428 cm3·g−1. In addition, the surface of activated carbon looked relatively rough, containing mesopores and micropores with large amounts of corrosion pits.

Sol-Gel Derived Silica Layers for Low-k Dielectrics Applications

2000 ◽  
Vol 612 ◽  
Author(s):  
Sylvie Acosta ◽  
André Ayral ◽  
Christian Guizard ◽  
Charles Lecornec ◽  
Gérard Passemard ◽  
...  
Keyword(s):  
Average Pore Size ◽  
Sol Gel ◽  
Porous Silica ◽  
Thin Layers ◽  
Gaseous Ammonia ◽  
Potential Candidate ◽  
Average Pore ◽  
Synthesis Strategy ◽  
Silica Layers ◽  
Highly Porous

AbstractPorous silica exhibits attractive dielectric properties, which make it a potential candidate for use as insulator into interconnect structures. A new way of preparation of highly porous silica layers by the sol-gel route was investigated and is presented. The synthesis strategy was based on the use of common and low toxicity reagents and on the development of a simple process without gaseous ammonia post-treatment or supercritical drying step. Defect free layers were deposited by spin coating on 200 mm silicon wafers and characterized. Thin layers with a total porosity larger than 70% and an average pore size of 5 nm were produced. The dielectric constant measured under nitrogen flow on these highly porous layers is equal to ∼ 2.5, which can be compared to the value calculated from the measured porosity, ∼ 1.9. This difference is explained by the presence of water adsorbed on the hydrophilic surface of the unmodified silica.

scholarly journals Preparation and Characterization of Nanoporous Activated Carbon Derived from Prawn Shell and Its Application for Removal of Heavy Metal Ions

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 241 ◽  
Author(s):  
Jian Guo ◽  
Yaqin Song ◽  
Xiaoyang Ji ◽  
Lili Ji ◽  
Lu Cai ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Activated Carbon ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Ph Value ◽  
Average Pore Size ◽  
High Specific Surface Area ◽  
Koh Activation ◽  
Average Pore ◽  
Effects Of Ph

The aim of this study was to optimize the adsorption performance of activated carbon (AC), derived from the shell of Penaeus vannamei prawns, on heavy metal ions. Inexpensive, non-toxic, and renewable prawn shells were subjected to carbonization and, subsequently, KOH-activation to produce nanoporous K-Ac. Carbonized prawn shells (CPS) and nanoporous KOH-activated carbon (K-Ac) from prawn shells were prepared and characterized by FTIR, XRD, BET, SEM, and TEM. The results showed that as-produced K-Ac samples were a porous material with microporous and mesoporous structures and had a high specific surface area of 3160 m2/g, average pore size of about 10 nm, and large pore volume of 2.38 m3/g. Furthermore, batches of K-Ac samples were employed for testing the adsorption behavior of Cd2+ in solution. The effects of pH value, initial concentration, and adsorption time on Cd2+ were systematically investigated. Kinetics and isotherm model analysis of the adsorption of Cd2+ on K-Ac showed that experimental data were not only consistent with the Langmuir adsorption isotherm, but also well-described by the quasi-first-order model. Finally, the adsorption behaviors of as-prepared K-Ac were also tested in a ternary mixture of heavy metal ions Cu2+, Cr6+, and Cd2+, and the total adsorption amount of 560 mg/g was obtained.

scholarly journals Removal of nitrate from synthetic aqueous solution and groundwater in a continuous pilot system using chemical activated carbon derived from walnut shell

2016 ◽  
Vol 11 (4) ◽  
pp. 784-795 ◽  
Author(s):  
Abolghasem Alighardashi ◽  
Shooza Shahali
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Average Pore Size ◽  
Fixed Bed ◽  
Walnut Shell ◽  
Maximum Adsorption Capacity ◽  
Average Pore ◽  
Langmuir Adsorption ◽  
Bet Specific Surface Area ◽  
Nitrate Adsorption

Excessive nitrate in the water impose a danger to human health and contribute to eutrophication. The present continuous fixed bed pilot study was carried out using granular activated carbon made from walnut shell for removal of nitrate from aqueous solution and natural groundwater. The carbon was characterized using SEM, FTIR and BET. The BET specific surface area and average pore size before nitrate adsorption were 1434.6 m2g−1 and 2.08 nm, respectively, and after were 633.28 m2g−1 and 2.04 nm, respectively. Optimum removal of nitrate was achieved at a contact time of 2 min, pH of 6.5 and a nitrate concentration of 200 mg/l. The hydraulic loading rate was calculated to be 10 m3/h.m2 and the maximum adsorption capacity using the Langmuir adsorption isotherm model (R2 = 0.99) was 10 mg NO3/g. These experiments were also carried out using groundwater and the removal of nitrate decreased from 68% to 60% because of competition with other cations and anions.

