Three-dimensional Carbon Foam Research Articles

The polyoxometalates anchored onto three-dimensional carbon foam for efficient removal of water pollutants

Polyoxometalates are regarded as electron sponges in catalytic processes due to the capability of accommodating and releasing multiple electrons. However, the aggregation and high solubility in water pose challenges in reuse during the photocatalytic degradation of organic pollutants. Herein, we designed a large-scale preparable carbon foam support with three-dimensional porous structure and used the sol-gel method to tightly anchor cobalt-substituted Keggin-type polyoxometalates onto it. The composite (CoSiW11O39-CF-X) was characterized using SEM, FT-IR, Raman, XPS, etc. CoSiW11O39-CF-0.2 exhibits excellent photocatalytic degradation ability towards the MB with a rate constant of 8.62 × 10-3 min−1. The addition of carbon foam enhanced the separation and migration rate of photo-induced charges, thereby improving the photocatalytic efficiency. Additionally, the composite demonstrated excellent stability and reusability in four cyclic experiments. Meanwhile, The free radical capture experiments reveal that h+ and O2– were identified as the main active species contributors. Based on the energy band theory, a reasonable Z-scheme heterojunction mechanism has been proposed to explain the process of photocatalytic degradation.

A multi-functional flexible piezoresistive sensor based on sericin-functionalized CNTs decorated carbon foams for wearable thermal-therapy devices

With the rapid development of science and technology, multifunctional wearable devices have become a major trend in medical field. There is an urgent need to fabricate multifunctional materials with thermal insulation, mechanical flexibility, piezoresistance, and adjustable heating behavior to cope with the thermal management and health monitoring of human body in the harsh environment. To address this issue, three-dimensional melamine-based carbon foams (CMF) have been developed, with sericin-functionalized carbon nanotubes (CNTs) and in situ-grown carbon nanofibers (CNFs) in the CMF skeleton. The strategy of hierarchical porous micro-nanostructure enhanced the synergistic effect between CNTs and CNFs, resulting in exceptional resilience at 0–80 % compressive strain and cyclic stability at 20 % strain. Such carbon foam composites demonstrated excellent piezoresistive sensing performance, wide pressure range (0–20 kPa), high sensitivity (S = 0.11 kPa−1), and quick response (response/recovery time of 150/120 ms). They also showed good thermal insulation and Joule heating properties, particularly in presenting strain-dependent Joule heating mode at low voltage. Such amazing characteristics provide inspiration for temperature regulation of flexible, energy-efficient heating devices, and make them promising for smart sportswear, human-machine interfaces, and wearable medical devices.

Self-supporting hierarchical Co3O4-nanowires@NiO-nanosheets core-shell nanostructure on carbon foam to form efficient bifunctional electrocatalyst for overall water splitting

Designing cost-effective and robust bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly desired in hydrogen production from overall water splitting, but still suffers great challenges due to the sluggish catalytic OER/HER kinetics. In this paper, a surface/defect engineering strategy is developed to synthesize three-dimensional (3D) carbon foam (CF)-supported unique hierarchical Co3O4 nanowires@NiO nanosheets core–shell nanostructured catalyst (NiO@Co3O4/CF) with rich oxygen-vacancies as a novel bifunctional catalyst for alkaline water splitting electrolysis. Benefited from the synergy of the 3D hierarchical core–shell structure and rich oxygen vacancies, the as-obtained NiO@Co3O4/CF shows both excellent OER (η200 = 325 mV, η500 = 374 mV) and HER (η10 = 104 mV) activities with low Tafel slopes (64.26 mV dec−1 for OER and 109.14 mV dec−1 for HER, respectively) and outstanding stability. A simple overall water splitting electrolysis cell assembled by this bifunctional NiO@Co3O4/CF as both OER and HER catalysts requires only a cell voltage of 1.53 V to obtain the current density of 10 mA cm−2 and displays a long-term stability. This work has successfully developed an approach for rational design and novel synthesis of metal oxide hybrids as bifunctional electrocatalysts with high activity and stability for overall water splitting.

