scholarly journals Activated Carbon from Corncobs Doped with RuO2 as Biobased Electrode Material

2021 ◽  
Vol 2 (3) ◽  
pp. 324-343
Author(s):  
Viola Hoffmann ◽  
Catalina Rodriguez Correa ◽  
Saskia Sachs ◽  
Andrea del Pilar Sandoval-Rojas ◽  
Mo Qiao ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Electrochemical Properties ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Xrd Analysis ◽  
High Specific Surface Area ◽  
Carbon Surface ◽  
Physico Chemical ◽  
Electrochemical Double Layer Capacitors ◽  
Electrochemical Double Layer

Bio-based activated carbons with very high specific surface area of >3.000 m² g−1 (based on CO2 adsorption isotherms) and a high proportion of micropores (87% of total SSA) are produced by corncobs via pyrolysis and chemical activation with KOH. The activated carbon is further doped with different proportions of the highly pseudocapacitive transition metal oxide RuO2 to obtain enhanced electrochemical properties and tune the materials for the application in electrochemical double-layer capacitors (EDLC) (supercapacitors). The activated carbon and composites are extensively studied regarding their physico-chemical and electrochemical properties. The results show that the composite containing 40 wt.% RuO2 has an electric conductivity of 408 S m−1 and a specific capacitance of 360 Fg−1. SEM-EDX, XPS, and XRD analysis confirm the homogenous distribution of partly crystalline RuO2 particles on the carbon surface, which leads to a biobased composite material with enhanced electrochemical properties.

scholarly journals Comparison of Surface and Structural Properties of Carbonaceous Materials Prepared by Chemical Activation of Tomato Paste Waste: The Effects of Activator Type and Impregnation Ratio

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Nurgul Ozbay ◽  
Adife Seyda Yargic
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Low Cost ◽  
Chemical Activation ◽  
Nitrogen Adsorption ◽  
Xrd Analysis ◽  
Point Of Zero Charge ◽  
Activation Process ◽  
X Ray ◽  
Tomato Paste

Activated carbons were prepared by carbonization of tomato paste processing industry waste at 500°C followed by chemical activation with KOH, K2CO3, and HCl in N2 atmosphere at low temperature (500°C). The effects of different activating agents and impregnation ratios (25, 50, and 100 wt.%) on the materials’ characteristics were examined. Precursor, carbonized tomato waste (CTW), and activated carbons were characterized by using ultimate and proximate analysis, thermogravimetric analysis (TG/DTG), Fourier transform-infrared (FT-IR) spectroscopy, X-ray fluorescence (XRF) spectroscopy, point of zero charge measurements (pHPZC), particle size analyzer, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, nitrogen adsorption/desorption isotherms, and X-ray diffraction (XRD) analysis. Activation process improved pore formation and changed activated carbons’ surface characteristics. Activated carbon with the highest surface area (283 m3/g) was prepared by using 50 wt.% KOH as an activator. According to the experimental results, tomato paste waste could be used as an alternative precursor to produce low-cost activated carbon.

scholarly journals The interaction of metallic ions onto activated carbon surface using computational chemistry software

2020 ◽  
Vol 38 (5-6) ◽  
pp. 191-204
Author(s):  
AL Paredes-Doig ◽  
A Pinedo-Flores ◽  
J Aylas-Orejón ◽  
D Obregón-Valencia ◽  
MR Sun Kou
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Electron Density ◽  
Activated Carbons ◽  
Surface Acidity ◽  
Chemical Activation ◽  
Carbon Surface ◽  
Maximum Adsorption Capacity ◽  
Metallic Ions ◽  
Oxidized Activated Carbon

Activated carbon was prepared from the seeds of aguaje palm ( Mauritia flexuosa L.f.) by a chemical activation with phosphoric acid. This activated carbon was used for adsorbing metal ions: Pb(II), Cd(II), and Cr(III). To understand the mechanism of adsorption of these heavy metals (Cr, Cd, and Pb), the activated carbon surface was oxidized with nitric acid (1 M) increasing the oxygenated surface groups showing an increasing in their adsorption capacities of these metals. The oxidized activated carbon slightly increased the maximum adsorption capacity to 5–7%. The order of adsorption for unoxidized and oxidized activated carbons was Pb> Cd> Cr. This experimental information was corroborated by molecular modeling program Hyperchem 8 based adsorption mainly on two factors: the electron density and orbitals—highest occupied molecular orbital and lowest unoccupied molecular orbital.Activated carbons were characterized by adsorption/desorption of N2, obtaining an increase of microporous surface area for oxidized activated carbon. An increase of surface acidity and a reduction of isoelectric points were observed in oxidized activated carbon. According to these results, the adsorption of metal ions is favored in contact with an oxidized activated carbon, which has more amount of phenolic and carboxylic functional groups. Similarly, decreasing the isoelectric point indicates that the surface has a higher negative charge. The surface information was corroborated by Hyperchem, which indicates that the surface of the oxidized activated carbon has a higher electron density, indicating a larger amount of electrons on its surface, which means the surface of oxidized activated carbon charges negatively and thereby attracts metal ions.

