scholarly journals Activated graphene as a material for supercapacitor electrodes: effects of surface area, pore size distribution and hydrophilicity

2019 ◽  
Vol 21 (32) ◽  
pp. 17901-17912 ◽  
Author(s):  
Artem Iakunkov ◽  
Vasyl Skrypnychuk ◽  
Andreas Nordenström ◽  
Elizaveta A. Shilayeva ◽  
Mikhail Korobov ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
Pore Volume ◽  
Bet Surface Area ◽  
Oxide Materials ◽  
Reduced Graphene

Activated reduced graphene oxide materials (a-rGO) with variation of N2 BET surface area 1000–3000 m2 g−1 were tested in supercapacitors. Correlations between electrode performance and pore size, pore volume, N2 and H2O BET surface area were evaluated.

The relationship between geotechnical index properties and the pore-size distribution of compacted clayey silts

2015 ◽  
Vol 22 (6) ◽  
Author(s):  
Nazile Ural
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Correlation Coefficients ◽  
Liquid Limit ◽  
Index Properties

AbstractIn this study, the relationships between geotechnical index properties and the pore-size distribution of compacted natural silt and artificial soil mixtures, namely, silt with two different clays and three different clay percentages (10%, 20%, and 40%), were examined and compared. Atterberg’s limit tests, standard compaction tests, mercury intrusion porosimetry, X-ray diffraction, scanning electron microscopy (SEM) analysis, and Brunauer-Emmett-Teller specific surface analysis were conducted. The results show that the liquid limit, the cumulative pore volume, and specific surface area of artificially mixed soils increase with an increase in the percentage of clay. The cumulative pore volume and specific surface area with geotechnical index properties were compared. High correlation coefficients were observed between the specific areas and both the liquid limit and the plasticity index, as well as between the cumulative pore volume and both the clay percentage and the

scholarly journals Novel Activated Carbon Nanofibers Composited with Cost-Effective Graphene-Based Materials for Enhanced Adsorption Performance toward Methane

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2064
Author(s):  
Faten Ermala Che Othman ◽  
Norhaniza Yusof ◽  
Noorfidza Yub Harun ◽  
Muhammad Roil Bilad ◽  
Juhana Jaafar ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Activated Carbon ◽  
Specific Surface ◽  
Pore Size ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
Carbon Nanofibers ◽  
Specific Surface Area ◽  
Activated Carbon Nanofibers ◽  
Reduced Graphene

Various types of activated carbon nanofibers’ (ACNFs) composites have been extensively studied and reported recently due to their extraordinary properties and applications. This study reports the fabrication and assessments of ACNFs incorporated with graphene-based materials, known as gACNFs, via simple electrospinning and subsequent physical activation process. TGA analysis proved graphene-derived rice husk ashes (GRHA)/ACNFs possess twice the carbon yield and thermally stable properties compared to other samples. Raman spectra, XRD, and FTIR analyses explained the chemical structures in all resultant gACNFs samples. The SEM and EDX results revealed the average fiber diameters of the gACNFs, ranging from 250 to 400 nm, and the successful incorporation of both GRHA and reduced graphene oxide (rGO) into the ACNFs’ structures. The results revealed that ACNFs incorporated with GRHA possesses the highest specific surface area (SSA), of 384 m2/g, with high micropore volume, of 0.1580 cm3/g, which is up to 88% of the total pore volume. The GRHA/ACNF was found to be a better adsorbent for CH4 compared to pristine ACNFs and reduced graphene oxide (rGO/ACNF) as it showed sorption up to 66.40 mmol/g at 25 °C and 12 bar. The sorption capacity of the GRHA/ACNF was impressively higher than earlier reported studies on ACNFs and ACNF composites. Interestingly, the CH4 adsorption of all ACNF samples obeyed the pseudo-second-order kinetic model at low pressure (4 bar), indicating the chemisorption behaviors. However, it obeyed the pseudo-first order at higher pressures (8 and 12 bar), indicating the physisorption behaviors. These results correspond to the textural properties that describe that the high adsorption capacity of CH4 at high pressure is mainly dependent upon the specific surface area (SSA), pore size distribution, and the suitable range of pore size.

