Characterization of Modified Multiwalled Carbon Nanotubes

2014 ◽  
Vol 925 ◽  
pp. 369-373
Author(s):  
Rahmam Syuhaidah ◽  
Norani Muti Mohamed ◽  
Suriati Sufian
Keyword(s):  
Sulfuric Acid ◽  
Functional Group ◽  
High Surface ◽  
High Surface Area ◽  
High Porosity ◽  
Multiwalled Carbon ◽  
Direct Functionalization ◽  
Amine Functional Group

Unique characteristics of MWCNT such as high porosity and high surface area make MWCNT as potential material to be explored in-depth through research. The role of MWCNT as CO2 adsorbent will be more efficient after modification with 3-Aminopropyl triethoxysilane (APTS) in order to obtain amine functional group. However, direct functionalization is not permissible due to the hydrophobic problem faced by pristine MWCNT. This complication can be resolved by liquid oxidation treatment using different types of oxidants such as nitric acid (HNO3), sulfuric acid (H2SO4), and mixture of nitric and sulfuric acid (HNO3/H2SO4). The characteristics of pristine MWCNT and modified MWCNT were investigated by analyzing the samples using scanning electron microscopy and energy dispersive X-ray spectroscopy (FESEM-EDXs), fourier transform infra-red (FTIR), and Raman spectroscopy technique. Higher degree of functionalization implies higher attachment of amine functional group for higher CO2 adsorption. Here, MWCNT sample treated with HNO3/H2SO4 and APTS recorded the highest degree of functionalization.

Synthesis and Characterization of Supercapacitor Electrode from Fiber of Borassus flabelifer L by Activation Method

2019 ◽  
Vol 966 ◽  
pp. 444-450 ◽  
Author(s):  
Fandi Angga Prasetya ◽  
Ufafa Anggarini ◽  
Yudha Zakaria ◽  
Rosa Dwi Sasqia Putri
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Raw Material ◽  
High Porosity ◽  
Supercapacitor Electrode ◽  
Nitrogen Gas ◽  
Reduced Graphene ◽  
Higher Temperature ◽  
Constant Heating

Supercapacitor require electrode which has high surface area so that it able to store large amounts of charge. In this study, electrode was synthesized from carbon of Borassus Flabellifer L fiber which was carried out through activation and carbonization processes. Raw material was calcined at 400°C for 4 hours followed by activation with NaOH 1 M. The carbonization was then conducted in Nitrogen gas flowing by temperature variations; 650°C, 750°C, and 850°C with a constant heating rate of 20 °C/min. Based on XRD data, it was shown that the material has formed Reduced graphene Oxide (RGO) which has main peaks at (2θ) 240 and 440 with higher purity in higher temperature. SEM results clarified more pores formation at higher temperature which is mesoporous. Cyclic Voltammetry (CV) test was done to determine the capacitance value. By RGO forming with high porosity, it is suitable for supercapacitor electrode application and CV test has examined that heating of Borassus Flabelifer L fiber at 850°C with 5 mV/s scan rate has the highest specific capacitance by 8.25 F/gram with Energy density is 4.125 watt/gram.

Preparation and characterization of high surface area, high porosity carbon monoliths from pyrolyzed bovine bone and their performance as supercapacitor electrodes

Carbon ◽  
2013 ◽  
Vol 55 ◽  
pp. 291-298 ◽  
Author(s):  
Paul A. Goodman ◽  
H. Li ◽  
Y. Gao ◽  
Y.F. Lu ◽  
J.D. Stenger-Smith ◽  
...  
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Bovine Bone ◽  
High Porosity

scholarly journals Single and Dual Metal Oxides as Promising Supports for Carbon Monoxide Removal from an Actual Syngas: The Crucial Role of Support on the Selectivity of the Au–Cu System

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 852 ◽  
Author(s):  
Bernay Cifuentes ◽  
Felipe Bustamante ◽  
Martha Cobo
Keyword(s):  
Metal Oxides ◽  
High Surface ◽  
High Surface Area ◽  
Carbon Deposits ◽  
Promising Strategy ◽  
Cu Catalysts ◽  
Dual Metal ◽  
Effect Of The Support ◽  
Lower Capacity