scholarly journals Production and Characterization of Activated Carbon from Baobab Fruit Shells by Chemical Activation Using ZnCl2, H3PO4 and KOH

2021 ◽  
Vol 2129 (1) ◽  
pp. 012009
Author(s):  
R Nedjai ◽  
N A Kabbashi ◽  
M Z Alam ◽  
M F R Al-Khatib
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Xrd Analysis ◽  
Surface Characteristic ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Characterization Of Activated Carbon

Abstract Chemical agents have a good influence on the formation of activated carbons, surface characteristic, and its adsorption properties. In this study, the effect of activating agents (ZnCl2, KOH, and H3PO4) on baobab fruit shell (BFS) were evaluated. The characteristics of the baobab fruit shell based activated carbon (BF-ACs) were evaluated through the yield and iodine number. BF-ACs were also characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and nitrogen (N2) adsorption. SEM analysis illustrates those porous structures formed on the surface of BF-ACs were with different sizes. The XRD analysis show that the main structures of BF-ACs are amorphous. FT-IR data demonstrates the presence of different surface groups on the produced BF-ACs. Among activating agent, the KOH was observed to the most appropriate for the production of activated carbon with a large surface area (1029.44 m2/g) from baobab fruit shell.

scholarly journals Physico-chemical characterization of powdered activated carbons obtained by thermo-chemical conversion of brown municipal waste

2011 ◽  
Vol 65 (3) ◽  
pp. 241-247
Author(s):  
Milan Momcilovic ◽  
Milovan Purenovic ◽  
Milena Miljkovic ◽  
Aleksandar Bojic ◽  
Aleksandra Zarubica ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Pore Distribution ◽  
Municipal Waste ◽  
Horse Chestnut ◽  
Physico Chemical ◽  
Developed Surface ◽  
Oxygen Groups

Cones of the European Black pine and Horse chestnut kernel, regarded as brown municipal waste, was utilized in this work as a precursor for powdered activated carbons. Chemical activation was employed at 500?C in inert atmosphere of nitrogen. Standard physico-chemical analyses were performed to examine obtained products. FTIR method was employed to determine fuctional groups which were found to be typical for activated carbons. Acidic oxygen groups were quantitatively determined using Boehm titrations. It was established that carboxylic groups on pine cone activated carbon, and phenolic groups on chestnut kernel activated carbon were dominant from all acidic oxygen groups. Since both contact pH and pHPZC were determined to be fairly acidic, it could be concluded that obtained activated carbons belong to L-type. Shape and layout of micrometer dimensioned particles were observed by scanning electron microscopy. Particles of different shapes and dimensions along with small cracks and wide crevices and voids were noticed. Textural analysis was used to determine specific surface area and pore distribution of obtained activated carbons. Obtained products possess highly developed surface area and wide pore distribution.

scholarly journals The influence of active carbon contaminants on the ozonation mechanism interpretation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lilla Fijołek ◽  
Joanna Świetlik ◽  
Marcin Frankowski
Keyword(s):  
Activated Carbon ◽  
Active Carbon ◽  
Alkali Metals ◽  
Activated Carbons ◽  
Carbon Surface ◽  
Bulk Solution ◽  
Ozone Decomposition ◽  
Reaction Products ◽  
Treatment Technology ◽  
Carbon Impurities

AbstractIn water treatment technology, activated carbons are used primarily as sorbents to remove organic impurities, mainly natural organic matter, but also as catalysts in the ozonation process. Commercially available activated carbons are usually contaminated with mineral substances, classified into two main groups: alkali metals (Ca, Na, K, Li, Mg) and multivalent metals (Al, Fe, Ti, Si). The presence of impurities on the carbon surface significantly affects the pHpzc values determined for raw and ozonated carbon as well as their acidity and alkalinity. The scale of the observed changes strongly depends on the pH of the ozonated system, which is related to the diffusion of impurities from the carbon to the solution. In an acidic environment (pH 2.5 in this work), the ozone molecule is relatively stable, yet active carbon causes its decomposition. This is the first report that indirectly indicates that contaminants on the surface of activated carbon (multivalent elements) contribute to the breakdown of ozone towards radicals, while the process of ozone decomposition by purified carbons does not follow the radical path in bulk solution. Carbon impurities also change the distribution of the reaction products formed by organic pollutants ozonation, which additionally confirms the radical process. The study showed that the use of unpurified activated carbon in the ozonation of succinic acid (SA) leads to the formation of a relatively large amount of oxalic acid (OA), which is a product of radical SA degradation. On the other hand, in solutions with purified carbon, the amount of OA generated is negligible.

scholarly journals Computer Analysis of the Effect of Activation Temperature on the Microporous Structure Development of Activated Carbon Derived from Common Polypody

