scholarly journals KOH activation of coal-derived microporous carbons for oxygen reduction and supercapacitors

RSC Advances ◽  
2020 ◽  
Vol 10 (27) ◽  
pp. 15707-15714 ◽  
Author(s):  
Shaokui Guo ◽  
Beibei Guo ◽  
Ruguang Ma ◽  
Yufang Zhu ◽  
Jiacheng Wang
Keyword(s):  
Specific Surface ◽  
Oxygen Reduction ◽  
Electrode Materials ◽  
Koh Activation ◽  
Porous Carbons ◽  
Microporous Carbons ◽  
Surface Areas ◽  
Specific Surface Areas ◽  
Natural Coal

Porous carbons (PCs) with high specific surface areas were prepared using natural coal as precursor coupled with KOH activation, showing great potential as electrode materials for oxygen reduction and supercapacitors.

scholarly journals Combined effect of nitrogen-doped functional groups and porosity of porous carbons on electrochemical performance of supercapacitors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Ilnicka ◽  
Malgorzata Skorupska ◽  
Mariusz Szkoda ◽  
Zuzanna Zarach ◽  
Piotr Kamedulski ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Specific Surface ◽  
Functional Groups ◽  
Electrode Materials ◽  
Electrochemical Behaviour ◽  
Porous Carbons ◽  
Nitrogen Doped ◽  
Surface Areas ◽  
Area Functional ◽  
Nitrogen Contents

AbstractIn this work, nitrogen-doped porous carbons obtained from chitosan, gelatine, and green algae were investigated in their role as supercapacitor electrodes. The effects of three factors on electrochemical performance have been studied—of the specific surface area, functional groups, and a porous structure. Varying nitrogen contents (from 5.46 to 10.08 wt.%) and specific surface areas (from 532 to 1095 m2 g−1) were obtained by modifying the carbon precursor and the carbonization temperature. Doping nitrogen into carbon at a level of 5.74–7.09 wt.% appears to be the optimum for obtaining high electrochemical capacitance. The obtained carbons exhibited high capacitance (231 F g−1 at 0.1 A g−1) and cycle durability in a 0.2 mol L−1 K2SO4 electrolyte. Capacitance retention was equal to 91% at 5 A g−1 after 10,000 chronopotentiometry cycles. An analysis of electrochemical behaviour reveals the influence that nitrogen functional groups have on pseudocapacitance. While quaternary-N and pyrrolic-N nitrogen groups have an enhancing effect, due to the presence of a positive charge and thus improved electron transfer at high current loads, the most important functional group affecting energy storage performance is graphite-N/quaternary-N. The study points out that the search for the most favourable organic precursors is as important as the process of converting precursors to carbon-based electrode materials.

Biomass based nitrogen-doped structure-tunable versatile porous carbon materials

2017 ◽  
Vol 5 (25) ◽  
pp. 12958-12968 ◽  
Author(s):  
Xin Zhou ◽  
Penglei Wang ◽  
Yagang Zhang ◽  
Lulu Wang ◽  
Letao Zhang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Porous Carbon ◽  
Carbon Materials ◽  
Porous Carbons ◽  
One Pot ◽  
Nitrogen Doped ◽  
Porous Carbon Materials ◽  
Surface Areas ◽  
Cellulose Carbamate ◽  
Specific Surface Areas

Hierarchical nitrogen-doped porous carbons (HNPCs) with tunable pore structures and ultrahigh specific surface areas were designed and prepared from sustainable biomass precursor cellulose carbamate via simultaneous carbonization and activation by a facile one-pot approach.

N-doped carbon nanocages with high catalytic activity and durability for oxygen reduction

2015 ◽  
Vol 3 (23) ◽  
pp. 12427-12435 ◽  
Author(s):  
Xiao Xia Wang ◽  
Biao Zou ◽  
Xin Xin Du ◽  
Jian Nong Wang
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction Reaction ◽  
Specific Surface ◽  
Oxygen Reduction ◽  
Reduction Reaction ◽  
High Catalytic Activity ◽  
Surface Areas ◽  
Excellent Activity ◽  
Specific Surface Areas

N-doped carbon nanocages with high specific surface areas exhibited excellent activity and durability for oxygen reduction reaction in acidic electrolytes.