Three-dimensional hierarchical porous carbon surface-decorated graphitic carbon foam/stearic acid composite as high-performance shape-stabilized phase change material with desirable photothermal conversion efficiency

To simultaneously improve the photothermal conversion and encapsulation capacity of phase change material (PCM), a three-dimensional hierarchical porous carbon surface-decorated graphitic carbon foam (SGF) was developed. Employing this SGF as an encapsulated skeleton for stearic acid (SA), a unique shape-stabilized SA/SGF composite PCM was successfully prepared after vacuum impregnation. The porous carbon surface exhibits a uniform and fluffy three-dimensional continuous network structure well adhered onto the pore walls of the SGF; it can act as a desirable interfacial layer between SA and the SGF, which gives the composite effective encapsulation performance and good interfacial compatibility. The as-prepared composite has a loading capacity of 78.16% for melted SA without any leakage, and possesses a thermal conductivity of 3.25 W/mK with 1377% higher than that of SA and a compressive strength of 4.41 MPa (increasing 283.5% than the SGF). Further, the melting and crystallization enthalpy of the composite reaches 167.6 J/g and 167.5 J/g, respectively, with a thermal storage efficiency of up to 95.13%; meanwhile, it displays excellent thermal cycle stability revealed by keeping an enthalpy of 92.80% after 200 thermal cycles. More importantly, it presents a high photothermal conversion of 90.14% at 200 mW/cm2 with the ability to serve as a stable heat source during solar-thermal-electric conversion. Consequently, the composite has great potential in solar storage and waste heat recycle.

Porous CoO/carbon foam composites synthesized by solvothermal method for supercapacitor and enhanced microwave absorption applications

Composite materials comprising porous carbon foam and transition metal oxides exhibit significant potential for applications as supercapacitor electrodes and electromagnetic microwave absorbers. In this work, N-doped three-dimensional carbon foam was obtained by carbonizing melamine foam, and subsequently, a solvothermal method was used to construct a 0D/3D structure by integrating CoO nanoparticles with the three-dimensional carbon foam. The carbon foam serves dual purpose as a growth substrate and a conductive framework, effectively enhancing the electronic conductivity between the components and mitigating issues related to CoO nanoparticle aggregation. Due to the synergistic effect of pseudocapacitance and double-layer capacitance, CoO/CF exhibits enhanced supercapacitor performance, demonstrating an outstanding specific capacitance of 221 F g−1 at 1 A g−1, and surpassing that of individual component. The assembled asymmetric supercapacitor achieves a satisfactory energy density of 28.8 Wh kg−1 at a power density of 804.3 W kg−1, and retains 80.3 % of its initial capacitance after 5000 cycles at 10 A g−1. Furthermore, the microstructure was designed by the combination of carbon foam's excellent dielectric loss and CoO's magnetic loss compensating for the magnetic loss deficiency of carbon foam, thereby significantly enhancing the composite's capacity for electromagnetic wave absorption. At a thickness of 3 mm, the composite attains a minimum RL value of −14.1 dB at 14 GHz, with an effective absorption frequency width of 2.1 GHz. This well-designed and adjustable composite strategy holds great promise for applications in the fields of supercapacitors and microwave absorption.

Multifunctional three-dimensional porous MOFs derived Fe/C/carbon foam for microwave absorption, thermal insulation and infrared stealth

Multifunctional microwave absorbing materials with properties of high absorbing performance, infrared stealth, thermal insulation are urgently required to cope with current complex and extreme electromagnetic environment. To solve this problem, a three-dimensional carbon foam (CF) was used as a matrix, and Fe/C nanocubes derived from Prussian Blue (PB) were uniformly distributed throughout the CF skeleton. Such design of Fe/C/CF porous structures enhanced the synergistic effects between dielectric and magnetic loss to reach a better absorbing performance. The minimum reflection loss (RL) of hybrid foam is −66.7 dB, and the widest effective absorbing bandwidth (EAB, RL < −10dB) is 6.34 GHz. Moreover, the hybrid foam showed remarkable infrared stealth and thermal insulation properties. The surface temperature of hybrid foam almost unchanged while it was heated under 100 °C for more than 1 h. It is noteworthy that the preparation process of hybrid foam was a facile, recycled, and low-cost strategy for achieving high-performance absorbing materials. Besides, the mentioned methods may provide inspirations for the preparation of high-performance microwave absorbing materials and increase the potential application fields in complex actual scenarios.

