Carbon Aerogels Research Articles

Carbonaized carbon aerogels derived from pomelo peels for sorption of some organic solvents

Carbonaized carbon aerogels derived from pomelo peels for sorption of some organic solvents

Biomass-based carbon aerogels prepared by ZnCl2-assisted pyrolysis of cellulosic aerogels for selective electrocatalytic CO2 reduction

Carbon aerogel is a promising electrodes material for electrocatalytic CO2 reduction reaction (CO2RR) due to its hierarchical porous structure and large specific area. However, using renewable and wide-sourced precursors to prepare green catalysts with comparable commercial CO2RR performance is still a challenge. Herein, a green ZnCl2-modified biomass-based carbon aerogel was fabricated. The cellulose and ZnCl2 were used as a biomass model compound and activator, respectively. The results showed that the morphology of carbon aerogels can be controllable by thermal etching between ZnCl2 and aerogel under different pyrolysis temperature. At low pyrolysis temperatures (below 750 °C), the carbon aerogel exhibited three-dimensions hierarchical pore structure with abundant ZnO, which was conducive to the conversion of CO2 to CO. As the temperature raised, ZnO rapidly decreased and eventually disappeared. At 950 °C, the unique flocculent structure with rich defects was formed, and the main conversion products changed from CO (a maximum faradic efficiency of 78%) to syngas (CO:H2 =1:1).

Preparation of nanocellulose-based nitrogen-doped carbon aerogel electrocatalysts through hydrothermal pretreatment for zinc–air batteries

A cellulose-based nitrogen-doped carbon aerogel with abundant micro-mesopores for zinc–air batteries with high open-circuit voltage and long cycle stability was prepared by hydrothermal pretreatment and simple carbonization.

Fluorine doped carbon aerogel prepared from spent cathode carbon of aluminum electrolysis towards electrocatalytic synthesis of H2O2

The sustainability of aluminum electrolysis spent cathode carbon (SCC) is currently an urgent environmental issue that needs to be addressed. In this work, fluorine doped carbon aerogels (SCC-FCA) were prepared...

Effect of fluorine functional groups introduced into activated carbon aerogel by carbon tetrafluoride plasmas in supercapacitors

Effect of fluorine functional groups introduced into activated carbon aerogel by carbon tetrafluoride plasmas in supercapacitors

Composite Carbon Aerogels Containing Manganese Oxide: Synthesis via Thermo-Oxidative Decomposition of Mn2(CO)10 in Supercritical CO2

A new effective approach is suggested that allows for introducing nanosized highly dispersed particles of manganese oxide into carbon aerogels using the thermo-oxidative decomposition of Mn2(CO)10 dissolved in supercritical CO2. It is shown that the proposed procedure retains a branched porous structure of the material with a specific surface area of more than 600 m2/g. The resulting composite aerogels contain 4–16 wt % of manganese.

Nano-Fe3O4 decorated on carbon aerogel framework: Coupling microstructures synergistic effect for electromagnetic wave absorption

Generation of multi-components synergistic absorbers is of value for efficient electromagnetic wave (EMW) absorption. This study constructed two kinds of nano-Fe3O4 decorated carbon aerogels with disparate microstructures (either Fe3O4 nucleated on the surface of carbon skeleton or the pore inside the aerogel) and highlighted the significance of the coupling microstructure on the EMW absorption capacity of the magnetic-dielectric material. The results demonstrate that the readily Fe3O4 coated and distributed carbon aerogel favors to improve EMW absorbing performance. A minimum reflection loss (RLmin) value of −51.8 dB is achieved at 4.9 GHz. In addition, the effective absorption bandwidth (EAB) covered the Ku bands under the matching thickness of only 1.8 mm. The favorable impedance matching and abundant hetero-interfaces collectively contribute to the EMW attenuation. The work with respect to interfacial structural control is of great reference value for designing excellent EMW absorber candidates.

