Properties Of Porous Carbon Materials Research Articles

Porous carbon prepared by thermal dissolution of coal and biomass for high-performance supercapacitors

Porous carbon materials have been considered a kind of promising materials for supercapacitors due to high specific surface area and excellent electronic conductivity. Soluble portions (SPs) acquired from thermal dissolution of carbon-based raw materials have been used as the carbon source for hierarchical porous carbons (HPC). In this work, mixtures of rice straw and coal at different mass ratios were selected as the raw materials for co-thermal dissolution to obtain SPX. The variation of soluble proportions and subsequent impacts on the electrochemical properties of HPCX were investigated. During thermal dissolution, the addition of rice straw increased the content of nitrogen-containing compounds in SPX. Therefore, the specific capacitance of HPC1/4 is 355 F/g. The specific capacitance of activated carbon material without rice straw is only 299 F/g. The relationship between the molecular characteristics of carbon source and the performance of supercapacitors has been determined. In addition to oxygen-containing compounds, the presence of nitrogen-containing compounds can also lead to a higher electrochemical property for porous carbon materials.

Ultrasonic treatment duration: A nuanced parameter in synthesis affecting structural properties and ORR performance of KOH-activated carbon

In this study, we investigate the effects of the duration of ultrasonic treatment during the impregnation process of a carbon precursor with an aqueous alkaline solution on the structural and electrochemical properties of KOH-activated carbon materials. Our findings using polyacrylonitrile (PAN)-derived carbon materials reveal that extended ultrasonic treatment leads to a more consistent distribution of the activating agent, promoting more uniform surface activation. This leads to notable shifts in the material's structure and surface chemistry, thereby influencing its functionality as an electrode material in supercapacitors and its electrocatalytic activity in the oxygen reduction reaction (ORR). Our results indicate a 6 % difference in the specific surface area and an 8 wt% rise in oxygen content when comparing samples without ultrasonic treatment to those treated for 10 min. Moreover, the specific capacitance increases from 133.9 to 163.5 F g−1, and the ORR activity ascends from 1.88 to 2.23 mA cm−2. This research highlights the potential of ultrasonic treatment duration as a variable to fine-tune the structure and properties of porous carbon materials, emphasizing its scientific and technological significance in the production of stable porous carbon materials.

Polyacrylonitrile-sodium lignosulfonate -derived nitrogen-doped three-dimensional hierarchical porous carbon for supercapacitors

Modulation of pore structure and heteroatom doping are very important strategies to improve the electrochemical properties of carbon electrode materials. This report investigates the use of biomass-derived nitrogen-doped porous carbon materials to address the challenge of the specific capacitance and energy density in supercapacitors. Nitrogen-doped three-dimensional hierarchical porous carbon materials were prepared using a polyacrylonitrile/sodium lignosulfonate composite monolith as a precursor by thermally induced phase separation and subsequent carbonization/activation. This method precisely controls the structure and surface properties of porous carbon materials by regulating the structure of the precursor and situ doping of nitrogen, which is a valuable strategy for the controllable regulation of the pore structure for nitrogen-doped porous carbon materials. The resulting carbon material displayed excellent capacitance performance, exhibiting a high specific capacitance of 325.7F g -1 at a current density of 0.5 A/g, maintaining initial capacitance retention of 90.1 % at a current density of 5 A/g after 10,000 cycles. When investigated for practical applications, the assembled supercapacitor device had a higher energy density (9.88 W h kg- 1), which is higher than commercial carbon-based supercapacitors.