Facile fabrication of three-dimensional carbon foam from fractionated corncob lignin

Facile fabrication of three-dimensional carbon foam from fractionated corncob lignin

Ultra-broadband microwave absorption of honeycomb-like three-dimensional carbon foams embedded with zero-dimensional magnetic quantum dots

The magnetic response behavior of microwave absorbing materials (MAMs) is beneficial to the expansion of the effective bandwidth in the high-frequency electromagnetic fields. However, the high density of magnetic components does not match with the lightweight requirement of MAMs. In response to this contradiction, the metal-organic framework (MOF) ZIF-67 material and melamine foam were used in the present work as the magnetic component and self-sacrificial template, respectively. A three-dimensional honeycomb carbon foam with zero-dimensional magnetic Co quantum dots (Co-QDs/CF) was prepared by a simple two-step method. The unique honeycomb structure significantly improved impedance matching and carrier mobility, providing more scattering paths for the electromagnetic wave conduction while reducing the overall density. In turn, the uniformly embedded magnetic Co-QDs endowed the 3D carbon foam with excellent high-frequency magnetic response while ensuring light weight. The ultra-small size (<10 nm) enhanced the exchange coupling between magnetic particles while suppressing the eddy current effect, and the magnetic loss capability was greatly improved. Interestingly, Co-QDs acting as numerous micro-resistors formed a large three-dimensional conductive network with the carbon skeleton, which demonstrated outstanding electron transport ability, so that the conductance loss was significantly enhanced. Surprisingly, the effective absorption bandwidth of Co-QDs/CF in the 2–18 GHz band was as high as 8.74 GHz with a matching thickness of 2.5 mm, while the corresponding filling rate was only 20 wt%. Thus, the proposed ingenious strategy to construct three-dimensional conductive networks using ultra-small magnetic quantum dots opens up new prospects for the development of lightweight broadband MAMs.

Three-dimensional carbon foam decorated with SnO2 as multifunctional host for lithium sulfur batteries.

Lithium-sulfur (Li-S) batteries with high theoretical capacity and abundant sulfur resources are potential energy storage systems. Nevertheless, there are several roadblocks that strongly limit the commercial application of Li-S batteries, including the insulating nature of sulfur and Li2S, large volume change and the shuttle effect of lithium polysulfides. Herein, a three-dimensional carbon foam (CF) decorated with SnO2 (SnO2/CF) is fabricated by the simple electrodeposition and used as a sulfur host to resolve the bottleneck issues in Li-S batteries. Thanks to the synergetic effect of the polar SnO2 and conductive carbon framework, the SnO2/CF framework is endowed with multifunctionalities such as providing three-dimensional conductive framework, inhibiting the migration of polysulfides and improved reaction kinetics. Consequently, durable cycle performance with a capacity of 458.2 mAh g-1 after 1000 cycles at 1 C is achieved. Furthermore, a high capacity of 749.5 mAh g-1 at a high rate of 5 C is attained. Remarkably, under high sulfur loading of 8.84mgcm-2, the S@SnO2/CF cathode can still deliver a high specific capacity of 389.8 mAh g-1 after 300 cycles at 0.5 C. This work demonstrates a novel strategy to improve the performance of Li-S batteries for energy storage applications.

Environmentally friendly a multifunctional cellulose-based carbon foam for superior electromagnetic wave absorption performance

Ingenious microstructure and suitable multicomponent are still challenging for designing lightweight, low-cost, and resource-renewable microwave absorption materials. Herein, environmentally friendly cellulose-based three-dimensional (3D) porous carbon foams were successfully prepared by freeze-drying and carbonization process. The pyrolysis process under gradient temperature could give rise to tunable electromagnetic (EM) parameters. The minimum reflection loss of carbon nanotubes/cellulose foam under 700°C is −55.4 dB (2.11 mm) at 9.27 GHz benefiting from the construction of double nano-interfaces so-called unique “1D-1D” combination, which can improve interface polarization and impedance matching. Furthermore, such carbon foam exhibits good thermal insulation and hydrophobicity, guaranteeing the stable and durable EM wave absorption application in the field of resist deformation, water or humid environments, and high-temperature attacks.

Three-Dimensional Carbon Foam Based Asymmetric Assembly of Metal Oxides Electrodes for High-Performance Solid-State Micro-Supercapacitor

Micro-supercapacitors hold great attention as one of the promising energy storage devices satisfying the increasing quest for miniaturized and portable devices. Despite having impressive power density, superior cyclic lifetime, and high charge-discharge rates, micro-supercapacitors still suffer from low energy density, limits their practical application. The energy density (E=1/2CV2) can be increased either by increasing specific capacitance (C) or voltage range (V). Asymmetric micro-supercapacitors have attracted great attention by using two different electrode materials to expand the voltage window and thus increase the energy density. Currently, versatile fabrication technologies such as inkjet printing, lithography, laser scribing, etc., are used to directly or indirectly pattern the electrode material; these techniques still suffer from scalable production and cost inefficiency. Here, we demonstrate the scalable production of a three-dimensional (3D) carbon foam (CF) based asymmetric micro-supercapacitor by spray printing technique on an array of interdigital electrodes. The solid-state asymmetric micro-supercapacitor comprised of CF-MnO positive electrode and CF-Fe2O3 negative electrode achieves a high areal capacitance of 18.4 mF/cm2 (2326.8 mF/cm3) at 5 mV/s and a wider potential window of 1.4 V. Consequently, a superior energy density of 5 µWh/cm2 is obtained, and high cyclic stability is confirmed with retention of the initial capacitance by 86.1% after 10000 electrochemical cycles. The optimized decoration of pseudocapacitive metal oxides in the 3D carbon network helps in high electrochemical utilization of materials where the 3D interconnected network of carbon provides overall electrical conductivity and structural integrity. The research provides a simple and scalable spray printing method to fabricate an asymmetric micro-supercapacitor using a custom-made mask that can be integrated on a large scale.