Preparation and Characterization of Carbon Aerogel Based on Main-Chain Benzoxazine

Preparation and Characterization of Carbon Aerogel Based on Main-Chain Benzoxazine

Microwave-mediated ultrafast solid-state construction of O vacancies enriched cobalt oxide/nitrogen carbon aerogel toward efficient tetracycline degradation with peroxymonosulfate

A rapid microwave assisted carbonization of dicyandiamide and cobalt nitrate was developed for the first time to prepare cobalt oxide/nitrogen carbon aerogel materials, in which cobalt oxide species were uniformly loaded with the characteristics of multivalent Co species. Moreover, the rapid heating process introduced abundant oxygen vacancies and N containing heterocycles in Co@NC3A materials. The optimal Co@NC3A exhibited complete TC degradation within 10 min with a rate constant up to 0.8609 min−1 at 25 °C. Meanwhile, the Co@NC3A also had general applicability in various antibiotics and dyes degradation. Radical quenching experiment and EPR test revealed the coexistence of radical and non-radical activation process in Co@NC3A/PMS system. Multivalent Co species could activate PMS to facilitate the SO4•- and •OH production. In addition, 1O2 and direct electron transfer mediated non-radical pathways were accelerated with O vacancies and N containing heterocycle.

Synthesis of Metal-Free Carbon Aerogel with Nitrogen-Doped from Pyrolysis of Cellulose Aerogels Based on Coir Fibers Using Ammonia-Urea System as Electrocatalyst of Oxygen Reduction Reaction for Cathode in Seawater Batteries

Performance of seawater batteries is still limited by the sluggish nature of oxygen reduction reaction (ORR). One way to optimize the performance of the battery is by utilizing an electrocatalyst with the ability to increase the ORR rate of reaction. Nitrogen-doped carbon aerogel based on coir fiber is one of the alternatives because of its excellent electrocatalytic performance and was made from an abundant material. Carbon aerogel was obtained from pyrolyzing coir fiber-based aerogel cellulose. Nitrogen atom structure in carbon aerogel was affected by the temperature of cellulose aerogel pyrolysis. Pyridinic N content in the Nitrogen-doped carbon aerogel has effective for the activity of the ORR. The electrocatalytic performance of the carbon aerogel synthesized from coir fiber with nitrogen doping at the pyrolysis temperature of 600 °C was investigated in this study. The research process began with the synthesis of cellulose aerogel using urea-ammonia crosslinking precursor. Next, cellulose aerogel was pyrolyzed at 600 °C to create carbon aerogel. FTIR, XRD, CV, LSV, and LP were used to characterize the samples. The carbon aerogel was N-doped with pyridinic N, according to an analysis of the FTIR spectra. The carbon aerogel shows 4-electron ORR with kinetic current density (ik) of 0.74 mA/cm2 and current density (io) of 0.583 μA/cm2, according to electrochemical performance analysis in 3.5% NaCl as electrolyte.

Synthesis and Characterization of N-Doped Carbon Aerogel Based on Oil Palm Empty Fruit Bunch as Oxygen Reduction Reaction Electrocatalyst in Seawater Batteries

Some areas in Indonesia have difficulty accessing electricity [1]. One of the alternative is sea water battery because of its good theoretical performance and great seawater potential in Indonesia [2]. However the performance is limited by the sluggish Oxygen Reduction Reaction, therefore electrocatalyst is needed to increase the rate of reaction [2]. Oil palm empty fruit bunch carbon aerogel is one of the alternative because of its excellent electrocatalytic performance and can be made from abundant material with high content of cellulose [3]. Carbon aerogel can be obtained from pyrolizing oil palm empty fruit bunch based aerogel cellulose. Activity of the Oxygen Reduction Reaction can be determined from pyridinic N concentration in the carbon aerogel [4]. This research focuses on synthesizing nitrogen-doped carbon aerogel from oil palm empty fruit bunch and characterized its electrocatalytic performance. Research started with synthesizing cellulose aerogel with urea-ammonia crosslinking precursor and followed by pyrolysis of cellulose aerogel to carbon aerogel at 600°C. Samples were characterized using FTIR, XRD, CV, LSV, and LP. The FTIR Spectra analysis shows that the carbon aerogel was N-doped with pyridinic N. Electrochemical performance analysis in 3.5% NaCl as electrolyte shows that carbon aerogel undergoes 2-electron ORR pathway with kinetic current density of ik=0.107 mA/cm2 and current density of io=0.295 μA/cm2.

