scholarly journals Surface Modification and Characterization of Coconut Shell-Based Activated Carbon Subjected to Acidic and Alkaline Treatments

2017 ◽  
Vol 4 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Tan I. A. W. ◽  
Abdullah M. O. ◽  
Lim L. L. P. ◽  
Yeo T. H. C.
Keyword(s):  
Activated Carbon ◽  
Surface Morphology ◽  
Surface Chemistry ◽  
Pore Structure ◽  
Surface Area ◽  
Functional Groups ◽  
Activated Carbons ◽  
Coconut Shell ◽  
Bet Surface Area ◽  
Textural Characterization

Activated carbon derived from agricultural biomass has been increasingly recognized as a multifunctional material for various applications according to its physicochemical characteristics. The application of activated carbon in adsorption process mainly depends on the surface chemistry and pore structure which is greatly influenced by the treatment method. This study aims to compare the textural characteristics, surface chemistry and surface morphology of coconut shell-based activated carbon modified using chemical surface treatments with hydrochloric acid (HCl) and sodium hydroxide (NaOH). The untreated and treated activated carbons were characterized for their physical and chemical properties including the Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and textural characterization. The FTIR spectra displayed bands confirming the presence of carboxyl, hydroxyl and carbonyl functional groups. The Brunauer–Emmett–Teller (BET) surface area of the untreated activated carbon was 436 m2/g whereas the surface area of the activated carbon modified using 1M NaOH, 1M HCl and 2M HCl was 346, 525 and 372 m2/g, respectively. SEM micrographs showed that many large pores in a honeycomb shape were clearly found on the surface of 1M HCl sample. The pore structure of the activated carbon treated with 2M HCl and NaOH was partially destroyed or enlarged, which decreased the BET surface area. The modification of the coconut shell-based activated carbon with acidic and alkaline treatments has successfully altered the surface functional groups, surface morphology and textural properties of the activated carbon which could improve its adsorptive selectivity on a certain adsorbate.

Preparation of Capacitor’s Electrode from Coconut Shell

2014 ◽  
Vol 875-877 ◽  
pp. 1585-1589
Author(s):  
Arenst Andreas Arie ◽  
Joong Kee Lee
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Electrode Materials ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Coconut Shell ◽  
Bet Surface Area ◽  
Type I ◽  
Activation Temperature ◽  
Bet Analysis

Activated carbons were prepared from coconut shell by chemical activation method and utilized as electrode materials for electrochemical double layer capacitor (EDLC). A preliminary characteristic of activated carbon from coconut shell includes the Brunnaeur Emmett Teller (BET) analysis and cyclic voltammetry measurements. The BET surface area is not affected by the variation of activation temperature as both of the samples showed BET surface area of about 850-870 m2g-1. The N2 adsorption–desorption isotherms showed that the sample exhibited type I characteristics according to IUPAC classification, which confirms its micro-porosity. Compared with the un-activated carbon samples, the activated ones exhibited the better electrochemical properties with a specific capacitance of 150 F g−1 at a scan rate of 2 mV s−1. The good performance of activated carbon is attributed to the enhancement of surface area due to the KOH pretreatment which can open new pores accessible for the ionic transport

Characterization of Low-Pressure Nitrogen Plasma Discharge and Pre-Oxidation on the Surface Characteristics of Activated Carbons

2020 ◽  
Vol 998 ◽  
pp. 102-107
Author(s):  
Ria Grace Abdon ◽  
Top Archie Dela Peña ◽  
Camille Punongbayan ◽  
John Achilles Ricafrente
Keyword(s):  
Activated Carbon ◽  
Surface Morphology ◽  
Surface Area ◽  
Functional Groups ◽  
Activated Carbons ◽  
Low Pressure ◽  
Plasma Discharge ◽  
Total Surface Area ◽  
Micropore Volume ◽  
Nitrogen Plasma

Commercial activated carbon (CAC) was modified using low-pressure radio frequency nitrogen plasma discharge (NPD) operating at 0.3 mbar and 40 kHz. The surface chemistry of CAC was modified using HNO3 pre-oxidation to possibly influence the reactivity of NPD. The results of x-ray photoelectron spectroscopy (XPS) suggested that pre-oxidation reduces aromaticity, generates aliphatic carbons (C-C and C-H), and increases carboxylic functional groups (COOH) which probably enhances the nitrogen plasma functionalization based on the N/C ratio for CAC-O-P (4.29 %) compared to CAC-P (2.88 %). FTIR was used to confirm such effects of pre-oxidation from the functional groups present on the carbon surface. The total surface area was identified using Langmuir and Brunauer–Emmett–Teller (BET) N2 adsorption isotherms at 77 K. Both pre-oxidation and plasma treatment caused an increase in the surface area of CAC up to 150 percent. Carbon t-plot method was used to determine the micropore volume, micropore area, and external surface area. The total surface area of each activated carbon was mostly constituted of micropore area which was identified to be directly proportional to the micropore volume. Scanning electron microscope (SEM) confirms the destruction of the surface morphology for CAC-O that might have caused the increase in surface area. Development of surface threadlike structures were observed for the NPD treated CAC-O. NPD favors the development of NH2 functionalities and reduces the aromaticity of activated carbons while enhancing the surface morphology and the surface area.