A catalytic screening was performed to determine the effect of the support on the performance of an Au–Cu based system for the removal of CO from an actual syngas. First, a syngas was obtained from reforming of ethanol. Then, the reformer outlet was connected to a second reactor, where Au–Cu catalysts supported on several single and dual metal oxides (i.e., CeO2, SiO2, ZrO2, Al2O3, La2O3, Fe2O3, CeO2-SiO2, CeO2-ZrO2, and CeO2-Al2O3) were evaluated. AuCu/CeO2 was the most active catalyst due to an elevated oxygen mobility over the surface, promoting CO2 formation from adsorption of C–O* and OH− intermediates on Au0 and CuO species. However, its lower capacity to release the surface oxygen contributes to the generation of stable carbon deposits, which lead to its rapid deactivation. On the other hand, AuCu/CeO2-SiO2 was more stable due to its high surface area and lower formation of formate and carbonate intermediates, mitigating carbon deposits. Therefore, use of dual supports could be a promising strategy to overcome the low stability of AuCu/CeO2. The results of this research are a contribution to integrated production and purification of H2 in a compact system.

scholarly journals Highly Porous Carbon Materials from Biomass by Chemical and Carbonization Method: A Comparison Study

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Wan Nor Roslam Wan Isahak ◽  
Mohamed Wahab Mahamed Hisham ◽  
Mohd Ambar Yarmo
Keyword(s):  
Sulfuric Acid ◽  
Thermal Behavior ◽  
Surface Area ◽  
Porous Carbon ◽  
High Surface ◽  
High Surface Area ◽  
Empty Fruit Bunches ◽  
Heating Treatment ◽  
Concentrated Sulfuric Acid ◽  
Highly Porous

Porous carbon obtained by dehydrating agent, concentrated sulfuric acid (H2SO4), from biomass containing high cellulose (filter paper (FP), bamboo waste, and empty fruit bunches (EFB)) shows very high surface area and better thermal behavior. At room temperature (without heating), treatment of H2SO4removed all the water molecules in the biomass and left the porous carbon without emitting any gaseous byproducts. Brunauer-Emmett-Teller (BET) surface analysis has shown that bamboo-based carbon has good properties with higher surface area (507.8 m2/g), micropore area (393.3 m2/g), and better thermal behavior (compared to FP and EFB) without any activation or treatment process. By acid treatment of biomass, it was shown that higher carbon composition obtained from FP (85.30%), bamboo (77.72%), and EFB (76.55%) is compared to carbon from carbonization process. Under optimal sulfuric acid (20 wt.%) uses, high carbon yield has been achieved for FP (47.85 wt.%), bamboo (62.4 wt.%), and EFB (55.4 wt.%).

Highly stable metal-organic framework UiO-66-NH2 for high-performance triboelectric nanogenerators

2021 ◽  
Author(s):  
Yong-Mei Wang ◽  
Xinxin Zhang ◽  
Dingyi Yang ◽  
Liting Wu ◽  
Jiaojiao Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Metal Organic Framework ◽  
High Surface ◽  
High Surface Area ◽  
Triboelectric Nanogenerator ◽  
High Porosity ◽  
Chemically Modified ◽  
Metal Organic ◽  
Triboelectric Nanogenerators ◽  
Organic Framework

Abstract The high porosity, controllable size, high surface area, and chemical versatility of a metal-organic framework (MOF) enable it a good material for a triboelectric nanogenerator (TENG), and some MOFs have been incorporated in the fabrication of TENGs. However, the understanding of effects of MOFs on the energy conversion of a TENG is still lacking, which inhibits the improvement of the performance of MOF-based TENGs. Here, UiO-66-NH2 MOFs were found to significantly increase the power of a TENG and the mechanism was carefully examined. The electron-withdrawing ability of Zr-based UiO-66-family MOFs was enhanced by designing the amino functionalized 1,4-terephthalic acid (1,4-BDC) as ligand. The chemically modified UiO-66-NH2 was found to increase the surface roughness and surface potential of a composite film with MOFs embedded in polydimethylsiloxane (PDMS) matrix. Thus the total charges due to the contact electrification increased significantly. The composite-based TENG was found to be very durable and its output voltage and current were 4 times and 60 times higher than that of a PDMS-based TENG. This work revealed an effective strategy to design MOFs with excellent electron-withdrawing abilities for high-performance TENGs.

Biological weathering in soil: the role of symbiotic root-associated fungi biosensing minerals and directing photosynthate-energy into grain-scale mineral weathering

2008 ◽  
Vol 72 (1) ◽  
pp. 85-89 ◽  
Author(s):  
J. R. Leake ◽  
A. L. Duran ◽  
K. E. Hardy ◽  
I. Johnson ◽  
D. J. Beerling ◽  
...  
Keyword(s):  
Carbon Allocation ◽  
High Surface ◽  
Turgor Pressure ◽  
High Surface Area ◽  
Volume Ratio ◽  
Mineral Weathering ◽  
Mycorrhizal Associations ◽  
P Content ◽  
Biological Weathering