Synthesis of Sulfonated Carbon Aerogel from Coir Fiber as Solid Acid Catalyst for Esterification

The increasing human population drives up energy consumption, particularly in the transportation and industrial sectors. Due to the limited and non-renewable availability of fossil fuels encourages various technological developments in the field of renewable energy, including biodiesel. Biodiesel is a biodegradable, non-toxic, and environmentally favorable renewable fuel. One of typical technique of biodiesel production is involving esterification reaction between fatty acids and alcohols by addition acid catalyst to enhance reaction rate. Solid acid catalysts are widely utilized for esterification reaction due to their ability to overcome the drawback of homogeneous catalysts that are difficult to separate. Solid acid catalysts can be produced from cellulose aerogel derived from coir fiber, which is then pyrolyzed into carbon aerogel and sulfonated through grafting process. Although sulfuric acid is a common sulfonic agent used in the catalyst sulfonation process, it has a lengthy grafting time. The addition of 4-aminobenzenesulfonic acid (sulfanilic acid) as a sulfonic agent alternative for sulfuric acid was investigated in this work. This paper reports the methods for preparing cellulose aerogel derived from coir fiber, pyrolysis of cellulose aerogel into carbon aerogel, sulfonation of carbon aerogel into solid acid catalyst, and application of solid acid catalyst for ethyl acetate production. The solid acid catalyst characterization tests include acid density, adsorption-desorption nitrogen analysis, SEM, and FTIR analysis. According to the adsorption-desorption nitrogen analysis results, the sulfonated carbon aerogel catalyst has a specific surface area of 220.29 g/m2. Sulfonated carbon aerogel catalyst with acid density value of 2.81 mmol/g can be obtained at the mass ratio of sulfanilic acid to carbon substrates of 1:1 and pyrolysis temperature of 700°C. The esterification reaction was carried out at 80°C and reached a conversion of 31.37% after 4 h.

Design of an effective air electrode using highly porous carbon‐aerogel on carbon cloth for oxygen intake toward improved reaction kinetics of aluminum‐air battery

AbstractOne of the greatest alternatives to Li‐ion batteries is an Al‐air battery as it is more economically feasible and less toxic together with relatively better electrochemical performance. The design of the cell and the selection of electrode for improved electrochemical performance are the primary factors influencing the performance of the Al‐air battery. The present study focuses on designing an efficient air cathode host to lengthen the battery's lifespan using highly porous carbon aerogel. Initially, the carbon aerogel (CA) material is synthesized using sol‐gel polymerization process and characterized using XRD, RAMAN, SEM, and BET. The synthesized CA is used to fabricate the electrode stacking using the in‐house‐built Al‐air cell. The performance of carbon aerogel coated on carbon cloth as air cathode has been evaluated using a galvanostatic discharge of the assembly at different current rates, and the specific capacity is recorded. The highest specific capacity observed is ~683 mAh g−1 at 2.551 mA cm−2 current density. The acquired results demonstrate the superiority of the present electrodes material compared to currently used air electrode. The improved electrochemical stability and the robust pore network in CA allow oxygen to pass through the cathode end for chemical reaction. Overall, this enhances kinetics and makes the interactions between oxygen and aluminum easier to generate higher current.

Ruthenium,nitrogen-codoped carbon aerogels for real-time electrochemical monitoring of cellular hydrogen peroxide release

Hydrogen peroxide (H2O2) is an important signaling molecule for diverse biological functions, and it is thus of importance to develop sensing platforms for real-time monitoring of cellular release of H2O2. Herein, a H2O2 electrochemical sensor is constructed based on ruthenium,nitrogen-codoped carbon aerogels. The nanocomposites are prepared by controlled pyrolysis of a biomass hydrogel with RuCl3, where RuNx single-atom sites and Ru nanoclusters are incorporated into the aerogel scaffold, as confirmed by high-angle annular dark-field scanning transmission electron microscopy and X-ray photoelectron spectroscopy measurements. In cyclic voltammetry and amperometric analysis, the aerogels exhibit a remarkable H2O2 detection performance, with excellent sensitivity and selectivity, wide linear range (0.1 μΜ ∼ 1 mM) and low detection limit (0.01 μM). The sensor can also be used for real-time monitoring of hydrogen peroxide released from MCF-7 cells and screening of anticancer drugs, displaying a high potential for biosensing and biomedical diagnostics.

