Effects of Pre-Carbonization on Structure and Electrochemical Performances of Amphiphilic Carbonaceous Material-Based Activated Carbons

Activated carbons to be used as electrode in electrochemical double-layer capacitors were fabricated using amphiphilic carbonaceous material (ACM) as precursor. To study the significance of functional groups and microcrystalline of the precursor in preparing AC, we applied pre-carbonization upon the ACM under different conditions to control these two parameters in this paper. FTIR and XPS spectra showed functional groups on the precursors decreased as the increase of pre-carbonization temperature. After carbonization at 800 °C, the growth of graphitic microcrystallites was noticeable. Porous structure parameters of final ACs inferred that the functional groups on the precursors have a more significant effect than microcrystalline size on formation of mesopores during activation process not only for its role as active sites but also the homogeneous activation profited from the solubility of samples in alkaline solutions. The sample AC0 with almost half mesopores showed the best electrochemical behavior with a specific gravimetric capacitance of 255 F/g at current density of 1000mA/g and kept rectangular shape cyclic voltammetry curve even at scan rate high as 400 mV/s.

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The Analysis of Pore Development and Formation of Surface Functional Groups in Bamboo-Based Activated Carbon during CO2 Activation

Molecules ◽

10.3390/molecules26185641 ◽

2021 ◽

Vol 26 (18) ◽

pp. 5641

Author(s):

Krittamet Phothong ◽

Chaiyot Tangsathitkulchai ◽

Panuwat Lawtae

Keyword(s):

Activated Carbon ◽

Functional Groups ◽

Active Sites ◽

Activated Carbons ◽

Carbonization Temperature ◽

Activation Process ◽

Activation Time ◽

Oxygen Functional Groups ◽

Porous Properties ◽

Activation Conditions

Pore development and the formation of oxygen functional groups were studied for activated carbon prepared from bamboo (Bambusa bambos) using a two-step activation with CO2, as functions of carbonization temperature and activation conditions (time and temperature). Results show that activated carbon produced from bamboo contains mostly micropores in the pore size range of 0.65 to 1.4 nm. All porous properties of activated carbons increased with the increase in the activation temperature over the range from 850 to 950 °C, but decreased in the temperature range of 950 to 1000 °C, due principally to the merging of neighboring pores. The increase in the activation time also increased the porous properties linearly from 60 to 90 min, which then dropped from 90 to 120 min. It was found that the carbonization temperature played an important role in determining the number and distribution of active sites for CO2 gasification during the activation process. Empirical equations were proposed to conveniently predict all important porous properties of the prepared activated carbons in terms of carbonization temperature and activation conditions. Oxygen functional groups formed during the carbonization and activation steps of activated carbon synthesis and their contents were dependent on the preparation conditions employed. Using Boehm’s titration technique, only phenolic and carboxylic groups were detected for the acid functional groups in both the chars and activated carbons in varying amounts. Empirical correlations were also developed to estimate the total contents of the acid and basic groups in activated carbons in terms of the carbonization temperature, activation time and temperature.

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Activated Carbons Derived from Teak Sawdust-Hydrochars for Efficient Removal of Methylene Blue, Copper, and Cadmium from Aqueous Solution

Water ◽

10.3390/w11122581 ◽

2019 ◽

Vol 11 (12) ◽

pp. 2581 ◽

Cited By ~ 4

Author(s):

Hai Duy Nguyen ◽

Hai Nguyen Tran ◽

Huan-Ping Chao ◽

Chu-Ching Lin

Keyword(s):