The influential factors towards graphene oxides removal by activated carbons: Activated functional groups vs BET surface area

2018 ◽  
Vol 271 ◽  
pp. 142-150 ◽  
Author(s):  
Ju Sun ◽  
Xia Liu ◽  
Shengxia Duan ◽  
Ahmed Alsaedi ◽  
Fengsong Zhang ◽  
...  
Keyword(s):  
Surface Area ◽  
Functional Groups ◽  
Activated Carbons ◽  
Influential Factors ◽  
Bet Surface Area ◽  
Graphene Oxides

A comparison of different activated carbon performances on catalytic ozonation of a model azo reactive dye

2012 ◽  
Vol 66 (1) ◽  
pp. 179-184 ◽  
Author(s):  
Ş. Gül ◽  
O. Eren ◽  
Ş. Kır ◽  
Y. Önal
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Activated Carbons ◽  
High Surface ◽  
High Surface Area ◽  
Reactive Dye ◽  
Catalytic Ozonation ◽  
Bet Surface Area ◽  
Solution Ph ◽  
Pore Properties

The objective of this study is to compare the performances of catalytic ozonation processes of two activated carbons prepared from olive stone (ACOS) and apricot stone (ACAS) with commercial ones (granular activated carbon-GAC and powder activated carbon-PAC) in degradation of reactive azo dye (Reactive Red 195). The optimum conditions (solution pH and amount of catalyst) were investigated by using absorbencies at 532, 220 and 280 nm wavelengths. Pore properties of the activated carbon (AC) such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by N2 adsorption. The highest BET surface area carbon (1,275 m2/g) was obtained from ACOS with a particle size of 2.29 nm. After 2 min of catalytic ozonation, decolorization performances of ACOS and ACAS (90.4 and 91.3%, respectively) were better than that of GAC and PAC (84.6 and 81.2%, respectively). Experimental results showed that production of porous ACs with high surface area from olive and apricot stones is feasible in Turkey.

Physical and Chemical Activation Effect on Activated Carbon Prepared from Local Pineapple Waste

2014 ◽  
Vol 699 ◽  
pp. 87-92 ◽  
Author(s):  
Abdul Rahim Yacob ◽  
Adlina Azmi ◽  
Mohd Khairul Asyraf Amat Mustajab
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Surface Area ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Bet Surface Area ◽  
Activation Effect ◽  
Pineapple Waste ◽  
Pineapple Peel ◽  
Physical And Chemical

The characteristics and quality of activated carbons prepared depending on the chemical and physical properties of the starting materials and the activation method used. In this study, activated carbon prepared using pineapple waste. Three parts of pineapple waste which comprises of peel, crown and leaf were studied. For comparison activated carbon were prepared by both physical and chemical activation respectively. Three types of chemicals were used, phosphoric acid (H3PO4), sulphuric acid (H2SO4), and potassium hydroxide (KOH). The preparation includes carbonization at 200°C and activation at the 400°C using muffle furnace. The chemical characterization of the activated carbon was carried out using Thermogravimetric analysis (TGA), Nitrogen gas adsorption analysis and Fourier transform infrared (FTIR). The highest BET surface area was achieved when the pineapple peel soaked in 20% phosphoric acid with a surface area of 1115 m2g-1. FTIR analysis indicates that the reacted pineapple waste successfully converted into activated carbons.

scholarly journals Carbonization Temperature Effect over Activated Carbon Porosity Derived from Industrial Processing Waste

2019 ◽  
Vol 2 (3) ◽  
pp. 1205-1209
Author(s):  
Hasan Sayğılı
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Pore Volume ◽  
Activated Carbons ◽  
Waste Product ◽  
Total Pore Volume ◽  
Carbonization Temperature ◽  
Bet Surface Area ◽  
Processing Waste ◽  
Industrial Processing

The influence of carbonization temperature (CT) on pore properties of the prepared activated carbon using lentil processing waste product (LWP) impregnated with potassium carbonate was studied. Activated carbons (ACs) were obtained by impregnation with 3:1 ratio (w/w) K2CO3/LWP under different carbonization temperatures at 600, 700, 800 and 900 oC for 1h. Activation at low temperature represented that micropores were developed first and then mesoporosity developed, enhanced up to 800 oC and then started to decrease due to possible shrinking of pores. The optimum temperature for LWP was found to be around 800 oC on the basis of total pore volume and the Brunauer-Emmett-Teller (BET) surface area. The optimum LWPAC sample was found with a CT of 800 oC, which gives the highest BET surface area and pore volume of 1875 m2/g and 0.995 cm3/g, respectively.

scholarly journals Characterization of Activated Carbons from Oil-Palm Shell by CO2Activation with No Holding Carbonization Temperature

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
S. G. Herawan ◽  
M. S. Hadi ◽  
Md. R. Ayob ◽  
A. Putra
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Oil Palm ◽  
Pyrolysis Temperature ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Surface Characteristics ◽  
Bet Surface Area ◽  
Preparation Time

Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced.

