Synthesis Of Porous Carbon Materials Research Articles

Effect of asphalt component distribution characteristics in layered porous carbon on performance of supercapacitors

Petroleum asphalt, characterized by its rich aromatic hydrocarbon structures and high carbonization yield, emerges as an ideal precursor for generating porous carbons intended for supercapacitors (SCs). Despite asphalt's classification into four distinct components, the intricate composition due to its diverse sources still presents an unresolved challenge when it comes to elucidating the predominant structural characteristics underlying porous carbons. In the present investigation, we adopted potassium bicarbonate (KHCO3) as a templating agent, and the potassium-containing compounds were thermally polymerized with carbon-based free radicals to facilitate the synthesis of porous carbon materials through carbonization process. We observed that the fabricated porous carbon with a substantial content of heavy fraction (68.5 wt. %) demonstrated the maximal pore volume (1.02 cm3 g−1) and specific surface area (SSA) of 1229 m2 g−1, yielding in the power density of 625 W kg−1 at the energy density of 17.88 W h kg−1 used 1 M tetraethylammonium tetrafluoroborate in acetonitrile (TEATFB/AN). Notably, we corroborated the reliability of the entire process through a rigorous scaling-up experiment to 10 g, demonstrating entirely consistent performance. Our research introduces a novel avenue for strategically selecting petroleum asphalt precursors, with the overarching objective of producing cost-effective carbon materials endowed with commendable performance attributes.

One-step green synthesis of N-doped hierarchical porous carbon from glycine for high-performance symmetric supercapacitor

N-doped hierarchical porous carbon (NHPC) was facilely fabricated by a one-step pyrolysis of glycine and water-soluble Na2CO3, which is employed as a renewable water-soluble template without additional corrosive activating reagent. Benefiting from the hierarchical porous structure, high specific surface area (2735 m2 g−1) and the suitable nitrogen content of 3.84 at%, the obtained porous carbon exhibits a high specific capacitance (Csp) of 267 F g−1 at 0.2 A g−1 in a three-electrode system and 201 F g−1 at 0.2 A g−1 in the symmetric supercapacitor. More importantly, it shows an impressive rate capability of 102 % retention at 20 A g−1, outstanding cycling stability with 99.95 % of capacitance retention at 5 A g−1 after 10,000 cycles and a high energy density of 28.8 Wh kg−1 at a power density of 20 KW kg−1 in the symmetric supercapacitor. The results indicate that the synthesized NHPC obtained from this simple synthesis method would be an effective electrode material for symmetric supercapacitors, and this eco-friendly and easily scaled-up approach would provide a valuable strategy for the synthesis of porous carbon materials.

The synthesis of porous carbon material derived from coal liquefied residue and its electromagnetic wave absorption

To solve the problem of electromagnetic radiation pollution, it is necessary to develop an economic and environmentally friendly way of producing efficient electromagnetic wave absorbing materials. Carbon-based materials have attracted much attention but finding suitable precursors and ways of producing defined pore structures are still challenges. This work reported a facile method to produce porous carbon by using coal liquefaction oil residue as carbon source. The produced porous skeletons should be attributed to the generated Na2CO3 templates and CO2 gas during the thermal decomposition process of NaHCO3 templates. It is found that changing the pore structure not only adjusts the impedance matching of the material but also increases the length of the electromagnetic wave transmission path and increases dielectric loss. With the combined effect of multiple electromagnetic loss mechanisms, the material has excellent electromagnetic wave absorption. Specifically, with a filler loading of only 10% and a thickness of 2.03 mm, the obtained carbon material has a reflection loss value of −60.28 dB and an effective absorption bandwidth of 5.36 GHz. This work provides a new approach to developing high-performance carbon-based electromagnetic wave absorbing materials and also offers a new idea for the high value-added use of coal liquefaction oil residue products.

Boosting supercapacitor performance through the facile synthesis of boron and nitrogen co-doped resin-derived carbon electrode material

In this study, we present the synthesis of porous carbon materials designated as B, N co-doped porous carbon materials (PRNB), co-doped with boron and nitrogen through a two-step carbonization process of self-made phenolic resin. Among them, urea, boric acid, and potassium oxalate were used as the heteroatom dopants and activator, respectively. The co-doping of boron and nitrogen induced a unique electronic structure, resulting in improved capacitance performance compared to single-doped materials. Moreover, the addition of potassium oxalate as an activator facilitated the etching of the carbon framework during pyrolysis. Owing to the co-doping effect of boron and nitrogen and the abundant micropores, the PRNB material exhibited a remarkably high specific capacitance of 330 F g−1 at 1 A g−1. It also displayed excellent rate performance (70 %) and stability, with only a 6 % loss after 10,000 cycles compared to other materials. The symmetric electrode based on PRNB achieved an energy density of up to 29.7 Wh kg−1 in a neutral electrolyte, which provides a novel approach for resin-derived carbon to improve electrochemical performance.