Methylene Blue ◽

Surface Area ◽

Functional Groups ◽

Activated Carbons ◽

Electrostatic Force ◽

Chemical Activation ◽

Hydrothermal Process ◽

Weight Ratio ◽

Activation Process ◽

Complexation Reaction

Recycling materials from waste has been considered one of the essential principles in the context of sustainable development. In this study, we used teak sawdust as the feedstock material to synthesize activated carbon (AC) samples and evaluated the application of these ACs in the adsorption of methylene blue (MB), Cd(II), and Cu(II). The sawdust was carbonized by a hydrothermal process, followed by chemical activation using K2CO3 or ZnCl2 in various weight ratios. The AC samples produced were characterized by scanning electron microscopy, Brunauer–Emmett–Teller surface area analysis, Fourier-transform infrared spectroscopy, X-ray photon spectroscopy, and mass titration of acidic groups. The characterization results showed that the ACs did possess a high surface area and rich oxygen-containing functional groups. The adsorptive amounts of MB, Cd(II), and Cu(II) on ACs approximately increased with the concentration of the activating agent: when the weight ratio of the carbonaceous material to ZnCl2 reached 1.75, the maximum adsorption capacities for MB, Cd(II), and Cu(II) were achieved, and the values were 614, 208, and 182 mg/g, respectively. The level of oxygen-containing functional groups was identified as an important factor in determining the adsorptive amounts. While the electrostatic force was the primary pathway that led to the adsorption of the tested contaminants onto the AC, the complexation reaction was a vital mechanism responsible for the adsorptive interaction between ACs and Cu(II). The high adsorption capacity of the synthetic ACs for MB, Cd(II), and Cu(II) demonstrated in this study points out the potential application of biomass-residue-based adsorbents prepared via a coupled hydrothermal carbonization/chemical activation process in wastewater treatment.

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Catalytic Effect of NaCl on the Improvement of the Physicochemical Structure of Coal-Based Activated Carbons for SO2 Adsorption

Processes ◽

10.3390/pr7060338 ◽

2019 ◽

Vol 7 (6) ◽

pp. 338 ◽

Cited By ~ 3

Author(s):

Dongdong Liu ◽

Rui Su ◽

Zhengkai Hao ◽

Xiaoman Zhao ◽

Boyin Jia ◽

...

Keyword(s):

Functional Groups ◽

Active Sites ◽

Catalytic Effect ◽

High Efficiency ◽

Activated Carbons ◽

Rapid Development ◽

Adsorptive Capacity ◽

Oxygen Functional Groups ◽

So2 Adsorption ◽

Physicochemical Structure

The utilization of coal-based activated carbons focuses on improving the physicochemical structure for achieving high-capacity. Herein, the catalytic effect of NaCl (1 and 3 wt%) in the presence of oxygen functional groups on the improvement of the physicochemical structure of coal-based activated carbons is studied in this work. A large quantity of Na can be retained in 1NaJXO and 3NaJXO with the presence of oxygen functional groups to promote further its catalytic characteristics during pyrolysis, resulting in the disordered transformation of the carbon structure. In addition, the development of micropores is mainly affected by the distribution and movement of Na catalyst, whereas the growth of mesopores is mainly influenced by the evolution of oxygen functional groups. Then, the active sites of 3NaJXO-800 can no longer be consumed preferentially in the presence of Na catalyst during subsequent CO2 activation to facilitate the sustained disordered conversion of the microstructure and the rapid development of the micropores, resulting in the obvious high SBET value as activation proceeds. And the high SBET/burn-off ratio value (41.48 m2∙g−1/%) of 3NaJXO-800 with a high value of SBET (1995.35 m2∙g−1) at a low burn-off value (48.1%) can be obtained, presenting the high efficiency of pore formation. Finally, the SO2 adsorption efficiency of 3NaJXO-800-48.1 maintains at 100% within 90 min. After 180 min, 3NaJXO-800-48.1 still presents a high adsorptive capacity (140.2 mg/g). It is observed that a large micropore volume in the case of hierarchical pore structure necessarily assures optimal adsorption of SO2.

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

Materials ◽

10.3390/ma14112951 ◽

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.

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High Capacity and Fast Kinetics of Potassium-Ion Batteries Boosted by Nitrogen-Doped Mesoporous Carbon Spheres

Nano-Micro Letters ◽

10.1007/s40820-021-00706-3 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Jiefeng Zheng ◽

Yuanji Wu ◽

Yong Tong ◽

Xi Liu ◽

Yingjuan Sun ◽

...