Preparation and Characterization of Single and Mixed Activated Carbons Derived from Coconut Shell and Palm Kernel Shell through Chemical Activation Using Microwave Irradiation System

2017 ◽  
Vol 889 ◽  
pp. 215-220 ◽  
Author(s):  
Siti Anis Mohd Amran ◽  
Khudzir Ismail ◽  
Azil Bahari Alias ◽  
Syed Shatir Asghrar Syed-Hassan ◽  
Ali H. Jawad
Keyword(s):  
Activated Carbon ◽  
Pore Size ◽  
Iodine Number ◽  
Average Pore Size ◽  
Palm Kernel ◽  
Coconut Shell ◽  
Activation Process ◽  
Average Pore ◽  
Palm Kernel Shell ◽  
Percentage Removal

Single and mixed coconut shell (CS) and palm kernel shell (PKS) were successfully converted to activated carbon by using potassium hydroxide (KOH) as activating agent. Mixed activated carbon was produced from coconut shell: palm kernel shell at different KOH concentrations of 30%, 40% and 50%. Activation process was performed in a conventional microwave oven at fixed power and time of 600W and 20 minutes respectively. The results showed that activated carbon produced from single and mixed biomass at 40% concentration of KOH exhibited higher adsorption capacity for iodine number and percentage removal of MB with comparison to 30% and 50% of KOH concentrations. The highest BET surface area of 441.19 m2/g was obtained by CSAc-40. Further both CSAc-40 and PKSAc-40 produced an average pore size diameter of less than 2.0 nm which is in the range of micropore region. On contrary, the mixed CSPKSAc-40 produced an average pore size diameter of 6.0 nm which is in the region of mesopore. All the CSAc-40, PKSAc-40 and mixed CSPKSAc-40 showed similar adsorption trend for iodine number and percentage removal of MB. Interestingly, this finding showed that in the mixed activated carbon some chemical reactions might have occurred during the activation process producing mesoporous instead of microporous as obtained by the single biomass activated carbon.

Preparation of lignite-based activated carbon with high specific capacitance for electrochemical capacitors

2015 ◽  
Vol 08 (04) ◽  
pp. 1550031 ◽  
Author(s):  
Baolin Xing ◽  
Jianliang Cao ◽  
Yan Wang ◽  
Guiyun Yi ◽  
Chuanxiang Zhang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Electron Microscope ◽  
Specific Capacitance ◽  
Current Density ◽  
Electrode Materials ◽  
High Current Density ◽  
Electrochemical Capacitors ◽  
High Specific Capacitance ◽  
High Current ◽  
Charge Discharge

A lignite-based activated carbon (LAC) for electrochemical capacitors (ECs) was prepared from high moisture lignite by KOH activation, and the as-prepared sample was characterized by the N 2-sorption, scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The electrochemical performances of ECs with activated carbon as electrodes in 3 M KOH aqueous solution were evaluated by constant current charge-discharge and cyclic voltammetry. The LAC exhibits a well-developed surface area of 2581 m2/g, a relative wide pore size distribution of 0.5–10 nm. The ECs with LAC as electrode materials presents a high specific capacitance of 392 F/g at a low current density of 50 mA/g, and still remains 315 F/g even at a high current density of 5 A/g. The residual specific capacitance is as high as 92.9% after 2000 cycles. Compared with the commercial activated carbon (Maxsorb: Commercial product, Kansai, Japan), the LAC based electrode materials shows superior capacitive performance in terms of specific capacitance and charge–discharge performance at the high current density.