Pure and strontium carbonate nanoparticles functionalized microporous carbons with high specific surface areas derived from chitosan for CO2 adsorption

2019 ◽  
Vol 2 (3) ◽  
pp. 337-349 ◽  
Author(s):  
Gurwinder Singh ◽  
Steffi Tiburcius ◽  
Sujanya Maria Ruban ◽  
Dhanush Shanbhag ◽  
C. I. Sathish ◽  
...  
Keyword(s):  
Specific Surface ◽  
Co2 Adsorption ◽  
Strontium Carbonate ◽  
Microporous Carbons ◽  
Surface Areas ◽  
Specific Surface Areas

scholarly journals Effect of Hydrophilicity of Activated Carbon Electrodes on Desalination Performance in Membrane Capacitive Deionization

2019 ◽  
Vol 9 (23) ◽  
pp. 5055 ◽  
Author(s):  
Kyusik Jo ◽  
Youngbin Baek ◽  
Changha Lee ◽  
Jeyong Yoon
Keyword(s):  
Activated Carbon ◽  
Ion Exchange ◽  
Surface Chemistry ◽  
Specific Surface ◽  
Electrode Materials ◽  
Carbon Electrodes ◽  
Water Molecules ◽  
Capacitive Deionization ◽  
Surface Areas ◽  
Specific Surface Areas

Membrane capacitive deionization (MCDI) is a modification of capacitive deionization (CDI) using ion-exchange membranes (IEM) in front of the electrodes. Electrode properties, especially the specific surface area, are known to be strongly related with desalination performance in CDI, but the effects of other properties in MCDI are not fully understood. The objective of this study was to investigate the effect of hydrophilicity in activated carbon electrodes on desalination performance in MCDI. Two types of activated carbon (P60 and YS-2) whose specific surface areas were similar were used as electrode materials, but they had different hydrophilicity (i.e., P60 was originally hydrophobic and YS-2 was relatively hydrophilic due to its nitrogen-containing surface chemistry). These hydrophilic electrodes (either the electrode itself or modified with polydopamine (PDA)) led to an increase in the salt adsorption capacity (SAC) in MCDI because they facilitated the access of both ions and water molecules into the electrode pores. In particular, the SAC of the P60 electrode displayed a large increase to almost reach that of the YS-2 electrode due to the improved hydrophilicity with PDA modification and the insignificant effects of PDA modification on an already hydrophilic YS-2 electrode. Additionally, PDA-modified IEM in MCDI reduced the SAC as a result of the additional insulating PDA layer with little changes in hydrophilicity.

scholarly journals Ultrafine porous boron nitride nanofibers synthesized via a freeze-drying and pyrolysis process and their adsorption properties

RSC Advances ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 1253-1259 ◽  
Author(s):  
Jing Lin ◽  
Lulu Xu ◽  
Yang Huang ◽  
Jie Li ◽  
Weijia Wang ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Specific Surface ◽  
Freeze Drying ◽  
Adsorption Properties ◽  
Pyrolysis Process ◽  
Surface Areas ◽  
Aspect Ratios ◽  
Large Pore ◽  
Specific Surface Areas

Ultrafine porous boron nitride nanofibers with high aspect ratios, high specific surface areas and large pore volumes has been synthesized in large quantity via a freeze-drying and post pyrolysis process.

scholarly journals Experimental Investigation of Coal Dust Wettability Based on Surface Contact Angle

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Gang Zhou ◽  
Han Qiu ◽  
Qi Zhang ◽  
Mao Xu ◽  
Jiayuan Wang ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Specific Surface ◽  
Coal Dust ◽  
Single Point ◽  
Contact Angles ◽  
Critical Surface ◽  
Volume Percentage ◽  
Surface Areas ◽  
Specific Surface Areas

Wettability is one of the key chemical properties of coal dust, which is very important to dedusting. In this paper, the theory of liquid wetting solid was presented firstly; then, taking the gas coal of Xinglongzhuang coal mine in China as an example, by determination of critical surface tension of coal piece, it can be concluded that only when the surface tension of surfactant solution is less than 45 mN/m can the coal sample be fully wetted. Due to the effect of particle dispersity, compared with the contact angle of milled coal particle, not all the contact angles of screened coal powder with different sizes have a tendency to increase. Furthermore, by the experiments of coal samples’ specific surface areas and porosities, it can be achieved that the volume of single-point total pore decreases with the gradual decreasing of coal’s porosity, while the ultramicropores’ dispersities and multipoint BET specific surface areas increase. Besides, by a series of contact angle experiments with different surfactants, it can be found that with the increasing of porosity and the decreasing of volume percentage of ultramicropore, the contact angle tends to reduce gradually and the coal dust is much easier to get wetted.

Facile Method To Synthesize Mesoporous Multimetal Oxides (ATiO3, A = Sr, Ba) with Large Specific Surface Areas and Crystalline Pore walls

2010 ◽  
Vol 22 (4) ◽  
pp. 1276-1278 ◽  
Author(s):  
Xiaoxing Fan ◽  
Ying Wang ◽  
Xinyi Chen ◽  
Ling Gao ◽  
Wenjun Luo ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Areas ◽  
Specific Surface Areas
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