Rh/Ni wet-impregnated Ia3d mesostructured aluminosilicate and r-GO catalysts for hydrodeoxygenation of phenoxybenzene

2017 ◽  
Vol 41 (16) ◽  
pp. 7893-7907 ◽  
Author(s):  
Sudhakar Pichaikaran ◽  
Arumugam Pandurangan
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
Structural Properties ◽  
Bet Surface Area ◽  
Xps Analysis ◽  
Icp Oes ◽  
Reduced Graphene ◽  
Ft Ir

Rh/Ni bimetallic supported bifunctional 3D porous aluminosilicate and Rh/Ni supported reduced graphene oxide (r-GO) catalysts were synthesised and their structural properties evaluated by XRD, BET-surface area, FT-IR, NH3-TPD, H2-TPR, ICP-OES, HRTEM-EDAX and XPS analysis.

Preparation of Mesoporous Alumina Using Hexamethyl Disilylamine as Substitute Solvent

2013 ◽  
Vol 773 ◽  
pp. 482-486 ◽  
Author(s):  
Su Min Cui ◽  
Li Li Ren ◽  
Feng Chao Cao
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Supercritical Drying ◽  
Mesoporous Alumina ◽  
Bet Surface Area ◽  
High Porosity ◽  
Drying Method

Mesoporous inorganic alumina with framework walls has been synthesized using a new and simple non-supercritical drying method. As a substitute solvent, hexamethyl disilylamine (HMDS) plays a definitive part for synthesis of the mesoporous alumina due to its special characters. The resulting alumina product shows high BET surface area, concentrated distribution of diameter and high porosity. The pore size distribution of alumina we prepared is concentrated around 11nm. Its structure still maintained stable and the BET surface area could reach up to 413.4593m2/g after being calcined at 800°C.

Effect of heating and acid pre-treatment on pore size distribution of sepiolite

Clay Minerals ◽  
1999 ◽  
Vol 34 (4) ◽  
pp. 647-655 ◽  
Author(s):  
S. Balci
Keyword(s):  
Thermal Treatment ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Elevated Temperatures ◽  
Total Porosity ◽  
Micropore Volume ◽  
Industrial Applications ◽  
Bet Surface Area

AbstractDue to its channels of molecular dimensions and a high specific surface area, sepiolite has many industrial applications which require high resistance to thermal effects in addition to a large surface area. On heating, sorbed water molecules are removed causing changes in the pore size distribution. In this study, the effects of thermal treatment on the pore structure of sepiolite and the acid-treated sepiolite samples were investigated. The solid density of sepiolite, measured by a He displacement technique, was 2.08 g cm-3 and total porosity was ~0.58. Both of these values showed an increase at 100°C, then decreased with further temperature increase due to crystal deformation and channel plugging which occurred at elevated temperatures. The BET surface area of the original sepiolite was 148 m2 g-1, and increased to 263 m2 g-1 at 100°C and then started to decrease. Approximately 16% of the total volume was in the micropores at 100°C. The acid pre-activation caused restrictions in possible crystal deformation during thermal treatment. The micropore volume increased to 20% and BET surface area reached values >500 m2 g-1 for the acid-treated samples.

Synthesis and Characterization of Dense Mesoporous Alumina

2014 ◽  
Vol 616 ◽  
pp. 252-257
Author(s):  
Atsushi Nakahira ◽  
Hironobu Nishimoto ◽  
Yukitaka Hamada ◽  
Yuki Yamasaki
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
High Specific Surface Area ◽  
Mesoporous Alumina ◽  
Bet Surface Area ◽  
Synthesis And Characterization ◽  
Narrow Pore Size Distribution

Dense mesoporous alumina bulks were successfully synthesized by a hydrothermal hot-pressing (HHP) method for mesoporous alumina powders prepared as starting material with a high BET surface area and narrow pore size distribution. As a result, mesoporous alumina HHP bulks had high density with uniformity pore size distribution and a high specific surface area. Their microstructural features for dense mesoporous alumina bulks were observed by SEM. The characterization of mesopores was examined.

Macroporous 4-Vinylpyridine-divinylbenzene – Estimation of Pore Volume, Surface Area, and Pore Size Distribution

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Muhammad Arif Malik
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Pore Volume ◽  
Good Accuracy ◽  
Suspension Polymerization ◽  
Phthalate Esters ◽  
Measuring Cylinder ◽  
Swelling Coefficient

Abstract4-Vinylpyridine-divinylbenzene copolymer beads of ~0.3 mm in diameter were synthesized by suspension polymerization technique. The beads were made porous by dilution of the monomers with phthalate esters. The porosity was varied by changing the diluent, by varying the degree of dilution, and by varying the ratio of divinylbenzene in the monomers. Pore volume, surface area, and pore size distribution were determined by mercury penetration method, and densities of the dried copolymers were determined by a measuring cylinder and a balance. Statistical analysis of the data shows that the surface area and swelling coefficient in acetone can be estimated from the pore volume value with a reasonable good accuracy. Pore size distribution curves for the copolymers having pore volume in the range of 0.1 ml/g to 0.8 ml/g are shown. One can approximately estimate the pore size distribution if the pore volume is known. The pore volume can be estimated with a reasonable good accuracy from the density of the copolymers.