Super microporous sulfur-doped hard carbon synthesized from a π-stacked Polybenzo[c]thiophene boosting reversible lithium-ion insertion at room temperature

Synthesis of porous carbon materials with controlled textural properties is an all-time challenging process for energy storage applications. Aromatic polymers possess high rigidity due to their π-π stacking arrangement and could serve as robust precursors to produce porous carbon. Herein, super-microporous sulfur-doped hard carbons (SM-SDHCs) were synthesized from a highly ordered aromatic polybenzo[c]thiophene between 600 and 800 °C by using KOH as an activation agent. The degree of carbonization and defects were enhanced as the temperature increased from 600 to 800 °C as confirmed by X-ray diffraction and Raman spectroscopy techniques. All the SM-SDHCs exhibit a super-microporosity (<2 nm) and high surface area (1126–1444 m2 g−1). Among the three synthesized carbons, the SM-SDHC800 exhibited a high discharge capacity of 760.7 mAh g−1 at 20 mA g−1 and showed excellent cycle stability at 200 mA g−1 for 250 cycles. The reversible lithium-ion insertion of SM-SDHC800 anode is accredited to its high degree of carbonization, defect-rich quality, high interlayer distance, and microporous texture with large pore volume (0.68 cm3 g−1). In addition, the excellent cycle stability at 2 A g−1 for 1000 cycles shows its robustness for high C-rate LIBs. Polybenzo[c]thiophene precursor is a perceptive choice to produce sulfur-doped super-microporous hard carbon with controlled textural properties and could bring dramatic advances in the synthesis of nanostructured carbon materials for energy storage applications.

Low-temperature organic solvent-based synthesis of amorphous porous carbon nanoparticles with high specific surface area at ambient atmosphere

The conventional synthesis of porous carbon materials is primarily relied on the activation and template process. This work successfully develops a one-step method for preparing amorphous porous carbon nanoparticles (APCNs) with a high specific surface area (SSA) in organic solvents under ambient atmosphere. The APCNs are formed mainly by the reaction of ferrocene with ammonium chloride at only 180 °C for 1 h in different solvents. Several ferrocene derivatives and KOH activation are also utilized to improve the textural properties of the APCNs. It is found that the high solubility of (C 5 H 5 ) 2 Fe and FeCl 3 ·6H 2 O in a solvent is the most essential factor associated with the decrease of carbon nanoparticle size. The smaller the nanoparticle size, the larger the SSA of APCNs. The APCNs prepared in phenoxyethanol have a median size of 32.74 nm, exhibiting an SSA of 689 m 2 /g. The high solubility of NH 4 Cl can also contribute to reducing the nanoparticle size. The binary solvent consisting of phenoxyethanol and glycol has an excellent solubility for (C 5 H 5 ) 2 Fe, FeCl 3 ·6H 2 O, and NH 4 Cl, in which the prepared APCNs have a median size 11.48 nm and a higher SSA of 936 m 2 /g. Besides, the benzoyl substituted group on the cyclopentadiene can facilitate formation of small mesopores. The oxygen and nitrogen are in situ doped in the APCNs. Activation is also effective, and the SSA of APCNs reaches a maximum value of 1575 m 2 /g at a KOH ratio of 2:1. The solvent-based synthesis is unique and competitive in terms of high efficiency and energy conservation. • A novel liquid-phase method for preparing amorphous porous carbon nanoparticles is developed based on an oxidation mechanism. • The synthesis is carried out at ambient atmosphere at 180 °C. • The specific surface area and pore volume are 936.11 m 2 /g and 1.45 cm 3 /g, respectively.

Optimal pore size design guided by GCMC molecular simulation for VOCs adsorption

Adsorption has been proved to be an effective control method of Volatile organic compounds (VOCs). However, the design of porous carbon materials with a high VOCs adsorption performance is still a challenging topic. Herein, we proposed a novel material preparation path, namely, the synthesis of porous carbon materials guided by molecular simulation. Firstly, the optimal adsorption pore size of VOCs was calculated by grand canonical Monte Carlo (GCMC) simulation, and then cork based porous carbon with the optimal pore size controlled by urea and KOH was prepared. The sample treated at 900 °C had a specific surface area of 1940 m2/g, a total pore volume of 1.27 cm3/g, a micropore volume of 0.71 cm3/g, which showed an excellent VOCs adsorption performance at 25 °C. Specifically, the dynamic adsorption capacity of acetone and toluene were 6.1 mmol/g and 5.4 mmol/g, and the static adsorption capacity of acetone and toluene were 17.5 mmol/g (18 kPa) and 9.5 mmol/g (3 kPa), respectively. In terms of the pore size distribution, the contribution of the optimal pore sizes to the adsorption process was estimated to be about 69% for acetone and 59% for toluene. Besides, the relationship between the optimal pore size and its adsorption capacity was explored by mathematical methods, which showed a highly linear one. This study provides a novel idea for the design and optimization of excellent adsorbent materials.

