Hydrothermal Synthesis of MnO2-Loaded Porous Carbons for Supercapacitors

2016 ◽  
Vol 852 ◽  
pp. 870-875
Author(s):  
Zi Qiang Wang ◽  
Li Xian Sun ◽  
Fen Xu ◽  
Xiao Jun Peng
Keyword(s):  
Hydrothermal Synthesis ◽  
Phase Space ◽  
Hydrothermal Method ◽  
Tetragonal Phase ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Chemical Agent ◽  
Porous Carbons ◽  
Electrochemical Tests ◽  
Morphology And Structure

The porous carbons have been prepared by chemical activation using commercial activated carbons as precursors and KOH as the chemical agent, and the MnO2 and MnO2-loaded porous carbons have been synthesized via the hydrothermal method using the Mn (SO4)2·H2O and (NH4)2S2O8 as the reagents. The morphology and structure of the obtained materials are characterized by the SEM, XRD and N2 sorption. The obtained MnO2 exhibits rod-like morphology, which can be indexed to a pure tetragonal phase [space group: P42/mnm] of β-MnO2. The porous carbons and MnO2-loaded porous carbons show a well-developed porosity. The electrochemical tests indicate that the samples have excellent performances for the supercapacitors.

Fungi-derived hierarchically porous carbons for high-performance supercapacitors

RSC Advances ◽  
2015 ◽  
Vol 5 (6) ◽  
pp. 4396-4403 ◽  
Author(s):  
Jiacheng Wang ◽  
Qian Liu
Keyword(s):  
High Performance ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Organic Electrolyte ◽  
Carbon Precursor ◽  
Porous Carbons ◽  
Hierarchically Porous ◽  
Renewable Biomass ◽  
Supercapacitor Performance

Chemical activation of sustainable, renewable biomass fungi as the carbon precursor resulted in hierarchically porous activated carbons, demonstrating superior supercapacitor performance in organic electrolyte to commercially available carbons.

Low Temperature Synthesis of PbTiO3 Nanoparticles

2005 ◽  
Vol 475-479 ◽  
pp. 3517-3520
Author(s):  
Yu Jing Sun ◽  
Shi Tian ◽  
Xiao Bing Li
Keyword(s):  
Hydrothermal Synthesis ◽  
Low Temperature ◽  
Hydrothermal Method ◽  
Tetragonal Phase ◽  
Lead Acetate ◽  
Average Diameter ◽  
Effect Of Temperature ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis

PbTiO3 nano-sized powders were synthesized at 150oC by a new hydrothermal [denoted as sol-hydrothermal] method by using modified titanium tetra-n-butoxide and lead acetate as the precursors. Furthermore, tetragonal PbTi0.8O2.6 nano-sized powders were obtained by this method at 80oC. Compared with hydrothermal synthesis, the effect of temperature on the formation of products prepared by sol-hydrothermal was investigated. The characteristics of products were studied by XRD, TEM and SAXS. The results show sol-hydrothermal method choosing acetylacetonate-modified titanium tetra-n-butoxide and lead acetate to form a sol could obtain PbTiO3 in 120nm size and PbTi0.8O2.6 powders with average diameter of 30nm, and both of them are pure tetragonal phase. In addition, PbTi0.8O2.6 could be converted into PbTiO3 gradually after annealed at giving condition.

Preparation of Activated Carbon of Lignin from Straw Pulping by Chemical Activation Using Potassium Carbonate

2011 ◽  
Vol 704-705 ◽  
pp. 517-522 ◽  
Author(s):  
Xiao Juan Jin ◽  
Zhi Ming Yu ◽  
Gao Jiang Yan ◽  
Wu Yu
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Iodine Number ◽  
Surface Area ◽  
Potassium Carbonate ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Bet Surface Area ◽  
Chemical Agent ◽  
Optimum Conditions