AbstractBiological weathering is a function of biotic energy expenditure. Growth and metabolism of organisms generates acids and chelators, selectively absorbs nutrient ions, and applies turgor pressure and other physical forces which, in concert, chemically and physically alter minerals. In unsaturated soil environments, plant roots normally form symbiotic mycorrhizal associations with fungi. The plants provide photosynthate-carbohydrate-energy to the fungi in return for nutrients absorbed from the soil and released from minerals. In ectomycorrhiza, one of the two major types of mycorrhiza of trees, roots are sheathed in fungus, and 15—30% of the net photosynthate of the plants passes through these fungi into the soil and virtually all of the water and nutrients taken up by the plants are supplied through the fungi. Here we show that ectomycorrhizal fungi actively forage for minerals and act as biosensors that discriminate between different grain sizes (53—90 μm, 500—1000 μm) and different minerals (apatite, biotite, quartz) to favour grains with a high surface-area to volume ratio and minerals with the highest P content. Growth and carbon allocation of the fungi is preferentially directed to intensively interact with these selected minerals to maximize resource foraging.

scholarly journals USE OF MONTMORILLONITE CLAY FOR ADSORPTION MALACHITE GREEN DYE

2019 ◽  
Vol 16 (32) ◽  
pp. 279-286
Author(s):  
Marcos Antônio KLUNK ◽  
Zeban SHAH ◽  
Paulo Roberto WANDER
Keyword(s):  
Malachite Green ◽  
Retention Time ◽  
High Surface ◽  
High Surface Area ◽  
Exchange Capacity ◽  
Montmorillonite Clay ◽  
Malachite Green Dye ◽  
Low Levels ◽  
High Concentrations

Removal of malachite green dye by adsorption from aqueous solution using montmorillonite clay is reported in this work. A malachite green dye is a cationic widely used in textile industries. Due to its persistence in the aquatic environment, it becomes a problem for aquatic and terrestrial organisms. This dye can be adsorbed through various techniques, but high acquisition and operating costs preclude widespread use. Several adsorbents are available in the market, but the most outstanding are the clays, especially the montmorillonites. These clays are finely divided material ( 0.002 mm), and its adsorption properties are continuously investigated. Types of clays 2:1 (two tetrahedral to one octahedral) are called expandables. The montmorillonite has a potential for dyes removal in wastewater due to the high surface area, porosity with excellent cation exchange capacity conferring its adsorbent property. This work aims to use the montmorillonite as an adsorption system in stages to textile decolorization effluent, composed of malachite green dye, reproduced in the laboratory. The characterization of the clay gives high purity and is used as adsorbent of good quality and efficiency. The retention of dyes in the system composed of montmorillonite arranged in separation stages was efficient. The effect of dye concentration and retention time are the most important parameters used in this study. High concentrations and retention time below 24 hours resulted in low levels of removal (25%). On the other hand, the low level of initial concentration increases removal efficiency (57%). Thus, the results obtained in this work allow concluding that montmorillonite is able to removal malachite green dye.

scholarly journals Preparation and characterization of activated carbons from albizia saman pod

2017 ◽  
Vol 36 (3) ◽  
pp. 44-53
Author(s):  
G. D. Akpen ◽  
M. I. Aho ◽  
N. Baba
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Activated Carbons ◽  
High Surface ◽  
High Surface Area ◽  
Volatile Matter ◽  
Sieve Analysis ◽  
Albizia Saman ◽  
Temperature Surface

Activated carbon was prepared from the pods of Albizia saman for the purpose of converting the waste to wealth. The pods were thoroughly washed with water to remove any dirt, air- dried and cut into sizes of 2-4 cm. The prepared pods were then carbonised in a muffle furnace at temperatures of 4000C, 5000C, 6000C ,7000C and 8000C for 30 minutes. The same procedure was repeated for 60, 90, 120 and 150 minutes respectively. Activation was done using impregnationratios of 1:12, 1:6, 1:4, 1:3, and 1:2 respectively of ZnCl2 to carbonised Albizia saman pods by weight. The activated carbon was then dried in an oven at 1050C before crushing for sieve analysis. The following properties of the produced Albizia saman pod activated carbon (ASPAC) were determined: bulk density, carbon yield, surface area and ash, volatile matter and moisture contents. The highest surface area of 1479.29 m2/g was obtained at the optimum impregnation ratio, carbonization time and temperature of 1:6, 60 minutes and 5000C respectively. It was recommended that activated carbon should be prepared from Albizia saman pod with high potential for adsorption of pollutants given the high surface area obtained.Keywords: Albizia saman pod, activated carbon, carbonization, temperature, surface area

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