Preparation Of Carbon Materials Research Articles

Preparation and Performance Analysis of New Multi stage Porous Carbon Materials for Air Pollution Treatmentials on Atmospheric Pollution Sources under the Background of Carbon Peak and Carbon Neutrality

The adsorption of toxic and harmful gases through porous materials is an effective means of air pollution control. A multi-level porous carbon material with ultra-high-specific surface area was made based on rice husk biomass to improve the air pollution controlling efficiency and reduce its cost. The rice husk substrate was pretreated using T.viride spore suspension during the preparation of this material. This changes the proportion of various components in the matrix, thereby achieving an increase in the multi-level porous carbon material’s specific surface area. Its performance was analyzed through various means in the study. The results confirmed that when the activation treatment time was 60 minutes, the porous carbon material’s specific surface area was the highest, reaching 3714 m2/g. After 30 days of treatment with T.viride spore suspension, the cellulose content in rice husks decreased by about 40 g/kg. Compared to untreated porous carbon materials, after 20 days of treatment, the micropores and mesopores of these materials significantly increased. The research has successfully increased the multi-level porous carbon material’s specific surface area and achieved rapid absorption of atmospheric volatile organic compounds. The multi-level porous carbon material can enhance the air pollution controlling efficiency and reduce its cost.

Co3V2O8 composite carbon hollow spheres bidirectionally catalyze the conversion of lithium polysulfide to improve the capacity of lithium‐sulfur batteries

Although lithium‐sulfur batteries have a high theoretical energy density that is higher than lithium‐ion batteries, their development is limited by the slow kinetics of lithium polysulfide conversion. In this research, we utilize the excellent bidirectional catalysis and adsorption of lithium polysulfide by the bimetallic oxide Co3V2O8 composite carbon hollow sphere to address the kinetic obstacle of lithium‐sulfur battery. On the one hand, the carbon hollow sphere substrate provides a cavity that can hold a large amount of sulfur. On the other hand, it can limit the diffusion of lithium polysulfide by van der Waals forces. The combination of the above two points improves the capacity and stability of lithium‐sulfur batteries. It has a specific capacity of 1237.2 mAh g‐1 at 0.2 C current density and retains 603 mAh g‐1 after 100 cycles. At a high current density of 2 C, the specific capacity is 976.2 mAh g‐1. After 1000 cycles, it holds at 338.3 mAh g‐1, and the capacity retention rate per cycle is 99.89%. This work discovers the new potential of Co3V2O8 as an electrocatalyst and proposes a process that can widely prepare carbon materials with complex uniform distribution of electrocatalysts to achieve high specific capacity of lithium‐sulfur batteries.

Preparation of Al-doped carbon materials derived from artificial potassium humate prepared from waste cotton cloth and their excellent Cr(VI) adsorption performance

Millions of tons of cotton textile waste are generated annually worldwide, and most of it enters the municipal solid waste (MSW) stream for landfill or incineration disposal, resulting in a significant waste of resources and environmental pollution. This article developed an innovative low-temperature pyrolysis process for producing artificial humic acid (HA) from waste cotton textiles. Subsequently, Al3+ was introduced for a secondary pyrolysis to prepare an Al-doped biochar (Al/BC) with superior adsorption properties. The experimental results show that the presence of Al3+ has an important influence on the pyrolysis process of cotton fabric and the formation and structure of Al/BC. This is the first time to synthesize low-cost adsorbent by pyrolysis and aluminum mixing process of waste cotton cloth and explains the mechanism. This increased in defects (ID/IG = 0.76 to ID/IG = 0.92), a larger specific surface area (6.47 m2/g to 566.94 m2/g), and an increase in oxygen-containing functional groups (from none to C-O-C, OC-O, etc.) when compared to the undoped Al3+ biochar. The optimum Al3+-doped biochar (Al/BC-15) prepared with HA as a precursor exhibited a superior adsorption capacity for Cr(VI) of up to 176.23 mg/g, surpassing the results reported for similar materials in the literature. The adsorption mechanism of Cr(VI) is primarily based on physical adsorption, with some chemical adsorption. At a lower pH, the Al/BC-15 surface exhibits a high positive charge (46 mV). The Al3+-O-Cr(VI) association group is formed through rapid electrostatic attraction between C-Al and Cr(VI). Due to the strong positive electronegativity of Al3+ and the negative electronegativity of C in the vicinity of Al, Cr(VI) is further reduced to Cr(III) by C-Al. Therefore, the method proposed in this paper for preparing Al-doped carbon materials from waste cotton fabric offers a new approach and potential application for the production of high-performance adsorbent materials from waste cotton fabric.