Accurately control the micropore/mesopore ratio to construct a new hierarchical porous carbon with ultrahigh capacitance and rate performance

The synthesis of porous carbon materials with high surface area is an important method to improving their specific capacitances. However, the misfitting distribution of micropore/mesopore leads to serious recession under high current densities. Herein, we report a set of combination methods to accurately control the micropore/mesopore ratio to achieve a hierarchical carbon material with ultra-large capacitance and extra-high rate performance. These methods include adjusting Al/Zn ratios, decarboxylation, zinc volatilization, removal of nano-Al2O3, and KOH–KCl activation. The first four contribute to micropore structure creation to increase the specific capacitance at low current, while the last one contributes to mesoporous structure formation to increase the specific capacitance at high current. It is found that the corrosion of the excess micropores to form new mesopores and transparent graphene greatly enhances ion diffusion kinetic process and rate performance. Based on these findings, the optimized MDAPC provides a superior specific capacitance of 433 F g−1 at 1 A g−1, 324 F g−1 at 200 A g−1, and 217 F g−1 at 750 A g−1, indicating its ultra-large specific capacitance and extra-high rate performance. These findings provide a research foundation for the future development of hierarchical porous carbon materials with outstanding capacitance, rate performance and durability.

Sol–Gel Synthesis of Porous Carbon Materials Using Nanocrystalline Cellulose as a Template

Sol–Gel Synthesis of Porous Carbon Materials Using Nanocrystalline Cellulose as a Template

Facile, two-step synthesis of activated carbon soot from used soybean oil and waste engine oil for supercapacitor electrodes

The present work deals with development of efficient, cost-effective supercapacitors capable of delivering electrical energy at high rates. This study depicts the green synthesis of porous carbon material using carbon soot (CS) collected from flames of oil-wick lamp, a method which is popularly used to make kajal in Indian demography. The activated carbon soot (ACS) was derived by burning used refined soybean oil and waste engine oil followed by chemical and thermal activation. The highest specific capacitance of the ACS-based EDLC supercapacitors was 44.8 and 61.4 Fg−1 at 0.5 mA cm−2 for soybean-based supercapacitor and engine oil-based supercapacitor, respectively, which shows the potential use of waste oils for electrochemical electrodes. Although the present study is focused on supercapacitor application, this work has broad environmental scope because it targets the efficient use of waste oils.

Bio-waste lemon peel derived carbon based electrode in perspect of supercapacitor

The delicate hierarchical structure of bio-waste is a cost-effective route to develop rational nanostructures for high-performance energy storage device. Bio-waste carbon materials receive extensive attention owing to their excellent physio-chemical properties and economic values. Herein, we demonstrate the facile route for the synthesis of porous carbon material from bio-waste without any physical/chemical activation and studied for supercapacitor application. The synthesized carbon materials exhibit a highest specific capacitance of 121 F g−1 at 1 A g−1 in three electrode system and 106 F g−1 in symmetric device at current density of 0.2 A g−1 with specific energy 11.84 Wh kg−1 and specific power of 361.8 W kg−1 with cyclic stability of 100% over 1000 cycles in device configuration. The effect of pyrolysis temperature with exclusion of the activation on the electrochemical performance is elaborated and hence the rational design of economic biomass-derived carbon material is studied for supercapacitor application.

Synthesis of porous carbon material based on biomass derived from hibiscus sabdariffa fruits as active electrodes for high-performance symmetric supercapacitors.