The Effect of Surface Area, Pore Volume, and Pore Size Distribution on the Modified Multiwalled Carbon Nanotubes

2014 ◽  
Vol 625 ◽  
pp. 148-151 ◽  
Author(s):  
Rahmam Syuhaidah ◽  
Muti Mohamed Norani ◽  
Suriati Sufian
Keyword(s):  
Carbon Nanotubes ◽  
Surface Treatment ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Multiwalled Carbon Nanotubes ◽  
Pore Volume ◽  
Multiwalled Carbon ◽  
Effect Of Surface

Carbon Nanotubes (CNT) have emerged and gained great interest for research in many applications because of their unique specific characteristics such as having high porosity, high surface area and the existence of a wide spectrum of surface functional groups through chemical modification. Multiwalled carbon nanotubes (MWCNT) is a type of CNT that comprises of multiple layers of concentric cylinders. The overall study of this research work is to modify MWCNT to become a good adsorbent that can adsorb CO2 at its optimum capacity. In order to make MWCNT as an efficient adsorbent, surface treatment on pristine MWCNT is necessary to overcome the hydrophobicity issue by the introduction of carboxyl group. Upon the surface treatment, functionalization of MWCNT with 3-Aminopropyl triethoxysilane (APTS) was conducted to obtain the attachment of amine group that will assist MWCNT in adsorbing CO2. The surface treatment and functionalization process undergone by MWCNT changed the physical properties of MWCNT such as the surface area, pore volume, and pore size distribution. These properties can be determined using surface area and pore analyzer (SAP). Sample that treated with the mixture of nitric and sulfuric acid (HNO3/H2SO4) and functionalized with APTS gives the lowest surface area (22.07 m2/g) and pore volume (0.06 cm3/g). The pore size distribution also decreases due to the most presence of functional group onto the surface of modified MWCNT. This research paper is focusing on the effect of surface area, pore volume, and pore size distribution on the modified MWCNT.

scholarly journals Tuning Porosity of Reduced Graphene Oxide Membrane Materials by Alkali Activation

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2093
Author(s):  
Yang Shen ◽  
Luca Maurizi ◽  
Giuliana Magnacca ◽  
Vittorio Boffa ◽  
Yuanzheng Yue
Keyword(s):  
Graphene Oxide ◽  
Specific Surface ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Potassium Hydroxide ◽  
Alkali Activation ◽  
Gravimetric Analysis ◽  
Reduced Graphene

The alkali-activation method allows for obtaining highly porous carbon materials. In this study, we explored the effect of activation temperature and potassium hydroxide concentration on the pore structure of reduced graphene oxide (rGO), as potential membrane material. Above 700 °C, potassium species react with the carbon plane of rGO to form nanopores. This activation process is deeply studied through DSC measurements and isothermal gravimetric analysis. The porosity of the formed materials consists of both micro- and mesopores, with most of the pores having a size smaller than 10 nm. The specific surface area and pore volume increase with increasing the potassium hydroxide/graphene oxide weight ratio (KOH/GO) up to 7 (897 m2∙g−1 and 0.97 cm3∙g−1, respectively). However, for a synthesis mixture with KOH/GO of 10, the specific surface area of the produced material drops to 255 m2∙g−1. The film-forming ability of the porous reduced graphene oxide (PRGO) was tested by drop-casting on porous silicon carbide substrates. In this case, continuous PRGO films were obtained only from dispersions with 5 g∙L−1 GO loading and KOH/GO ≤3. Such films can still have high specific surface area and pore volume (up to 528 m2∙g−1 and 0.53 cm3∙g−1) and main pore volume <10 nm. Hence, they can potentially be applied as membrane devices, but their scalability and their adhesion on the substrate under realistic filtration conditions still remain challenges.

Are you using the right probe molecules for assessing the textural properties of metal–organic frameworks?

2022 ◽  
Author(s):  
Timur Islamoglu ◽  
Karam B. Idrees ◽  
Florencia A. Son ◽  
Zhijie Chen ◽  
Seung-Joon Lee ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Porous Materials ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Pore Volume ◽  
Metal Organic Frameworks ◽  
Textural Properties ◽  
Metal Organic ◽  
The Right

Textural properties—such as the surface area, pore size distribution, and pore volume—are at the forefront of characterization for porous materials.

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