Synthesis and electrochemical properties of porous carbon materials from sludge sources

Anaerobic digestion sludge technology is a green and efficient method of treating sludge. However, the presence of humic acid (HA) in sludge can inhibit methanogenic efficiency, and it is necessary to reduce its impact on biogas production by removal or pretreatment. HA, a graphene oxide material can be used to produce high-performance energy-storage materials. Thus, this study examined the sludge source of HA as a precursor, and different electrode materials were prepared by varying the reaction conditions. The structure and electrochemical properties of the electrode materials were analyzed. The results showed that the electrode material prepared using KOH as an activator at 700 °C exhibited optimal performance, with a high specific surface area (1480.53 m2·g−1), pore volume (0.943 cm3·g−1), specific capacitance (185.9 F·g−1), and equivalent series resistance (0.73 Ω). The material maintained 97.8% of its specific capacitance after 1000 cycles at a current density of 1 A·g−1 with benign cycle stability. This study confirmed that the production of HA as an electrode material at a low cost with good performance presents significant prospects.

Design of a Comprehensive Experiment for the Green Chemistry Preparation and Capacitive Properties of Porous Carbon Materials

Design of a Comprehensive Experiment for the Green Chemistry Preparation and Capacitive Properties of Porous Carbon Materials

Preparation and electrochemical properties of porous carbon materials derived from waste hollow fiber filter membrane

In this paper, waste hollow fiber filter membrane is used as a carbon source and KOH as an activator under an atmosphere of protective argon gas to prepare hollow fiber filter membrane-based porous carbon material ZKC-T via a high-temperature pyrolysis activation method. Hollow fiber filter membrane-based porous carbon ZKC-T was found to consist of amorphous carbon, with an irregular three-dimensional network interconnecting pore structure, specific surface area of up to 2934 m2 g−1, and a reasonable pore size distribution. Cyclic voltammetry and constant current charge and discharge tests showed that the hollow fiber filter-based porous carbon material ZKC-700 has excellent electrochemical performance. The carbon material shows a specific capacitance of up to 289 F g−1 at a current density of 1 A g−1 in 6 M KOH electrolyte. In addition, the material shows good cycle stability; after 5000 charge and discharge cycles, the capacitance retention rate is as high as 92.8%. The hollow fiber filter membrane-based porous carbon prepared by this method exhibits excellent electrochemical properties.

Preparation and Electrochemical Properties of Porous Carbon Materials Derived from Waste Plastic Foam and Their Application for Supercapacitors

Preparation and Electrochemical Properties of Porous Carbon Materials Derived from Waste Plastic Foam and Their Application for Supercapacitors

Structure-Morphological and Electroconductive Properties of Carbon Materials Based on Saccharose and Citric Acid

The article explores the effect of citric acid as a pore-forming agent on the structure, morphology and electroconductive properties of porous carbon materials (PCMs) obtained from carbon precursor (saccharose) using the methods of small-angle X-ray scattering, low-temperature porometry and impedance spectroscopy. It was found that the volumetric fractal structure is formed in the samples, and the fractal dimension Dv decreases from 2.15 to 1.91 with the addition of citric acid due to surface loosening. It was set that the use of 20 wt.% of citric acid causes the most effective modification of the porous structure of the material, i.e. an increase in specific surface area of 1.35 times, total pore volume of 1.14 times and a significant development of micro- and mesoporosity. It is shown that the use of citric acid as a pore-forming agent leads to an increase in the specific electrical conductivity of PCMs almost 5 times.

Porous Carbons: Structure‐Oriented Design and Versatile Applications

AbstractPorous carbon materials have demonstrated exceptional performance in a variety of energy‐ and environment‐related applications. Over the past decades, tremendous efforts have been made in the coordinated design and fabrication of porous carbon nanoarchitectures in terms of pore sizes, surface chemistry, and structure. Herein, structure‐oriented carbon design and applications are reviewed. The unique properties of porous carbon materials that offer them promising design opportunities and broad applicability in some representative fields, including water remediation, CO2 capture, lithium‐ion batteries, lithium–sulfur batteries, lithium metal anodes, Na‐ion batteries, K‐ion batteries, supercapacitors, and the oxygen reduction reaction are highlighted. Then, the most up‐to‐date strategies for structural control and functionalization of porous carbons are summarized, toward tailoring microporous, mesoporous, macroporous, and hierarchically porous carbons with disordered or ordered, amorphous or graphitic structures. Meanwhile, the emerging features of these structures in various applications are introduced where applicable. Finally, insights into the challenges and perspectives for future development are provided.