Activation-free preparation of porous carbon fiber derived from phenolic resin for CO2 absorption

BackgroundIt is not uncommon to study the preparation of porous carbon materials for CO2 adsorption, but it is still a challenge to simultaneously achieve the good mechanical strength, porous structure, and efficient adsorption performance of porous carbon fibers. MethodsPorous carbon fibers with desirable morphology and selective CO2 adsorption were prepared using an activation-free method. The fibers were prepared through melt spinning of phenolic resin modified with polyvinyl butyral (PVB) and urea, followed by curing treatment, and then the pore structures were adjusted by controlling the carbonization temperature. Significant findingsThe porous carbon fibers prepared by carbonization at 900 °C not only had excellent CO2 adsorption (3.48 mmol/g) but also possessed desirable tensile strength (132 MPa). Those carbonized at 700 °C showcased CO2/N2 selectivity of 57 (Ideal adsorption solution theory (IAST), CO2: N2 =15:85), and tensile strength of 148 MPa, much higher than most fibers using other methods. The study revealed that the adsorption of CO2 was mainly performed by nitrogen-containing groups and physical function through pores ranging from 0.3 nm to 0.8 nm, and the micropores between 0.3 nm and 0.6 nm were conducive to the selective adsorption of CO2/N2.

Eco-friendly preparation of nitrogen-doped porous carbon materials for enhanced solid-state supercapacitor device

In the last years, researchers all over the world have been looking for biomass-derived porous carbon materials, due to the possibilities for large-scale synthesis, easy to control the pore structure, and high specific surface area. Activated heteroatom doped porous carbon (AHPC) with a high porosity was made by treating inexpensive waste Ficus elastica leaves with a base. The electrochemical performance of the produced activated carbon has been evaluated in various electrolytes, including basic, neutral, and acidic electrolytes. At a current density of 1 A/g in the acidic electrolyte, the specific capacitance of the activated carbon AHPC electrode is higher, 456 F/g, compared to other electrolytes. The symmetric supercapacitor device is built using PVA-H2SO4 gel electrolyte, and its electrochemical performance is evaluated. In addition, the energy density of the built symmetric supercapacitor device is higher than the existing commercial supercapacitors, achieving 62 Wh/kg at a power density of 15.2 kW/kg. This is because the porous carbon has a hierarchical pore distribution and a heteroatom-enriched structure, which allows for rapid charge/mass diffusion channels, and a vast ion-accessible network.

Electroadsorption desalination performance of carbon materials derived from coconut shell without membrane separation

This study investigated coconut shells, an abundant and low-cost raw material, as the precursor for activated carbon preparation, and applied a carbonization activation method to prepare carbon materials under different activation conditions. The differences in the performance of biomass derived carbon materials as capacitive deionization (CDI) electrodes were studied under conditions of different activators, activator doses, and activation temperatures. Compared with commercial coconut shell activated carbon, studies have shown that biomass derived carbon electrodes obtained under the optimal preparation conditions of NaOH as the activator, a carbonizer to activator ratio of 1:3, and an activation temperature of 800 ℃ have an excellent electro adsorption performance and the potential to be used as a CDI electrode material. The salt adsorption capacity (SAC) of activated carbon made with coconut shell derived carbon materials after 20 min of electro adsorption reached a maximum of 11.47 mg/g. After 10 repeated uses, its SAC remained at the original 90.58%, demonstrating an excellent cycling stability.

Efficient Template-Catalyzed In Situ Polymerization for Carbon Xerogels with Large Specific Surface Area and High Adsorption.