Characteristics of Potassium Acetate - Activated Coconut Shell Carbon

2014 ◽  
Vol 1043 ◽  
pp. 193-197
Author(s):  
Noor Shawal Nasri ◽  
Jibril Mohammed ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Dadum Hamza ◽  
Husna Mohd. Zain ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Chemical Activation ◽  
Potassium Acetate ◽  
Lower Surface ◽  
The Other ◽  
Toxic Waste ◽  
Coconut Shell ◽  
Bet Surface Area ◽  
Physical Activation

There is significant portion of agricultural wastes in the world posing environmental challenge; however, they could be converted into useful products like activated carbon. In this study, coconut shell based carbons were synthesized using chemical activation with potassium acetate (PAAC), potassium hydroxide (PHAC) and physical activation by CO2 (CSAC). The properties of potassium acetate-activated carbon were characterized and the results were compared with the other activation methods. The pyrolysis temperature of 700°C for 2h yielded 32% of char. The BET surface area and pore volume of PAAC are 622m2/g and 0.31cm3/g; while 369m2/g and 0.19cm3/g, and 1354m2/g and 0.61cm3/g were recorded for CSAC and PHAC, respectively. CSAC yielded lower surface area with approximately 88% micropores. On the other hand, PAAC yielded higher surface area with approximately 50% of both micropores and mesopores, whereby this heteroporous property would suffice for a wider range of application. From the Fourier Transform Infrared Spectroscopy analysis, hydroxyls, alkenes, carbonyls and aromatics functional groups were identified with more prominent peaks on the chemically activated porous carbons. From thermogravimetric analysis (TGA), lignin decomposition occurred in a wider temperature range (390-650°C). The properties of PAAC could offer a sustainable means for treatment of toxic waste streams.

Preparation of Activated Carbon of Lignin from Straw Pulping by Chemical Activation Using Potassium Carbonate

2011 ◽  
Vol 704-705 ◽  
pp. 517-522 ◽  
Author(s):  
Xiao Juan Jin ◽  
Zhi Ming Yu ◽  
Gao Jiang Yan ◽  
Wu Yu
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Iodine Number ◽  
Surface Area ◽  
Potassium Carbonate ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Bet Surface Area ◽  
Chemical Agent ◽  
Optimum Conditions

Activated carbons were prepared through chemical activation of lignin from straw pulping precursor using potassium carbonate as the chemical agent. Effects of activated temperature, K2CO3/lignin ratio and the activated time on the yield, Iodine number of activated carbon were investigated. Experimental results indicated that the optimum conditions were as follow: activated temperature 800°C, K3CO3(40% concentration) /lignin ratio 5: l, activated time 50min. These conditions allowed us to obtain a BET surface area of 1104 m2/g, including the external or non-microporous surface of 417 m2/g，Amount of methylene blue adsorption, Iodine number and the yield of activated carbon prepared under optimum conditions were 10.6mL/0.lg,1310 mg/g and 19.75%, respectively.

Assessment of various carbon-based adsorbents for separation of BTX from aqueous solution

2015 ◽  
Vol 15 (3) ◽  
pp. 649-655 ◽  
Author(s):  
Husam Faiz Haddad ◽  
Azhagapillai Prabhu ◽  
Ahmed Al Shoaibi ◽  
Chandrasekar Srinivasakannan
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Functional Groups ◽  
Activated Carbons ◽  
Chemical Properties ◽  
Bet Surface Area ◽  
Kinetics Of Adsorption ◽  
Physico Chemical ◽  
Benzene Toluene ◽  
Kinetics Of

The adsorption of benzene, toluene and xylene (BTX) was investigated covering different types of commercially available activated carbons with varied surface area and surface functional groups. The physico-chemical properties were characterized by Brunauer–Emmett–Teller (BET) surface area analysis, Fourier transform infrared (FTIR) spectroscopy and the Boehm titration method. Experiments to assess the adsorption isotherms and kinetics of adsorption were performed and the results are presented. An increase in the surface acid functional groups was found to decrease the adsorption capacity, with the highest adsorption capacity corresponding to carbon with lowest acid functionality.

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