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2951
Author(s):  
Mirosław Kwiatkowski ◽  
Jarosław Serafin ◽  
Andy M. Booth ◽  
Beata Michalkiewicz
Keyword(s):  
Activated Carbon ◽  
Porous Structure ◽  
Computer Analysis ◽  
Density Functional ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Geometrical Parameters ◽  
Activation Process ◽  
Microporous Structure ◽  
Activation Temperature

This paper presents the results of a computer analysis of the effect of activation process temperature on the development of the microporous structure of activated carbon derived from the leaves of common polypody (Polypodium vulgare) via chemical activation with phosphoric acid (H3PO4) at activation temperatures of 700, 800, and 900 °C. An unconventional approach to porous structure analysis, using the new numerical clustering-based adsorption analysis (LBET) method together with the implemented unique gas state equation, was used in this study. The LBET method is based on unique mathematical models that take into account, in addition to surface heterogeneity, the possibility of molecule clusters branching and the geometric and energy limitations of adsorbate cluster formation. It enabled us to determine a set of parameters comprehensively and reliably describing the porous structure of carbon material on the basis of the determined adsorption isotherm. Porous structure analyses using the LBET method were based on nitrogen (N2), carbon dioxide (CO2), and methane (CH4) adsorption isotherms determined for individual activated carbon. The analyses carried out showed the highest CO2 adsorption capacity for activated carbon obtained was at an activation temperature of 900 °C, a value only slightly higher than that obtained for activated carbon prepared at 700 °C, but the values of geometrical parameters determined for these activated carbons showed significant differences. The results of the analyses obtained with the LBET method were also compared with the results of iodine number analysis and the results obtained with the Brunauer–Emmett–Teller (BET), Dubinin–Radushkevich (DR), and quenched solid density functional theory (QSDFT) methods, demonstrating their complementarity.

scholarly journals Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review

2012 ◽  
Vol 1 (3) ◽  
pp. 75 ◽  
Author(s):  
W.D.P Rengga ◽  
M. Sudibandriyo ◽  
M Nasikin
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Chemical Activation ◽  
High Energy ◽  
Hydrogen Gas ◽  
Agricultural Product ◽  
Adsorption Method ◽  
Modified Activated Carbon ◽  
Nano Size ◽  
Formaldehyde Adsorption

Gas storage is a technology developed with an adsorptive storage method, in which gases are stored as adsorbed components on the certain adsorbent. Formaldehyde is one of the major indoor gaseous pollutants. Depending on its concentration, formaldehyde may cause minor disorder symptoms to a serious injury. Some of the successful applications of technology for the removal of formaldehyde have been reported. However, this paper presents an overview of several studies on the elimination of formaldehyde that has been done by adsorption method because of its simplicity. The adsorption method does not require high energy and the adsorbent used can be obtained from inexpensive materials. Most researchers used activated carbon as an adsorbent for removal of formaldehyde because of its high adsorption capacity. Activated carbons can be produced from many materials such as coals, woods, or agricultural waste. Some of them were prepared by specific activation methods to improve the surface area. Some researchers also used modified activated carbon by adding specific additive to improve its performance in attracting formaldehyde molecules. Proposed modification methods on activation and additive impregnated carbon are thus discussed in this paper for future development and improvement of formaldehyde adsorption on activated carbon. Specifically, a waste agricultural product is chosen for activated carbon raw material because it is renewable and gives an added value to the materials. The study indicates that the performance of the adsorption of formaldehyde might be improved by using modified activated carbon. Bamboo seems to be the most appropriate raw materials to produce activated carbon combined with applying chemical activation method and addition of metal oxidative catalysts such as Cu or Ag in nano size particles. Bamboo activated carbon can be developed in addition to the capture of formaldehyde as well as the storage of adsorptive hydrogen gas that supports renewable energy. Keywords: adsorption; bamboo; formaldehyde; modified activated carbon; nano size particles

PREPARATION AND CHARACTERIZATION OF ACTIVATED CARBON FROM OIL PALM EMPTY FRUIT BUNCH WASTES USING ZINC CHLORIDE

2015 ◽  
Vol 74 (11) ◽  
Author(s):  
Riry Wirasnita ◽  
Tony Hadibarata ◽  
Abdull Rahim Mohd Yusoff ◽  
Zainab Mat Lazim
Keyword(s):  
Activated Carbon ◽  
Zinc Chloride ◽  
Oil Palm ◽  
Active Sites ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Proximate Analysis ◽  
Infrared Spectrometry ◽  
Empty Fruit Bunch

An oil palm empty fruit bunch-derived activated carbon has been successfully produced by chemical activation with zinc chloride and without chemical activation. The preparation was conducted in the tube furnace at 500oC for 1 h. The surface structure and active sites of activated carbons were characterized by means of Fourier transform infrared spectrometry and field emission scanning electron microscopy. The proximate analysis including moisture content, ash content, bulk density, pH, and pH at zero charge was conducted to identify the psychochemical properties of the adsorbent. The results showed that the zinc chloride-activated carbon has better characteristics compared to the carbon without chemical activation.  

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