scholarly journals Acacia auriculiformis–Derived Bimodal Porous Nanocarbons via Self-Activation for High-Performance Supercapacitors

2021 ◽  
Vol 9 ◽  
Author(s):  
Vinay S. Bhat ◽  
Titilope John Jayeoye ◽  
Thitima Rujiralai ◽  
Uraiwan Sirimahachai ◽  
Kwok Feng Chong ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Nanomaterials ◽  
Carbon Materials ◽  
Active Material ◽  
Activation Mechanism ◽  
Acacia Auriculiformis ◽  
Symmetric Supercapacitor ◽  
Hierarchical Porous

Carbon nanomaterials derived from Acacia auriculiformis pods as electrodes for the electrochemical double-layer capacitors were explored. Four pyrolysis temperatures were set (400, 600, 800, and 1,000°C) to understand the role of temperature in biomass pyrolysis via a possible “self-activation” mechanism for the synthesis of carbon materials. The carbon materials synthesized at 800°C (AAC800) were found to exhibit a well-organized hierarchical porous structure, quantified further from N2 adsorption/desorption isotherms with a maximum specific surface area of 736.6 m2/g. Micropores were found to be contributing toward enhancing the specific surface area. AAC800 exhibited a maximum specific capacitance of 176.7 F/g at 0.5 A/g in 6.0 M KOH electrolyte in a three-electrode setup. A symmetric supercapacitor was fabricated using AAC800 as an active material in an organic electrolyte composed of 1.0 M tetraethylammonium tetrafluoroborate (TEABF4) as a conducting salt in the acetonitrile (ACN) solvent. The self-discharge of the cell/device was analyzed from fitting two different mathematical models; the cell also exhibited a remarkable coulombic efficiency of 100% over 10,000 charge/discharge cycles, retaining ∼93% capacitance at 2.3 V.

scholarly journals Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Hierarchical Porous

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.

Carbon nanomaterials based on interpolyelectrolyte complex lignosulfonate-chitosan

Holzforschung ◽  
2019 ◽  
Vol 73 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Olga Brovko ◽  
Irina Palamarchuk ◽  
Konstantin Bogolitsyn ◽  
Nikolay Bogdanovich ◽  
Artem Ivakhnov ◽  
...  
Keyword(s):  
Specific Surface ◽  
Nitrogen Content ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Nanomaterials ◽  
Electron Pair ◽  
Spherical Geometry ◽  
Processing Conditions ◽  
Interpolyelectrolyte Complex ◽  
New Approach

AbstractA new approach to the formation of “fullerene-like” carbon-nitrogen carbogels based on the interpolyelectrolyte complex lignosulfonate-chitosan (IPEC LSNa-CT) was developed. It was established that carbogel maintained the morphology of the precursor complex, i.e. the spherical geometry and the particle size of its main fractions (40–55 nm) were stored in the carbonizate. The influence of pyrolysis (Py) temperature was studied in the range of 500–1000°C on the structure of carbonizate. Carbogels obtained under different processing conditions have a well-developed microporous structure. The specific surface area of carbogels reduced with increasing Py temperature according to their nitrogen content. The maximum specific surface area (438.3 m2g−1) corresponds to the carbogel obtained at 600°C, while the maximum nitrogen content of this sample is 4.4%. The internal porosity of the material and the volume of supermicropores are reduced with increasing Py temperature due to the accumulation of double and triple carbon bonds in the carbogel. Apparently, the structure-forming N-atoms participate in the formation of condensed nitrogen-containing and cyclic structures as a donor of the electron pair and as such they accelerate the carbonization process.

Increase the Microporosity and CO2 Adsorption of a Commercial Activated Carbon

2015 ◽  
Vol 749 ◽  
pp. 17-21 ◽  
Author(s):  
Joanna Sreńscek Nazzal ◽  
Karolina Glonek ◽  
Jacek Młodzik ◽  
Urszula Narkiewicz ◽  
Antoni W. Morawski ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Materials ◽  
Micropore Volume ◽  
Microporous Carbon ◽  
Microporous Carbons ◽  
Adsorption Capacities

Microporous carbons prepared from commercial activated carbon WG12 by KOH and/or ZnCl2 treatment were examined as adsorbents for CO2 capture. The micropore volume and specific surface area of the resulting carbons varied from 0.52 cm3/g (1374 m2/g) to 0.70 cm3/g (1800 m2/g), respectively. The obtained microporous carbon materials showed high CO2 adsorption capacities at 40 bar pressure reaching 16.4 mmol/g.