Morphologically and chemically regulated 3D carbon for Dendrite-free lithium metal anodes by a plasma processing

For the high theoretical specific capacity and low redox potential, lithium (Li) metal is considered as one of the most promising anode materials for the next generation of rechargeable batteries. In this work, we have developed an effective and accurate plasma strategy to regulate the surface morphology and functional groups of three-dimensional nitrogen-containing carbon foam (CF) to control the Li nucleation and growth. Besides the rougher surface induced by oxygen (O2) plasma, the conversion of carbon–nitrogen chemical bond (CN), namely, change from the quaternary N to pyrrolic/pyridinic N was realized by the nitrogen (N2) plasma. This chemical regulation of nitrogen boosts the lithiophilicity of carbon foam, which is evidenced by lower overpotential obtained from the experiment and higher binding energy for Li ions (Li+) calculated by density functional theory (-1.43, −1.85, −2.41 and −2.45 eV for the amorphous C-, C-quaternary N-, C-pyrrolic N- and C-pyridinic N-, respectively). The electrochemical performance of the half cells and full cells based on this plasma regulated carbon foam collectors also proved the prominent effectiveness of this plasma strategy on guiding the uniform dispersion of Li+ and thus inducing the homogeneous Li nucleation, as well as suppressing the growth of Li dendrites.

A highly compressible, nitrogen doped carbon foam based all pseudo-capacitance asymmetric supercapacitors

Compressible supercapacitors are playing an increasingly significant role in sensors and wearable electronic devices. However, compressible supercapacitors have a limited specific capacity as well as lower working voltage. In this work, three-dimensional (3D) N-doped carbon foam is being explored for fabrication of a compressible supercapacitor with pseudocapacitive spinel. The fact that self-growing ZnFe2O4 on highly compressible nitrogen doped carbon foam composite electrodes can deliver significant pseudo-capacitance at negative potentials, an all-pseudocapacitive asymmetric supercapacitor device is fabricated by combining it with NiCo2O4 cathode. The composite electrodes combine the superior electrochemical and mechanical performances with maximum compressive strain of 80% and durability (cyclic strains up to 500 times under the strain of 60%). The asymmetric supercapacitor demonstrates an energy density of 11.84 Wh kg−1 (0.39 mWh cm−3) at 300 W kg−1 (10 mW cm−3), with 96.5% capacitance retention after 15 000 charge-discharge cycles at the compressive strain of 60%. Our work provides new insights for the design of compressible supercapacitors with high performance and accelerates the development of a new generation in energy storage devices with compressibility.

Fe3C/Fe nanoparticles decorated three-dimensional nitrogen-doped carbon foams for highly efficient bisphenol A removal through peroxymonosulfate activation

The design of heterogeneous catalysts has become one of the most important steps in the popularization of advanced oxidation processes for wastewater remediation. With a nitrate-assisted polymer-bubbling strategy, we prepared three-dimensional carbon foams decorated by commensal Fe3C/Fe nanoparticles through a direct pyrolysis of the mixture of polyvinyl pyrrolidone and ferric nitrate nonahydrate. The as-obtained composites, Fe3C/Fe@NCFs, are employed as heterogeneous peroxymonosulfate (PMS) activators to remove bisphenol A (BPA) in aquatic environments with a predetermined concentration. It is found that both Fe3C/Fe nanoparticles and N-doped carbon frameworks can activate PMS to release powerful oxidative species for BPA removal. The effect of pyrolysis temperature on the catalytic performance of Fe3C/Fe@NCFs is studied in detail. The results reveal that high pyrolysis temperature induces the agglomeration of Fe3C/Fe nanoparticles and the loss of N content, and low pyrolysis temperature only generates low-crystallinity carbon frameworks and small proportion of graphitic N configuration. Therefore, Fe3C/Fe@NCFs from moderate temperature (700 °C) can produce the highest BPA removal efficiency. The synergy of Fe3C/Fe nanoparticles and N-doped carbon frameworks, as well as the structure advantages is clearly established in comparison with some control samples. Quenching experiments and electron paramagnetic resonance (EPR) tests indicate that BPA can be degraded in both radical pathway and non-radical pathway, where SO4−, O2−, and 1O2 are primary reactive species. In addition, the influences of some routine factors and actual water backgrounds were also investigated and analyzed comprehensively.