The limited specific surface area (SSA), long preparation period, and high cost are significant challenges for carbon xerogels (CXs). To overcome these limitations, we propose an approach to prepare tannin-resorcinol-formaldehyde-based CXs through template-catalyzed in situ polymerization. ZnCl2 acts as a catalyst and significantly accelerates the polymerization reaction through the coordination of Zn2+ to the carbonyl group in formaldehyde, while atmospheric drying instead of special drying and without solvent exchange reduces the preparation period to 24 h. In addition, ZnCl2 acts as an activator for the formation of many pores. Plant-derived tannins not only reduce the preparation cost but also regulate the pore structure. The resulted CXs with hierarchical porous structures show an optimal SSA of 1308 m2/g, high adsorption capabilities (for cationic, nitrosoaniline dyes, metal, and nonmetallic ions, especially for methylene blue with 454.93 mg/g), low shrinkage down to 10%, and reusability with 92.9% retention after 5 cycles. This work provides a promising and cost-effective method for the large-scale preparation of porous carbon materials with large SSA, offering potential applications in adsorption, energy storage, and catalysis.

Preparation of natural N/O/S co-doped biomass-derived carbon materials for supercapacitors using multistage gas self-exfoliation effect

High-value utilization of biomass provided a feasible way to solve the energy shortage and environmental problems. The preparation of micro-mesoporous composite carbon materials from biomass waste as feedstock using a multistage gas self-exfoliation mechanism (CH3COOK and Ca2(C2H5COO)2) was a feasible approach. Among them, the N, O and S co-doped carbon materials were obtained in this paper by using forestry waste (bamboo) as raw material, spiral algae as green heteroatom dopant, Ca2(C2H5COO)2 as multifunctional template agent, and CH3COOK as gentle activator. The results indicated that BC-SA-0.5CP exhibited 324.85 F/g at 0.5 A/g. The symmetric supercapacitor (BSC-0.5//BSC-0.5) achieved 96.02% capacitance retention after 10,000 cycles, indicating excellent rate performance and charge/discharge stability. At a power density of 162.5 W/kg, the BSC-0.5//BSC-0.5 had an energy density of 14.67 Wh/kg. In addition, it was deeply analyzed the growth mechanism of heteroatoms, the formation mechanism of porous carbon and the electron transfer routes, which provided a theoretical basis for the preparation of biomass-derived carbon materials. Overall, this study demonstrated that the multistage gas self-exfoliation mechanism was beneficial in promoting the formation of micro-mesoporous composite structures and the growth of heteroatom functional groups, which ultimately provided a new route for the synthesis of natural heteroatom-doped porous carbon.

Salted Dried Bamboo Shoots-Derived Mesoporous Carbon Inherently Doped with SiC and Nitrogen for Capacitive Deionization.

Dried bamboo shoots (DBS) are a natural resource with inherent silica content, which can serve as sacrificial templates for the formation of mesoporous carbon but also promote the generation of silicon carbide (SiC). Building on this, we introduced mesoporous and graphitic carbon/SiC (SiC/BSC) as the CDI electrode for copper ion (Cu2+) removal. Mesoporous carbon electrodes facilitate faster ion transport, diffusion, and electron-transfer pathways. Furthermore, SiC accelerates electron transfer and promotes faradic redox reactions during the charge and discharge processes. Consequently, the synergistic effect of SiC/BSC mesoporous carbon material leads to a promising electrode for Cu2+ capacitive deionization. Leveraging these unique properties, the SiC/BSC electrode material exhibits an outstanding CDI performance of 381.5 mg/g at 1.8 V. This study offers a strategy for the preparation of efficient mesoporous carbon materials as CDI electrodes, specifically tailored for the deionization of Cu2+ ions.