Metal-Organic Frameworks-Derived FeS-Co9S8/NCA Porous Aerogel Electrocatalyst as a High-Performance Cathode for Zinc-Air Batteries.

Herein, a novel strategy to establish a porous FeS-Co9S8/carbon aerogel (FeS-Co9S8/NCA) electrocatalyst for oxygen evolution reaction (OER) is fabricated via applying a green biomass carrageenan sulfuration method to CoFe-metal-organic frameworks (MOFs). The FeS-Co9S8/NCA exhibits optimized catalytic activity toward the OER with a lower overpotential of 322 mV, which is overmatched to the majority of transition metal sulfides (TMSs), as well as lifted long-term durability without evident variation in the LSV curves after 3000 cycles. Rechargeable liquid zinc-air battery (ZAB) assembled with FeS-Co9S8/NCA as the OER catalyst indicated a maximum power density of 176 mW cm-2 and superior cycling stability without raised polarization even after 48 h, outperforms commercial RuO2-based ZAB. Furthermore, the flexible solid-state ZAB built with FeS-Co9S8/NCA also demonstrated outdistance properties and bendability. The excellent performance stems from the hierarchical porous aerogel structure, which offers a multiscale mass/electron transport channel, together with the interfacial synergy effect between FeS and Co9S8, which serves as the active site of the OER reaction. Thus, this work instituted a novel strategy for obtaining both clean and efficient transition metal sulfide electrocatalysts for the OER reaction and an environmentally friendly biomass material-based sustainable electrocatalyst.

Longevous Cycling of Rechargeable Zn-Air Battery Enabled by "Raisin-Bread" Cobalt Oxynitride/Porous Carbon Hybrid Electrocatalysts.

Developing commercially viable electrocatalyst lies at the research hotspot of rechargeable Zn-air batteries, but it is still challenging to meet the requirements of energy efficiency and durability in realistic applications. Strategic material design is critical to addressing its drawbacks in terms of sluggish kinetics of oxygen reactions and limited battery lifespan. Herein, a "raisin-bread" architecture is designed for a hybrid catalyst constituting cobalt nitride as the core nanoparticle with thin oxidized coverings, which is further deposited within porous carbon aerogel. Based on synchrotron-based characterizations, this hybrid provides oxygen vacancies and Co-Nx -C sites as the active sites, resulting from a strong coupling between CoOx Ny nanoparticles and 3D conductive carbon scaffolds. Compared to the oxide reference, it performs enhanced stability in harsh electrocatalytic environments, highlighting the benefits of the oxynitride. Furthermore, the 3D conductive scaffolds improve charge/mass transportation and boost durability of these active sites. Density functional theory calculations reveal that the introduced N species into hybrid can synergistically tune the d-band center of cobalt and improve its bifunctional activity. As a result, the obtained air cathode exhibits bifunctional overpotential of 0.65V and a battery lifetime exceeding 1350 h, which sets a new record for rechargeable Zn-air battery reported so far.

Self-floating, monolithic, and aligned phenolic carbon aerogels from coal tar for solar-driven evaporation

Polycyclic aromatics in low-temperature coal tar (LTCT) make it to be notorious and it is urgent to develop value-added utilization technologies of LTCT. On the other hand, solar-driven evaporation has attracted much attention owing to high energy efficiency and zero carbon emission. However, it is limited to expensive photothermal materials and external supports. In this paper, self-floating and monolithic coal tar-based phenolic carbon aerogels (CPCAs) were facilely constructed. Polycyclic aromatics in LTCT endow CPCAs strong light absorption and photothermal conversion superior to carbon nano tube. Additionally, CPCAs possess fast water transportation owing to their excellent hydrophilicity and aligned hierarchical channels. Moreover, water molecular states can be easily regulated, thus reducing evaporation enthalpy. Combining with these characteristics of CPCAs, water evaporation rate and energy efficiency can reach to as high as 1.81 kg m-2h−1 and 93.4 %, respectively. In addition, high compressive strength, good salt-tolerance, durability, and versatility facilitate CPCAs practical applications.