Friction and Wear Properties of Porous Carbon Materials made from Rice Hull at High Temperature

Friction and Wear Properties of Porous Carbon Materials made from Rice Hull at High Temperature

From Molecular Precursors to Nanoparticles—Tailoring the Adsorption Properties of Porous Carbon Materials by Controlled Chemical Functionalization

AbstractNanoporous carbon materials (NCMs) provide the “function” of high specific surface area and thus have large interface area for interactions with surrounding species, which is of particular importance in applications related to adsorption processes. The strength and mechanism of adsorption depend on the pore architecture of the NCMs. In addition, chemical functionalization can be used to induce changes of electron density and/or electron density distribution in the pore walls, thus further modifying the interactions between carbons and guest species. Typical approaches for functionalization of nanoporous materials with regular atomic construction like porous silica, metal–organic frameworks, or zeolites, cannot be applied to NCMs due to their less defined local atomic construction and abundant defects. Therefore, synthetic strategies that offer a higher degree of control over the process of functionalization are needed. Synthetic approaches for covalent functionalization of NCMs, that is, for the incorporation of heteroatoms into the carbon backbone, are critically reviewed with a special focus on strategies following the concept “from molecules to materials.” Approaches for coordinative functionalization with metallic species, and the functionalization by nanocomposite formation between pristine carbon materials and heteroatom‐containing carbons, are introduced as well. Particular focus is given to the influences of these functionalizations in adsorption‐related applications.

Nonlinear optical characterization of porous carbon materials by CARS, SHG and TPEF.

The Coherent anti-Stokes Raman scattering (CARS) microscopy is employed to characterize porous carbon materials. The slices of two dimensional (2D) CARS images are obtained, using Z-scan technology. Furthermore, the three dimensional (3D) image of CARS is reconstructed with the Z-scanned 2D CARS images. The visualizations of rotation for 3D CARS are also shown. The 2D and 3D CARS images with rotations can clearly characterize the structures and properties of porous carbon materials, including the surface and inner parts. Nonlinear optical second harmonic generation demonstrates the inversion symmetry breaking of porous carbon materials, which is not centrosymmetric material. The two-photon excitation fluorescence image reveals that porous carbon material is of weak auto-fluorescence. The clearly observed signal of two photon-excitation fluorescence provides direct evidence that photon momentum transfer to the electron system occurs. Experimental results demonstrate that the nonlinear optical microscopy is a great optical analysis method for the study of porous carbon materials, and can be potentially used for the optical characterization on the materials at micro-nano-scale.

Activated porous carbon derived from walnut shells with promising material properties for supercapacitors

Porous carbons derived from plant biomass have become the most competitive electrode materials for supercapacitors because of their renewability and sustainability. Here, activated carbons from walnut shells were fabricated by KOH activation with different mass loading and thermal pyrolysis process at temperatures between 500 and 900 °C in N2 air. The obtained activated carbons maintained the inherent structure after synthesis process and developed interconnected micro-, meso- and macro-pores. Not only the unique structure, but also many oxygen-containing functional groups contained were beneficial to enhance the electrochemical properties of porous carbon materials. With the honeycomb-like 3D pore network, carbon electrode materials exhibited a specific capacitance of 186.68 F g−1 at 0.5 A g−1, high rate capabilities and excellent cycling performance with about 100% capacitance retention over 20,000 charge–discharge cycles at 2 A g−1 in 6 M KOH electrolyte. The porous carbon from biomass walnut shells shows the potential of the application in energy storage.

Switching the electromagnetic properties of multicomponent porous carbon materials derived from bimetallic metal-organic frameworks: effect of composition.