Preparation and electrochemical performance of cellulose-based biomass-derived carbon materials

Biomass-derived carbon materials are regarded as an ideal precursor for activated carbon owing to their unique structure, widely used in energy storage applications. Porous biomass carbon materials were prepared by high-temperature carbonization and activation methods using corn stalk stem pith as the carbon source. The structures and morphology of biomass-derived carbon materials were also characterized and analyzed, and it was employed as the electrode material to study the electrochemical properties. The results showed that the specific surface area and pore volume increased with the increase of temperature under the action of the same activator. The activation degree of carbon materials by different activators showed obvious differences under the same temperature conditions, and the structure and properties of the carbon materials obtained by sodium hydroxide activation were better than those obtained by sodium bicarbonate activation. When the temperature was fixed at 900 ℃, the carbon materials obtained by sodium hydroxide activation showed the best structural characteristics and electrochemical properties, with the specific surface area up to 532.881 m2·g−1 and the microporous volume accounting for 76.266 % of the total pore volume. By cyclic voltammetry test, the specific capacity was 139 F·g−1 at a scan rate of 10 mV·s−1, and the electrochemical impedance was much smaller than the impedance of the product obtained by sodium bicarbonate activation. Meanwhile, the specific capacity remained basically unchanged after 1000 cycles of charging and discharging, with excellent cycling stability and electrochemical performance. The relevant results provide a new way for the efficient utilization and functionalization of biomass resources.

Recent Progress on Porous Carbons for Carbon Capture.

High emission of carbon dioxide (CO2) has caused CO2 levels to reach more than 400 ppm in air and led to a serious climate problem. In addition, in confined spaces such as submarines and aircraft, the CO2 concentration increase in the air caused by human respiration also affects human health. In order to protect the environment and human health, the search for high-performance adsorbents for carbon capture from high and low concentration gas is particularly important. Porous carbon materials, possessing the advantages of low cost and renewability, have set off a boom in the research of porous adsorbents, which have the opportunity to be utilized on a large scale for industrial carbon capture in the future. In this review, we summarize the recent research progress of porous carbons for carbon capture from flue gas and directly from air in the last five years, including activated carbon (AC), heteroatom-modified porous carbon, carbon molecular sieves (CMS), and other porous carbon materials, with a focus on the effects of temperature, water content, and gas flow rate of industrial flue gas on the performance of porous carbon adsorbents. We summarize the preparation strategies of various porous carbons and seek environmental friendly porous carbon materials preparation strategies under the premise of improving the CO2 adsorption capacity and selectivity of porous carbon adsorbents. Based on the effects of real industrial flue gas on adsorbents, we provide new ideas and evaluation methods for the development and preparation of porous carbon materials.

MgO templated carbons: Effect of synthesis methodology on the morphology, surface chemistry and supercapacitor performances

Templating method is a widely adopted route to prepare porous carbon, while the effect of methodology on the structure and performances of the derived porous carbon was rarely focused. Herein, we employed a commercial MgO as template and catechol/formaldehyde as starting materials to prepare porous carbon by incipient impregnation method (the derived product denoted as MgC-I) and aqueous self-assembly method (the derived product denoted as MgC-S), respectively. Systematically analysis indicates that impregnation method favors the construction of two-dimensional structure, while, aqueous self-assembly method benefits formation of densified structure. Concerning to the surface chemistry, aqueous self-assembly method enables more residual oxygenic functionalities than that of impregnation derived ones. As electrode for supercapacitor in aqueous electrolyte, the MgC-S achieves superior volumetric performances including high specific volumetric capacitance of 319 F/cm3@1.0 A/g and large energy density of 27.9 Wh/L@1193 W/L, showing a potential for practical energy storage devices. Whereas, in organic electrolyte of 1.0 M TEANBF4/AN, the MgC-I electrode show a superior energy storage ability with energy density of 40.5 Wh kg−1@1350 W kg−1, the value is about six times higher than that of MgC-S based one. This study provides a reference for how to choose synthesis methods for preparing carbon materials with specific target.

Research progress on lignin-based carbon electrode materials in rechargeable batteries

Lignin, with its carbon content of up to 60%, can be an ideal precursor for the preparation of carbon materials. Carbonaceous materials obtained from lignin can be transformed into porous and structural morphologies at different scales, providing a biomass approach to energy conversion and storage in batteries. Focusing on lignin-derived carbon materials, this paper summarizes the different morphologies and structures of lignin-based carbon obtained through different preparation methods, and the different electrochemical properties exhibited by these materials as electrode materials for rechargeable batteries (lithium-ion batteries, sodium-ion batteries, lithium-sulphur batteries, etc.). In addition, the development prospects and challenges of lignin-based carbon materials in the field of rechargeable batteries are summarized, providing ideas for the next step in the design and development of high-performance lignin-based carbon-based electrode materials.