Activated carbons were prepared through chemical activation of lignin from straw pulping precursor using potassium carbonate as the chemical agent. Effects of activated temperature, K2CO3/lignin ratio and the activated time on the yield, Iodine number of activated carbon were investigated. Experimental results indicated that the optimum conditions were as follow: activated temperature 800°C, K3CO3(40% concentration) /lignin ratio 5: l, activated time 50min. These conditions allowed us to obtain a BET surface area of 1104 m2/g, including the external or non-microporous surface of 417 m2/g，Amount of methylene blue adsorption, Iodine number and the yield of activated carbon prepared under optimum conditions were 10.6mL/0.lg,1310 mg/g and 19.75%, respectively.

Zirconium-promoted hydrothermal synthesis of hierarchical porous carbons with ordered cubic mesostructures under acidic aqueous conditions

RSC Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 4343-4353
Author(s):  
Anfeng Zhang ◽  
Keke Hou ◽  
Haiyang Duan ◽  
Wei Tan ◽  
Chunshan Song ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Hydrochloric Acid ◽  
Hydrothermal Method ◽  
Porous Carbons ◽  
Hierarchical Porous ◽  
Hierarchical Porous Carbons ◽  
Aqueous Conditions

Hierarchical porous carbons with ordered cubic mesostructure (Im3m) were synthesized under acidic aqueous conditions by a zirconium-promoted hydrothermal method, F127 as template, pre-synthesized resol as precursor, and hydrochloric acid as catalyst.

scholarly journals Chestnut-Derived Activated Carbon as a Prospective Material for Energy Storage

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4658 ◽  
Author(s):  
Katarzyna Januszewicz ◽  
Anita Cymann-Sachajdak ◽  
Paweł Kazimierski ◽  
Marek Klein ◽  
Justyna Łuczak ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Activated Carbons ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
Rate Capability ◽  
Activation Process ◽  
Porous Carbons ◽  
Subsequent Activation

In this work, we present the preparation and characterization of biomass-derived activated carbon (AC) in view of its application as electrode material for electrochemical capacitors. Porous carbons are prepared by pyrolysis of chestnut seeds and subsequent activation of the obtained biochar. We investigate here two activation methods, namely, physical by CO2 and chemical using KOH. Morphology, structure and specific surface area (SSA) of synthesized activated carbons are investigated by Brunauer-Emmett-Teller (BET) technique and scanning electron microscopy (SEM). Electrochemical studies show a clear dependence between the activation method (influencing porosity and SSA of AC) and electric capacitance values as well as rate capability of investigated electrodes. It is shown that well-developed porosity and high surface area, achieved by the chemical activation process, result in outstanding electrochemical performance of the chestnut-derived porous carbons.

scholarly journals Fast Microwave Synthesis of Hierarchical Porous Carbons from Waste Palm Boosted by Activated Carbons for Supercapacitors

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 405 ◽  
Author(s):  
Chaozheng Liu ◽  
Weimin Chen ◽  
Shu Hong ◽  
Mingzhu Pan ◽  
Min Jiang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Electrochemical Performances ◽  
Porous Carbons ◽  
Discharge Performance ◽  
Hierarchical Porous ◽  
Hierarchical Porous Carbons

The synthesis of biomass-derived porous carbons (PCs) for supercapacitors by conventional two-steps method (chemical activation after carbonization) is complicated and time-consuming. In this study, we present a one-step microwave activation strategy to prepare hierarchically PCs from waste palm boosted by activated carbons (ACs). ACs with various specific surface areas (14, 642, and 1344 m2·g−1) were used for the first time to fast absorb microwave energy for converting waste palm into hierarchically PCs, that is, PC1, PC2, and PC3, respectively. The morphological and structural characterizations of PCs were studied. Also, the electrochemical performances of supercapacitors based on PCs as electrodes were further investigated. The results showed that the PC (PC1) boosted by AC with the lowest specific surface area possessed a porous structure (containing micro-, meso-, and macro- pores) with the largest specific surface area (1573 m2·g−1) and the highest micropore volume (0.573 cm3·g−1), as well as the suitable mesoporosity (29.69%). The as-prepared PC1 supercapacitor even in a gel electrolyte (PVA/LiCl) exhibited a high specific capacitance of 226.0 F·g−1 at 0.5 A·g−1 and presented excellent charge-discharge performance with an energy density of 72.3 Wh·kg−1 at a power density of 1.4 kW·kg−1 and 50.0 Wh·kg−1 at 28.8 kW·kg−1. Moreover, this promising method exhibited a simple, rapid, and cost-effective preparation of carbon materials from renewable biomass for energy storage applications.

