Micropore Size Distribution of Activated Carbon Fiber Using the Density Functional Theory and Other Methods

Langmuir ◽  
2000 ◽  
Vol 16 (9) ◽  
pp. 4300-4304 ◽  
Author(s):  
Mustapha El-Merraoui ◽  
Masayuki Aoshima ◽  
Katsumi Kaneko
Keyword(s):  
Density Functional Theory ◽  
Activated Carbon ◽  
Carbon Fiber ◽  
Size Distribution ◽  
Density Functional ◽  
Activated Carbon Fiber ◽  
Functional Theory ◽  
Micropore Size Distribution ◽  
The Density Functional Theory ◽  
Micropore Size

scholarly journals Multimodels computation for adsorption capacity of activated carbon

2017 ◽  
Vol 36 (1-2) ◽  
pp. 508-520 ◽  
Author(s):  
Guodong Wang ◽  
Yun Tian ◽  
Jianchun Jiang ◽  
Jianzhong Wu
Keyword(s):  
Density Functional Theory ◽  
Activated Carbon ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Density Functional ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Functional Theory

The pore size distribution of activated carbon is conventionally characterized with nitrogen adsorption measurements at 77 K. The adsorption isotherms are commonly analyzed with a nonlocal density functional theory in combination with a mathematical model for the pore size and geometry. While nonlocal density functional theory is significantly more accurate than the Brunauer–Emmett–Teller theory for gas adsorption, its application to materials characterization is mostly based on a mean-field approximation for van der Waals attractions that is only qualitative in comparison with alternative versions of nonlocal density functional theory or molecular simulations. Toward development of a more reliable theoretical procedure, we compare mean-field approximation-nonlocal density functional theory with three recent versions of non-mean-field methods for gas adsorption at conditions corresponding to experiments for porous materials characterization. The potential applicability of different nonlocal density functional theory methods for pore size distribution predictions is evaluated in terms of the theoretical error bound scale analysis. We find that the weight density approximation is the most reliable for predicting the pore size distribution of amorphous porous materials. In addition to accurate isotherm, weight density approximation yields the theoretical error bound scale for pore size distribution prediction nearly 104 times narrower than that corresponding to mean-field approximation. The new theoretical procedure has been used to analyze the pore size distribution of four activated carbon samples and to predict the adsorption capacities of these materials.

scholarly journals Experimental and Density Functional Theory (DFT): a Dual Approach for the Adsorption of Cd (II) Ion from Aqueous Solution by Starch-Based Activated Carbon

2021 ◽  
Author(s):  
Saad Melhi ◽  
Saeed Ullah Jan ◽  
Adnan Ali Khan ◽  
Khan Badshah ◽  
Saeed Ullah ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Activated Carbon ◽  
Industrial Wastewater ◽  
Active Sites ◽  
Density Functional ◽  
Functional Theory ◽  
Dual Approach ◽  
The Density Functional Theory ◽  
Synthetic Solution ◽  
Ft Ir

Cadmium (II) contamination in the environment is an emerging problem due to its acute toxicity and mobility, so it is very urgent to remove this species from industrial wastewater before it is discharged into the environment. Thus, a starch-based activated carbon (AC) with a specific surface area of 1600 m2g-1 is used as an adsorbent for the capturing of toxic Cadmium (II) ions from synthetic solution. The sorbent is characterized by BET, SEM, TEM, XRD, FT-IR, TGA, and zeta potential. The maximum uptake (284 mg g-1) of Cadmium (II) ion is obtained at pH 6. The thermodynamics parameters like ∆G, ∆H, ΔS are found to be -17.42 kJmol-1, 6.49 kJ mol-1, and 55.66 Jmol-1K-1 respectively, revealing that the adsorption mechanism is endothermic, spontaneous, and feasible. The experimental data follows the D-R and Langmuir models well. The mass transfer is controlled by pseudo 2nd order kinetics. Furthermore, the density functional theory simulations demonstrate that the activated carbon strongly interacted with the Cd (II) ion through its various active sites. The adsorption energy noted for all interactive sites is highly negative (-0.45 eV to -10.03 eV), which shows that the adsorption process is spontaneous and stable which is in agreement with the experimental thermodynamics analysis.