Facile preparation of high-strength SiC/C aerogels from pre-reacted resorcinol–formaldehyde and siloxane

Carbon aerogels are ideal thermal insulation materials in the field of aerospace. However, their poor oxidative resistance at high temperatures is a significant drawback. Therefore, there is considerable interest in developing SiC/C aerogels. In this study, using pre-reacted resorcinol–formaldehyde gel (RF) as the carbon source, homogeneous silica/phenolic resin (SiO2/RF) hybrid aerogels were prepared via atmospheric pressure drying using a simple process. The SiC/C aerogels were subsequently obtained via carbon thermal reduction. As the C/Si ratio decreased (from 6 to 4.5 and 3), the density, thermal conductivity, and compressive strength of the aerogels decreased from 0.19 to 0.26 g·cm−3, 0.0330 to 0.0983 W/(m·K), and 0.57 to 4.83 MPa, respectively. The linear shrinkage rate was 16.4–18.3 %, which is lower than those of most reported SiC/C aerogels. Here, the carbon improved the strength of the SiC-based aerogels while maintaining their thermal insulation characteristics. A composite material prepared using the relatively low-strength aerogels and mullite fibre felt could achieve long-term insulation at 1400 °C in an air environment. This study lays the foundation and outlines various options for achieving an optimal balance between the strength and thermal conductivity of SiC/C aerogels for industrial applications.

Biomass carbon aerogels by polyatomic synergistic modification and synchronous activation for supercapacitors

The regulation and modification of carbon aerogel are essential for the construction of supercapacitors electrode with high energy density. Heteroatom doping has also been used in the modification of carbon aerogels to further improve the properties of materials. In this work, nitrogen and sulfur co-doped porous biomass carbon aerogels (NSPCs) for high-performance supercapacitors were innovatively synthesized by a straightforward and highly efficient one-step gel and synchronous activation strategy. Such a covalently interconnected hierarchical porous structure with co-doped nitrogen and sulfur greatly improves the pore structure and wettability of the materials and forms functional groups to provide additional pseudocapacitance. Owing to these structural advantages and the component synergy, the NSPCs exhibit high electrolyte ion storage ability, unhindered ion channels, and excellent electrochemical performance, and display a specific capacitance of 344.3 F g−1, and a capacitance retention rate of 91.5 % after 10,000 cycles. Additionally, the NSPCs-based symmetric supercapacitor showed a high energy density of 12.82 Wh kg−1.

Tissue‐derived highly compressible anisotropic carbon aerogels with aligned fibrous matrices for solid‐state rechargeable zinc‐cobalt‐air hybrid batteries

AbstractThe rising demand for wearable zinc‐air batteries encounters challenges in balancing electrochemical performance and mechanical resilience. Elastic carbon aerogels in air cathodes necessitate a metal content constraint of less than 3 wt.%, adversely impacting catalytic activity optimization. This study presents a novel fabrication method for fibrous carbon aerogels with high compressive resilience and extraordinary catalytic performance. An external layer of graphene shells and carbon nanotubes integrated onto the fibrous carbon matrix mitigates metallic species diffusion. This confinement ensures exceptional bi‐catalytic activity for oxygen‐involved redox reactions without compromising ultra‐elasticity. With high cobalt content in the aerogel cathode, it exhibits minimal voltage gaps during charge–discharge cycles, showcasing unique zinc‐cobalt‐air hybrid battery characteristics. It sustains exceptional elasticity in repeated testing, achieving approximately 79.2% round‐trip efficiency over a 60‐h cycle test, underscoring its potential as a wearable energy storage device.image