Carbon-based materials are manufactured as high-performance electrodes using biomass waste in the renewable energy storage field. Herein, four types of hierarchical porous activated carbon using hibiscus sabdariffa fruits (HBFs) as a low-cost biomass precursor are synthesized through carbonization and activation. NH4Cl is used as a chemical blowing agent to form carbon nanosheets, which are the first types of hibiscus sabdariffa fruit-based carbon (HBFC-1) sample, and KOH also forms a significant bond in the activation process. The prepared HBFC-1 is chosen to manufacture the symmetric supercapacitor due to its rough surface and high surface area (1720.46 m2 g−1), making it show a high specific capacity of 194.50 F g−1 at a current density of 0.5 A g−1 in a three-electrode system. Moreover, the HBFC-1 based symmetric supercapacitor devices display a high energy density of 13.10 W h kg−1 at a power density of 225.00 W kg−1, and a high specific capacity of 29 F g−1 at 0.5 A g−1. Additionally, excellent cycle life is observed (about 96% of capacitance retained after 5000 cycles). Therefore, biomass waste, especially hibiscus sabdariffa fruit based porous carbon, can be used as the electrode for high-performance supercapacitor devices.

Roles of structure defect, oxygen groups and heteroatom doping on carbon in nonradical oxidation of water contaminants

A rational design of structure-tailored and functionalized nanocarbons for peroxymonosulfate (PMS) activation is important in metal-free catalysis for degradation of water contaminants. In this work, we employed ionic liquids (ILs) for synthesis of porous carbon materials (PCMs) as a PMS activator for oxidative removal of naproxen and systematically investigated the functions of structure defects, oxygen functional groups and heteroatom doping toward the catalytic oxidation. A positive linear correlation between reaction rate constants and carbon defect ratios of PCMs revealed that the structural defects played an important role in PMS activation. Electron paramagnetic resonance (EPR) spectra, radical quenching experiments and electrochemical analysis tests verified nonradical-dominated oxidations via electron transfer and 1O2. Structural vacancies, ketonic C=O groups and graphitic-N atoms on carbons have been revealed to be the active sites for the nonradical pathways via direct electron transfer or generation of O2•−/1O2. This work provides new insight into the reaction mechanism and structure-performance relationships of the catalytic centers in nonradical oxidation.

The Use of Mechanical Activation of Polyvinyl Chloride in the Presence of Alkalis for Synthesis of Porous Carbon Materials

The synthesis of porous carbon materials was carried out by mechanochemical dehydrochlorination of polyvinyl chloride in the presence of alkalis (KOH, LiOH) using a high-energy planetary mill and the subsequent two-stage heat treatment of the obtained polyvinylenes (polymers with a conjugated double bond system)—carbonization to 400°C and carbon dioxide at 850°C or alkaline activation and 800°C, respectively. The structure of the obtained products was studied by Raman spectroscopy and transmission electron microscopy, analysis of isotherms of low-temperature adsorption/desorption of nitrogen. The resulting products are (micro-, meso-) porous amorphous carbon materials with specific surface SBET from 460 to 605 m2/g, micropore volume from 0.09 to 0.21 cm3/g, and mesopore volume from 0.09 to 0.6 cm3/g

Synthesis of porous carbon materials with mesoporous channels from Sargassum as electrode materials for supercapacitors

Using Sargassum as the precursor, a facile strategy was developed to synthesize three-dimensional porous carbons with mesoporous channels as high-performance electrode materials for supercapacitors employing aqueous ammonia pretreatment and KOH activation. Part of lignin was removed by the pretreatment of aqueous ammonia, which led to the swelling of biomass structure and the formation of unique mesoporous channels during the activation process. After being pretreated by 10 wt% aqueous ammonia, the specific surface area of the as-synthesized SAC-N 10 reached as high as 3251.42 m 2 g −1 with many mesoporous channels. Based on the unique structure, SAC-N 10 exhibited excellent electrochemical performance with a high capacitance of 336 F g −1 at 1 A g −1 and a good rate capacity of 82% retention at 10 A g −1 in a two-electrode system using 6 M KOH as the electrolyte. After being tested for 10,000 cycles at a current density of 5 A g −1 , SAC-N 10 retained 85.0% of the initial specific capacitance. The SAC-N 10 also showed a high energy density of 44.42 W h kg −1 and a power density of 2441.25 W kg −1 at a current density of 1 A g −1 in the voltage range of 0–1 V. • Porous carbons with mesoporous channels were synthesized from sargassum. • Aqueous ammonia pretreatment led to the formation of unique mesoporous channels. • A large surface area of 3251.42 m 2 g −1 with many mesoporous channels was achieved. • The carbon-based electrode exhibited a high capacitance of 336 F g −1 at 1 A g −1 .