scholarly journals Electron-phonon interaction in In-induced √7 ×√3 structures on Si(111) from first-principles

2021 ◽  
Author(s):  
I. Yu. Sklyadneva ◽  
Rolf Heid ◽  
Pedro Miguel Echenique ◽  
Evgueni Chulkov
Keyword(s):  
Density Functional Theory ◽  
Double Layer ◽  
First Principles ◽  
Linear Response ◽  
Density Functional ◽  
Single Layer ◽  
Phonon Interaction ◽  
Functional Theory ◽  
Electron Phonon Interaction ◽  
The Density Functional Theory

Electron-phonon interaction in the Si(111)-supported rectangular √(7 ) ×√3 phases of In is investigated within the density-functional theory and linear-response. For both single-layer and double-layer √(7 ) ×√3 structures, it...

scholarly journals Study on the interaction between catechin and cholesterol by the density functional theory

2020 ◽  
Vol 18 (1) ◽  
pp. 357-368
Author(s):  
Kaiwen Zheng ◽  
Kai Guo ◽  
Jing Xu ◽  
Wei Liu ◽  
Junlang Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Charge Transfer ◽  
Density Functional ◽  
Antioxidant Properties ◽  
Micelle Formation ◽  
Aromatic Rings ◽  
Hydrogen Bond Interaction ◽  
Functional Theory ◽  
The Density Functional Theory

AbstractCatechin – a natural polyphenol substance – has excellent antioxidant properties for the treatment of diseases, especially for cholesterol lowering. Catechin can reduce cholesterol content in micelles by forming insoluble precipitation with cholesterol, thereby reducing the absorption of cholesterol in the intestine. In this study, to better understand the molecular mechanism of catechin and cholesterol, we studied the interaction between typical catechins and cholesterol by the density functional theory. Results show that the adsorption energies between the four catechins and cholesterol are obviously stronger than that of cholesterol themselves, indicating that catechin has an advantage in reducing cholesterol micelle formation. Moreover, it is found that the molecular interactions of the complexes are mainly due to charge transfer of the aromatic rings of the catechins as well as the hydrogen bond interactions. Unlike the intuitive understanding of a complex formed by hydrogen bond interaction, which is positively correlated with the number of hydrogen bonds, the most stable complexes (epicatechin–cholesterol or epigallocatechin–cholesterol) have only one but stronger hydrogen bond, due to charge transfer of the aromatic rings of catechins.

A trinuclear chromium(III) chlorocarbyne

2021 ◽  
Author(s):  
Takashi Kurogi ◽  
Keiichi Irifune ◽  
Takahiro Enoki ◽  
Kazuhiko Takai
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Terminal Alkynes ◽  
Functional Theory ◽  
The Density Functional Theory

Reduction of CCl4 by CrCl2 in THF afforded a trinuclear chromium(III) carbyne [CrCl(thf)2)]3(μ3-CCl)(μ-Cl)3. The chlorocarbyne complex reacted with aldehydes to afford chloroallylic alcohols and terminal alkynes. The density functional theory...

Boron nitride zigzag nanoribbons: optimal thermoelectric systems

2015 ◽  
Vol 17 (34) ◽  
pp. 22448-22454 ◽  
Author(s):  
K. Zberecki ◽  
R. Swirkowicz ◽  
J. Barnaś
Keyword(s):  
Density Functional Theory ◽  
Boron Nitride ◽  
Density Functional ◽  
Thermoelectric Effects ◽  
Functional Theory ◽  
Thermoelectric Systems ◽  
The Density Functional Theory ◽  
Boron Nitride Nanoribbons

Conventional and spin related thermoelectric effects in zigzag boron nitride nanoribbons are studied theoretically within the Density Functional Theory (DFT) approach.

Sign in / Sign up

Export Citation Format

Share Document