Effect of petroleum coke expanding by perchloric acid on the performance of the resulted activated carbon

2014 ◽  
Vol 07 (01) ◽  
pp. 1350066 ◽  
Author(s):  
Mei-Gen Deng ◽  
Ren-Qing Wang
Keyword(s):  
Activated Carbon ◽  
Petroleum Coke ◽  
Perchloric Acid ◽  
Average Pore Size ◽  
Interplanar Distance ◽  
Mass Ratio ◽  
Power Performance ◽  
Average Pore ◽  
Scan Rate ◽  
And Performance

Petroleum coke (PC) was expanded by using KMnO 4 as oxidant and HClO 4 as intercalator so as to decrease the amount of KOH needed for the successive activation. Activated carbon (AC) was prepared by activation of the expanded PC (EPC) at KOH /coke mass ratio of 3:1 (denoted as EAC-3). As a comparison, AC was also made by activation of PC at KOH /coke mass ratio of 3:1, 4:1 and 5:1 (denoted as AC-3, AC-4 and AC-5). Influence of expanding modification on the structure and performance of PC and AC was investigated. The results revealed that the expanding treatment increased the interplanar distance of PC microcrystalline from 0.344 to 0.362 nm and decreased the microcrystalline thickness from 2.34 to 1.57 nm. The specific surface area of EAC-3 and AC-5 was 3461 and 3291 m2⋅g-1, respectively. The average pore size of EAC-3 was 2.19 nm, which is 0.11 nm larger than that of AC-5. At a scan rate of 0.5 mV⋅s-1, EAC-3 and AC-5 achieved a specific gravimetric capacitance of 486 and 429 F⋅g-1, respectively. Supercapacitor based on EAC-3 possessed lower resistance and better power performance.

Treatment of Slaughterhouse Wastewater by Integrated Anaerobic/Aerobic Bioreactors Loaded with Immobilized Nanoporous Activated Carbon

2021 ◽  
Vol 116 (9) ◽  
Author(s):  
P. Maharaja ◽  
M. Mahesh ◽  
N. Patchaimurugan ◽  
S. Swarnalatha ◽  
G. Sekaran
Keyword(s):  
Activated Carbon ◽  
High Strength ◽  
Bet Surface Area ◽  
Carbon Oxidation ◽  
Immobilized Cell ◽  
Free Electrons ◽  
Average Pore ◽  
Slaughterhouse Wastewater ◽  
And Cluster Analysis ◽  
Nanoporous Activated Carbon

Slaughterhouse wastewater consists of moderate to high strength complex wastewater comprising about 45% soluble and 55% coarse suspended organics exhibiting high COD and BOD levels. Conventional wastewater treatment methods cannot effectively treat slaughterhouse wastewater. Thus, a four-stage sequential anaerobic/aerobic immobilized bio reactor system comprising a two stage Fluidized Anaerobic immobilized Reactor (FAIR – I and FAIR – II), a Fluidized Immobilized Cell Carbon Oxidation (FICCO) reactor and a Chemo Autotrophic Activated Carbon Oxidation (CAACO) reactor was tested in a slaughterhouse treating wastewater between 3 m3 /day to 17 m3 /day. Nanoporous activated carbon (NPAC) was used for the immobilization of microorganisms in all of the reactors. The NPAC BET surface area was found to be 291 m2/g with the average pore diameter of 28 Å. Spin density (free electrons) in the NPAC, was calculated to be 16 x 1018 spins/g using ESR spectroscopy. The overall NH3-N, TKN, COD and BOD removal efficiency was 64%, 71%, 82% and 85% respectively. Multivariate analysis (PCA and cluster analysis) found that the COD removal by the FICCO and CAACO reactors is more efficient than the FAIR reactors. The treatment was confirmed through UV-visible and UV-fluorescence spectroscopic analysis.

Preparation of Activated Carbon from Blue Coke Powder and its Adsorption Properties of Cr(VI)

2010 ◽  
Vol 156-157 ◽  
pp. 1347-1351 ◽  
Author(s):  
Yu Hong Tian ◽  
Xin Zhe Lan ◽  
Lin Bo Li ◽  
Xiang Yang Chen ◽  
Tang Hua Hu
Keyword(s):  
Activated Carbon ◽  
Average Pore Size ◽  
Total Pore Volume ◽  
Adsorption Properties ◽  
Physical Activation ◽  
Order Kinetic ◽  
Average Pore ◽  
Endothermic Process ◽  
Powder Activated Carbon ◽  
Coke Powder

Activated carbon was prepared from blue coke powder by physical activation. The results show that the specific surface area (BET) is 697.05m2/g, the total pore volume is 0.4569cm3/g and the average pore size is 2.6221nm. The adsorption properties of Cr( ) onto blue coke powder activated carbon are discussed from the kinetics and thermodynamics viewpoints. The pseudo-second-order kinetic model shows the best correlation with experimental data. Langmuir and Freundlich models are used to fit the equilibrium, and it is indicated that Freundlich best fits these data. The adsorption of Cr( ) onto blue coke powder activated carbon is found to be an endothermic process in nature.

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