Synthesis of porous carbon materials derived from waste buttonwoods, pineapple peels, and lettuce leaves and comparison of the electrochemical performances for lithium-ion battery

The waste buttonwoods, pineapple peels, and lettuce leaves have been activated by KOH and carbonized through a high-temperature process. When used as the anode materials for lithium-ion battery, the activated buttonwoods (BWs), pineapple peels (PPs), and lettuce leaves (LLs) can display that the first discharge capacities of BWs, PPs, and LLs are 313.9 mAh g−1, 296.6 mAh g−1, and 674.5 mAh g−1 and those of charge are 162.2 mAh g−1, 129.0 mAh g−1 and 357.2 mAh g−1, respectively. After 200 cycles, their discharge capacities are 164.8 mAh g−1, 96.1 mAh g−1, and 209.6 mAh g−1, respectively. In addition, the energy density of LLs is the highest among the three materials, while its capacity retention ratios are lower than those of BWs. It could be due to the high Si content of LLs, a honeycomb-like porous structure of BWs and high-specific surface area of BWs and LLs.

Synthesis Strategies of Porous Carbon for Supercapacitor Applications

AbstractSupercapacitors (SCs) have experienced a significant increase in research activity and commercialization during the past few decades. As the primary and most important electrode active material for commercial SCs, porous carbon is produced at an industrial‐scale through traditional carbonization‐activation strategies. Nevertheless, commercial porous carbon materials have some disadvantages such as high production cost, corrosion of equipment, and emission of toxic gases and byproduct pollutants during production. In recent years, huge efforts have been made to develop novel synthesis strategies for porous carbon materials. This review focuses on the pore formation mechanisms in traditional carbonization‐activation methods, emerging activation methods, template methods, self‐template methods, and novel emerging methods for the synthesis of porous carbons for SCs. Strategies developed so far for the synthesis of porous carbon materials are summarized. The mechanisms and recent advances for each strategy are reviewed. Furthermore, future directions and synthesis strategies for porous carbons are proposed.

Synthesis of porous carbon materials derived from laminaria japonica via simple carbonization and activation for supercapacitors

High-performance electrode materials derived from biomass for supercapacitors have been considered as an effective solution to the problems of the fossil energy shortage and the environment deterioration. Most importantly, the specific capacitance, rate performance and cyclic stability for these electrode materials are focused issues. Here, we prepare a new type porous carbon using laminaria japonica as the carbon source via a simple carbonization and activation method, and investigate its morphology, structure and electrochemical properties. The results show that the porous carbon materials exhibit amorphous structure, high specific surface area with abundant pores and oxygen functional groups. The specific capacitance of the porous carbon with a large specific surface area of 1902.42m2g−1 and total pore volume of 1.26cm3g−1 can reach to 192Fg−1 at 0.1Ag−1. Furthermore, this porous carbon possesses a specific capacitance of 120Fg−1 at 10Ag−1, nearly 100% capacitance retention rate and coulomb efficiency after 10000 cycles at 1Ag−1, indicating excellent rate performance and cyclic stability. Therefore, as-prepared porous carbons derived from laminaria japonica with low cost, easy availability, high regeneration ability and sustainability have a promising application as the electrode materials for supercapacitors.

Topology of Disordered 3D Graphene Networks.

Disordered carbons comprise graphene fragments assembled into three-dimensional networks. It has long been debated whether these networks contain positive curvature, as seen in fullerenes, negative curvature, as proposed for the schwarzite structures, or zero curvature, as in ribbons. We present a mesh-based approach to analyze the topology of a set of nanoporous and glassy carbon models that accurately reproduce experimental properties. Although all three topological elements are present, negatively curved structures dominate. At the atomic level, analysis of local environments shows that sp- and sp^{3}-bonded atoms are associated with line defects and screw dislocations that resolve topological complexities such as termination of free edges and stacking of low curvature regions into ribbons. These results provide insight into the synthesis of porous carbon materials, glassy carbon and the graphitizability of carbon materials.

Facile synthesis of three-dimensional interconnected porous carbon derived from potassium alginate for high performance supercapacitor

Porous carbon obtained by the conventional two-step way (chemical activation after carbonization) is confronted with the problems of long time-consuming, high cost and undeveloped macropore structure. Herein, for the first time, we report a facile and scalable way for the construction of three-dimensional (3D) interconnected porous carbons (IPC) originated from potassium alginate by a self-activation process. Owing to the high surface area, 3D interconnected ion diffusion channel and massive oxygen functional groups, the optimized IPC-800 electrode displays a high specific capacity of 279 F g−1 at 1 A g−1, superior rate capability (200 F g−1 at 50 A g−1) and excellent electrochemical stability with 96.6% capacitance retention after 10000 cycles in 6 M KOH aqueous electrolyte. Moreover, the assembled IPC-800//IPC-800 symmetric supercapacitor shows an energy density of 16.9 Wh kg−1 and good electrochemical stability in 1 M Na2SO4 aqueous electrolyte. These exciting results indicate a facile, economical and scalable method for the synthesis of porous carbon materials for high performance supercapacitors.