Keyword(s):

Mesoporous Carbon ◽

Active Sites ◽

Carbon Materials ◽

Potassium Ion ◽

High Rate ◽

Electrochemical Performances ◽

Carbon Spheres ◽

Fast Kinetics ◽

Nitrogen Doped ◽

Economic Price

AbstractIn view of rich potassium resources and their working potential, potassium-ion batteries (PIBs) are deemed as next generation rechargeable batteries. Owing to carbon materials with the preponderance of durability and economic price, they are widely employed in PIBs anode materials. Currently, porosity design and heteroatom doping as efficacious improvement strategies have been applied to the structural design of carbon materials to improve their electrochemical performances. Herein, nitrogen-doped mesoporous carbon spheres (MCS) are synthesized by a facile hard template method. The MCS demonstrate larger interlayer spacing in a short range, high specific surface area, abundant mesoporous structures and active sites, enhancing K-ion migration and diffusion. Furthermore, we screen out the pyrolysis temperature of 900 °C and the pore diameter of 7 nm as optimized conditions for MCS to improve performances. In detail, the optimized MCS-7-900 electrode achieves high rate capacity (107.9 mAh g−1 at 5000 mA g−1) and stably brings about 3600 cycles at 1000 mA g−1. According to electrochemical kinetic analysis, the capacitive-controlled effects play dominant roles in total storage mechanism. Additionally, the full-cell equipped MCS-7-900 as anode is successfully constructed to evaluate the practicality of MCS.

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Enhanced peroxymonosulfate activation process based on homogenously dispersed iron and nitrogen active sites on a three-dimensional porous carbon framework

Chemical Engineering Journal ◽

10.1016/j.cej.2020.126537 ◽

2021 ◽

Vol 404 ◽

pp. 126537

Author(s):

Likun Chen ◽

Yifei Huang ◽

Manli Zhou ◽

Kewen Xing ◽

Longjun Rao ◽

...

Keyword(s):

Porous Carbon ◽

Active Sites ◽

Three Dimensional ◽

Activation Process ◽

Carbon Framework

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An experimental and theoretical study of the adsorption of aromatics possessing electron-withdrawing and electron-donating functional groups by chemically modified activated carbons

Carbon ◽

10.1016/s0008-6223(97)00072-9 ◽

1997 ◽

Vol 35 (9) ◽

pp. 1339-1348 ◽

Cited By ~ 273

Author(s):

L.R. Radovic ◽

I.F. Silva ◽

J.I. Ume ◽

J.A. Menéndez ◽

C.A.Leon Y Leon ◽

...

Keyword(s):

Functional Groups ◽

Theoretical Study ◽

Activated Carbons ◽

Chemically Modified ◽

Modified Activated Carbons

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

Jurnal Teknologi ◽

10.11113/jt.v74.4876 ◽

2015 ◽

Vol 74 (11) ◽

Cited By ~ 5

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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Zero-Cost Agricultural Wastes as Sources for Activated Carbons Synthesis: Lead Ions Removal from Wastewaters

Proceedings ◽

10.3390/proceedings2110652 ◽

2018 ◽

Vol 2 (11) ◽

pp. 652 ◽

Cited By ~ 3

Author(s):

George Z. Kyzas ◽

Athanasios C. Mitropoulos

Keyword(s):

Activated Carbons ◽

Freundlich Isotherm ◽

Lead Ions ◽

Isotherm Models ◽

Activation Process ◽

Strong Impact ◽

Equilibrium Data ◽

Preparation Route ◽

Temperature Equilibrium ◽

Gibb’S Free Energy

In the present study, activated carbons (PAC) were hydrothermally prepared with an environmental friendly preparation route after pyrolysis from biomass (specifically from agricultural (potato) peels). The prepared biochars were activated with potassium hydroxide (chemical activities). The preparation route had a strong impact on the pore structure of PAC. In addition, surface chemistry was also affected by the preparation and activation process. The adsorbent materials were also characterized by Scanning Electron Microscopy. The prepared activated carbons were used as adsorbents for the removal of lead ions. Batch experiments were performed to investigate the effect of physico-chemical parameters, such as pH, contact time, initial metal concentration and temperature. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The thermodynamic parameters such as the change of enthalpy (ΔH0), entropy (ΔS0) and Gibb’s free energy (ΔG0) of adsorption systems were also determined and evaluated.

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