Construction of Bimetallic-Anchored Two-Dimensional Nanosheets on COF for Rechargeable Zinc-Air Batteries.

The preparation of carbon materials by doping bimetallic oxides into triazine frameworks (COFs) is a promising electrocatalyst with the potential to replace precious metals in energy storage systems. In this experiment, a covalent triazine framework (COF) was synthesized by 1,4-dicyanobenzene (DCB) and zinc chloride, in which the COF and transition metals were used as carbon, nitrogen, cobalt, and iron sources. According to the properties of this COF, the destruction of the catalyst during pyrolysis can be prevented. The enhanced catalytic performance of the catalysts can be seen by testing all of the samples of catalysts in an alkaline medium. The high half-wave potential (E1/2) of 0.86 V is comparable to Pt/C and also shows excellent durability by testing. Zinc-air batteries were assembled using the prepared catalysts, and the batteries were tested for specific capacity (548 mAh g-1) and power density (189 mW cm-2). This work provides a new direction for COF-derived catalysts for carbon materials.

Preparation and Characterization of Porous Carbon Material from Banana Pseudo-Stem

In this work, pseudo-stem of a banana plant was used as a sustainable and affordable source to prepare porous carbon materials (PCM) on a large scale. After fine treatment, the material was annealed at 500, 600, and 700 °C using a tube furnace under nitrogen flow. The prepared materials were characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). FT-IR spectra show that the broad peak at the range of 1110-1160 cm-1 comes from the superimposed peaks of C-N for a single or more than one functional group which debunks the possibility of generating nitrogen-doped carbon. TEM and SEM analyses confirmed the porous structure of PCM with the pores connected to one, and a spongy structure was observed in the prepared carbon material. XRD analysis revealed that the carbon materials are crystalline. XPS investigation provided information regarding the dimension of which elements are present in the valence states and constituent elements, depicting the presence of a dominant graphitic C1speak at approximately 284 eV, along with a distinct O1s peak at around 532 eV. Additionally, a relatively weaker N1s peak (approximately 400 eV) was observed. Dhaka Univ. J. Sci. 72(1): 63-70, 2024 (January)

N,S‐Co‐Doped Activated Carbon Prepared by a Thiourea‐Assisted “Cutting” Method and their Application as High‐Performance Supercapacitors

AbstractBiomass has been considered a potential source for preparing carbon materials due to its environmentally friendly and renewable characteristics. In this work, N, S co‐doping activated carbon materials were easily prepared by using rice straw as the carbon source. In addition to being heteroatom source, thiourea can fragment the carbon particles into smaller pieces and create plenty of micropores during the carbonization process. Both theoretical and experimental analyses demonstrate that the incorporation of S and N species into carbon can improve the electrochemical performance of supercapacitors. The as‐made N, S co‐doping activated carbon materials, when used as electrodes, exhibit a high specific capacitance of 256 F g−1 at a current density of 1 A g−1 and maintain a good rate capacitance of 65 % even at a high current density of 50 A g−1. This work may offer valuable guidance for the application of rice straw derived carbon in supercapacitors.

Preparation and Electrochemical Performance of Activated Composite Carbon Nanofibers Using Extraction Residue from Direct Coal Liquefaction Residue

Organic carbon extracted from direct coal liquefaction residue (DLCR) is an ideal precursor for the preparation of carbon materials. However, investigations into the utilization of the extraction residue (ER) are rarely reported. In this work, ER from DCLR was pretreated with H2O2 to afford oxidized extraction residue (OER). Then, the OER was mixed with polyacrylonitrile (PAN) in N,N-dimethylformamide for the preparation of composite carbon nanofibers by electrospinning. With adding 80 wt.% OER, the composite carbon nanofibers still demonstrate a clear fiber profile and smooth surface under a scanning electron microscope, indicating that the OER has good solubility with PAN in N,N-dimethylformamide. The electrochemical performance characterization of the activated composite carbon nanofiber shows that the P-OER60-AC (activated composite carbon nanofibers prepared with 60 wt.% of OER and 40 wt.% of PAN) has a better electrochemical performance with a specific capacitance of 97 F/g at 0.5 A/g, as compared to the others. Additionally, the P-OER80-AC (activated composite carbon nanofibers prepared with 80 wt.% of OER and 20 wt.% of PAN) is also considerable for the perspective of coal-based solid waste treatment and utilization.