scholarly journals Preparation and Characterization of Activated Carbon from Poplar Sawdust by Chemical Activation: Comparison of Different Activating Agents and Carbonization Temperature

2018 ◽  
Vol 3 (11) ◽  
pp. 6-11 ◽  
Author(s):  
Funda Ateş ◽  
Öznur Özcan
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Experimental Studies ◽  
Carbonization Temperature ◽  
Bet Surface Area ◽  
Koh Activation ◽  
Chemical Agent ◽  
Poplar Sawdust

Activated carbons were prepared from poplar sawdust by chemical activation using ZnCl2, H3PO4 or KOH. The influence of activating agents, carbonization temperatures ranging from 500 ºC to 800 ºC, and mass ratio of chemical agent to precursor (1:1 and 2:1) on the porosity of activated carbons were studied. The properties of the carbons were characterized by adsorption/desorption of nitrogen to determine the BET areas, scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR). It was determined that the surface morphology and textural characteristics of activated carbons vary depending on the carbonization temperature or chemical agent. Maximum surface areas were obtained at carbonization temperatures of 500, 700 and 800 ºC for H3PO4, KOH and ZnCl2 activation, respectively. The activated carbons prepared using ZnCl2 and H3PO4 activation had a higher BET surface area (nearly 1100 m2/g) than that of the KOH activation (761 m2/g). This study also presents a comparison of mechanisms of activating agents and carbonization temperature. As a result of the experimental studies, positive results were obtained, and the production of activated carbon with a high surface area was conducted. 

Study of the temperature effect on the morphology and structure of ZnS nanoparticles synthesized by hydrothermal method

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3379-3388
Author(s):  
Claudia J. Bahena-Martínez ◽  
Nayely Torres-Gómez ◽  
Alfredo R. Vilchis-Néstor
Keyword(s):  
Hydrothermal Synthesis ◽  
Temperature Effect ◽  
Hydrothermal Method ◽  
Formation Mechanism ◽  
Zinc Sulphide ◽  
Effect Of Temperature ◽  
Zns Nanoparticles ◽  
Temperature Increment ◽  
Morphology And Structure ◽  
Subsequent Decomposition

AbstractThe control over the materials structure is crucial for the modulation of its properties, in order to achieve this control is important to know the formation mechanism of the material as function of parameters used. For this purpose, the effect of temperature (120, 140, 160 and 180 °C) on the hydrothermal synthesis of zinc sulphide is evaluated and a proposal of the sequence of reactions formation of zinc sulphur is presented. ZnS nanostructures with blend-phase were obtained, the temperature increment induces the growth of the nanostructure ranged between .62 and 12.72 nm, furthermore, increase the crystallinity of the ZnS nanostructures. The proposed reactions suggest the formation of a complex of thioacetamide with the Zn+2 and its subsequent decomposition into ZnS.

Surface functionality and porosity of activated carbons obtained from chemical activation of wood

Carbon ◽  
2000 ◽  
Vol 38 (5) ◽  
pp. 669-674 ◽  
Author(s):  
H Benaddi ◽  
T.J Bandosz ◽  
J Jagiello ◽  
J.A Schwarz ◽  
J.N Rouzaud ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Chemical Activation ◽  
Surface Functionality

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

Materials ◽  
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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