Preparation of Fe/N co-doped hierarchical porous carbon nanosheets derived from chitosan nanofibers for high-performance supercapacitors

2021 ◽  
pp. 1-16
Author(s):  
Yaqi Yang ◽  
Ziqiang Shao ◽  
Feijun Wang
Keyword(s):  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Double Layer ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Active Sites ◽  
Transport Pathway ◽  
Carbon Nanosheets ◽  
Hierarchical Porous

Abstract Due to the low specific capacitance and small specific surface area of conventional carbon materials used as electrode materials for double-layer capacitors, the search for more ideal materials and ingenious preparation methods remains a major challenge. In this study, fractional porous carbon nanosheets were prepared by co-doping Fe and N with chitosan as nitrogen source. The advantage of this method is that the carbon nanosheets can have a large number of pore structures and produce a large specific surface area. The presence of Fe catalyzes the graphitization of carbon in the carbon layer during carbonization process, and further increases the specific surface area of the electrode material. This structure provides an efficient ion and electron transport pathway, which enables more active sites to participate in the REDOX reaction, thus significantly enhancing the electrochemical performance of SCs. The specific surface area of CS-800 is up to 1587 m2 g−1. When the current density is 0.5 A g−1, the specific capacitance of CS-800 reaches 308.84 F g−1, and remains 84.61 % of the initial value after 10,000 cycles. The Coulomb efficiency of CS-800 is almost 100 % after a long cycle, which indicates that CS-800 has more ideal double-layer capacitance and pseudo capacitance.

What are the practical limits for the specific surface area and capacitance of bulk sp2 carbon materials?

2015 ◽  
Vol 59 (2) ◽  
pp. 225-230 ◽  
Author(s):  
Yanhong Lu ◽  
Guankui Long ◽  
Long Zhang ◽  
Tengfei Zhang ◽  
Mingtao Zhang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Materials

Advances of Graphene for Adsorption of Dyes in Wastewater

2013 ◽  
Vol 804 ◽  
pp. 89-93
Author(s):  
Jing Yi Yang ◽  
Yu Qiong Chen ◽  
Ying Chuan Ma ◽  
Xin Zhang ◽  
Ling Ling Luo ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Materials ◽  
High Specific Surface Area ◽  
High Thermal Stability ◽  
Charge Carriers ◽  
Functionalized Graphene ◽  
Covalently Bonded ◽  
Mobility Of Charge Carriers

Graphene is a fascinating new member of carbon materials with honeycomb and one-atom-thick structure, consisting of 2D hexagonal lattices of sp2 carbon atoms covalently bonded. Graphene has a huge theory specific surface area (over 2600 m2 g1), good thermal conductivity, high values of Youngs modulus and fracture strength, high thermal stability and chemical stability and fast mobility of charge carriers, etc.. In recent years, many researchers found graphene have outstanding adsorption capacity of dyes in aqueous solution due to its high specific surface area. This paper summarized the graphene, graphene oxide and functionalized graphene removing various dyes in wastewater.

scholarly journals Ionothermally synthesized hierarchical porous Schiff-base-type polymeric networks with ultrahigh specific surface area for supercapacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (32) ◽  
pp. 19934-19939 ◽  
Author(s):  
Yuhang Zhao ◽  
Ping Liu ◽  
Xiaodong Zhuang ◽  
Dongqing Wu ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Schiff Base ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Synthesis Method ◽  
Ionothermal Synthesis ◽  
Polymeric Network ◽  
Polymeric Networks ◽  
Hierarchical Porous ◽  
One Step

A hierarchical porous polymeric network (HPPN) with ultrahigh specific surface area up to 2870 m2 g−1 was synthesized via a one-step ionothermal synthesis method without using templates.

3D hierarchical porous amidoxime fibers speed up uranium extraction from seawater

2019 ◽  
Vol 12 (6) ◽  
pp. 1979-1988 ◽  
Author(s):  
Xiao Xu ◽  
Hongjun Zhang ◽  
Junxuan Ao ◽  
Lu Xu ◽  
Xiyan Liu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Nuclear Fuel ◽  
Specific Surface Area ◽  
New Technology ◽  
High Specific Surface Area ◽  
Fuel Production ◽  
Uranium Extraction ◽  
Hierarchical Porous ◽  
Speed Up

The development of high specific surface area amidoxime-based polymeric (H-ABP) fibers presents a new technology for the synthesis of highly efficient adsorbents for uranium extraction from seawater (UES), thus opening a whole new means of nuclear fuel production from the ocean.

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