Rapid preparation of P/O doped nano-porous carbon by microwave method for high-performance supercapacitors

This paper proposes a simple and rapid microwave-assisted phosphorus-oxygen doped porous carbon (P/O-PC) preparation strategy is proposed using potassium citrate, Phytic acid (PA), and ethanol under air atmosphere. PA can be used as both a phosphorus source and a microwave absorbing agent. The P/O-PC500–0.75 has a large specific surface area of 905 cm2/g. P/O doping introduces defects into the carbon structure, which enhances the capacitance of the porous carbon. The P/O-PC500–0.75 demonstrates excellent capacitance values of 330 F/g and 389.4 F/g in 6.0 M KOH and 1.0 M H2SO4, respectively (1 A/g). In addition, the symmetrical supercapacitors assembled with the P/O-PC500–0.75 exhibit good electrochemical stability over 5000 cycles at 5 A/g, with a capacitance loss of only 3.6%. This microwave-assisted strategy offers simplicity in operation and low energy consumption, providing a new and efficient pathway to prepare carbon materials in a fast and simple manner.

Pretreatment of poplar powder by light bio-oil for preparation of porous carbon materials with excellent electrochemical performance

Reasonable pretreatment strategies play a crucial role in enhancing the pore structure and electrochemical performance of porous carbon materials (PCMs). In this paper, the light bio-oil, as one of the by-products of biomass pyrolysis, was proposed to pretreat poplar powder to investigate the influence on the properties of the PCMs obtained under ZnCl2 activation. The Scanning electron microscopy (SEM) analysis showed that the surface morphology of the biomass was seriously destroyed by light bio-oil treatment. And, the relative crystallinity of the biomass increased after the treatment based on the X-ray diffraction (XRD) analysis. Correspondingly, the obtained PCMs with the help of light bio-oil treatment have the better reasonable hierarchical pore structure and electrochemical performances. The specific surface area of PCMs obtained from light bio-oil pretreatment together with ZnCl2 activation at 500 °C reached 2063.8 m2/g. Its specific capacitance reached 306.5 F/g at 0.5 A/g. The symmetric supercapacitor assembled with the corresponding PCMs also exhibited excellent performance. The energy density reached 8.69 Wh kg−1 at 125 W kg−1. After undergoing 10,000 cycle tests, the capacitance retention rate was 98.46 %. This paper can provide some reference significance on the pathway for the preparation of supercapacitor electrode materials from biomass resources.

Heteroatom-doped porous carbon materials for high performance supercapacitors

Heteroatom-doped carbon materials have considerable potential for applications in energy storage devices (ESDs). In this study, an interconnected B/N/O/P co-doped porous carbon materials (B5-CPPCN-700) was synthesised using a simple one-step method with zinc nitrate hexahydrate and 4′-(4-phosphonylphenyl)−3,2′:6′,3″-terpyridine as raw materials through KOH activation. The as-prepared B5-CPPCN-700 had a large specific surface area, rough surface for ion adsorption, and suitable pore size distribution for electron transport. Moreover, the co-doped B/N/O/P species—particularly the B species—in B5-CPPCN-700 provided active sites and additional pseudocapacitance. These structural and morphological features ensured a high specific capacitance of 503.3 F/g at 0.5 A/g. Furthermore, the assembled symmetric supercapacitor delivered a satisfactory specific energy, specific power (14.98 Wh/kg at 300 W/kg and 6.97 Wh/kg at 22,800 W/kg), and specific capacitance (149.8 F/g at 0.5 A/g and 77.2 F/g at 40 A/g). This study paves the way for the preparation of high-capacitance porous carbon materials for ESDs.