Porous carbon materials have long been regarded as promising candidate for high-performance lightweight microwave absorption materials owing to their strong attenuation abilities, tunable dielectric properties and low density. Nevertheless, previous work mainly focused on binary composites (usually carbon and magnetic fillers), which show limited loss mechanisms. The effect (except temperature) on the interfacial polarization and electromagnetic properties has rarely been investigated. Thus, a series of bimetallic zeolitic imidazolate frameworks (BMZIFs) with designed compositions and highly porous structures were selected to be converted to porous carbon-wrapped semiconductors (ZnO, Co3ZnC) and magnetic metal (Co) composites. Strong dielectric loss capabilities could be provided by graphitic carbon and enhanced interfacial polarization induced by multiple components and unique microstructures. By changing the molar ratio of Zn/Co under a fixed carbonization temperature, the interface of this multicomponent system could be adjusted, which influenced the electromagnetic properties. When evaluated as microwave absorption material, a reflection loss of -32.4 dB could be achieved with a broad effective frequency bandwidth of 5.24 GHz at only 1.9 mm. This work may provide an effective method to modify the physical and chemical properties of porous carbon materials with a desired complex structure and excellent microwave absorption performance.

Production and properties of porous carbon materials from chemically modified microcrystalline cellulose

Certain fundamental aspects of how the porous structure is formed in carbon materials produced by pyrolysis of microcrystalline cellulose modified with phosphoric acid, potassium hydroxide, and zinc chloride were determined. The above chemical promoters shift the onset of the process of intense thermal transformation of cellulose to lower temperatures and promote formation of porous carbon materials. Water treatment of porous carbon materials produced by pyrolysis of microcrystalline cellulose with high content of a promoter leads to additional pore opening due to the removal of the excess amount of the promoter and soluble products formed in its interaction with cellulose, which makes it possible to obtain porous carbon materials with specific surface area of up to 1500 m2 g−1.

Свойства пористых углеродных материалов, полученных щелочной активацией термически модифицированной древесины осины

Свойства пористых углеродных материалов, полученных щелочной активацией термически модифицированной древесины осины

Effect of methods for thermal and alkaline modification of birch wood on properties of porous carbon materials obtained

Study of the carbonization of birch wood demonstrated that, under conditions of a preliminary carbonization at a temperature of 400°C, KOH favors better, compared with NaOH, development of the specific surface area (SBET ≈ 2000 m2 g−1) and microporous volume (0.6 cm3 g−1). The resulting porous carbon materials possess improved adsorption properties and are effective in separation of He(H2)-CH4 mixtures.

177 農業系副産物を利用した多孔質炭素材料の摺動特性(機械材料・材料加工/材料力学V,一般講演)

177 農業系副産物を利用した多孔質炭素材料の摺動特性(機械材料・材料加工/材料力学V,一般講演)

Synthesis and properties of porous carbon materials from natural cryptocrystalline graphites

The applicability of cryptocrystalline graphites as porous carbon materials was studied. The properties of the resulting products were examined with the use of various physicochemical methods of analysis.

Hierarchical Porous Core−Shell Carbon Nanoparticles

The excellent physical and chemical properties of porous carbon materials allow them to be widely used in many fields. Their performance in a specific application is usually determined by structural features such as pore diameter, channel length, and architecture. In recent years, great efforts have been made to develop suitable carbon-based materials with short pores and/or hierarchical porous architectures, for use in transport or diffusion of guest objects by reducing pathways and resistance. In the present paper, we report on a novel carbon nanostructure constructed with a mesoporous core and a microporous shell. The mesopore walls are constructed of only a few graphene layers and can be controllably removed by a wetting oxidation reaction, which leaves behind hollow nanoparticles. These short-pore structures could facilitate the diffusion of molecules; they also show a very high and stable catalytic performance during the dehydrogenation of cyclohexane that is far superior to currently available long...