Bimetallic nanoarrays embedded in three-dimensional carbon foam as lightweight and efficient microwave absorbers

The rapid development of electronic information technology has promoted the use of a large number of high-frequency electronic equipment, which has led to increasingly serious electromagnetic interference (EMI) problems caused by disordered radiation. At present, for the 2–18 GHz microwave frequency band, it is still a huge challenge to develop high-efficiency absorbing materials with ultra-wide absorption band (>7 GHz) under thin thickness (<3 mm). Here, we propose a new strategy to achieve lightweight and high-efficiency microwave absorption by constructing hierarchical special structures. The melamine foam template was coated with a carbon/nickel/cobalt organic precursor by a hydrothermal process using a water/ethanol mixed solvent, and then annealed in an inert atmosphere at a high temperature to obtain a bimetallic nanoarray composed of nickel/cobalt embedded three-dimensional carbon foam (BNA/3dCF). This new type of absorbing material completely retains the structure of the melamine foam template, greatly enhances the conduction ability of micro-currents, and provides a large number of scattering sites for electromagnetic wave conduction. Interestingly, the protection of the carbon layer effectively avoids the oxidation of the bimetallic nanoarray, so that the BNA/3dCF retains the good dielectric properties of the carbon foam and has excellent magnetic properties, and improves the impedance matching and magnetic loss capabilities. With matching thicknesses of 2.2 mm and 3.9 mm, BNA/3dCF can respectively obtain an ultra-wideband microwave absorption of 7.16 GHz and a minimum reflection loss of −57.84 dB. We believe that through the macro/meso/micro multi-scale precise control of the absorbing material, it is an effective solution to enhance its absorbing performance.

Three-dimensional carbon foam modified with starlike-ZnO@reduced graphene oxide for microwave absorption with low filler content

Lowering the content of wave-absorbing fillers in composites can not only reduce the fabrication cost but preserve the processibility of matrix materials. Herein, via an in-situ crystallization combined with a dip-coating method, carbon-based composite foams decorated with ZnO@reduced graphene oxide (MF/ZnO@G) were prepared as microwave absorbers. Benefiting from the excellent impedance matching, elaborately constructed multiple polarization, and multiple reflections, the paraffin-based composite (4.1 mm in thickness) with 5 wt% MF/ZnO@G foam exhibited outstanding microwave absorption performance with a maximum reflection loss of − 63.2 dB and an effective absorption bandwidth of 6.2 GHz. This work provides a facile and efficient engineering strategy to fabricate high-performance microwave absorbers with low filler content.

Self-supported construction of three-dimensional NiCo2O4 hierarchical nanoneedles for high-performance microwave absorption

Grafting one-dimensional (1D) structure onto three-dimensional (3D) carbon foam is a practical and novel protocol to improve its microwave attenuation capability. Herein, a unique microwave absorber with NiCo2O4 nanoneedle grew on carbon foam (NCOCF) has been built via a combined approach of carbonization and hydrothermal treatment. The obtained NCOCF exhibit good impedance matching and excellent attenuation capability, which means that the microwave energy can be dissipated through conductive loss, interfacial polarization and multiple-scattering. These advantages result in the effective transformation of microwave energy to heat, thus yielding a remarkable microwave adsorption (with a thickness of 2.8 mm, the maximum reflection loss (RLmax) is −63.6 dB, and the effective absorption bandwidth (EAB) is as wide as 4.72 GHz with a thickness of 1.3 mm). The study would offer a strategy for development of the high-performance microwave absorber.

Novel electrode design of three-dimensional carbon foam modified with MnO2 nanosheet arrays for high-performance quasi-solid supercapacitor

Novel electrode design of three-dimensional carbon foam modified with MnO2 nanosheet arrays for high-performance quasi-solid supercapacitor

In-situ growth of molecularly imprinted metal–organic frameworks on 3D carbon foam as an efficient adsorbent for selective removal of antibiotics

In recent years, Metal-organic frameworks (MOFs) have attracted extensive attention in the field of adsorption owing to their advantages such as large specific surface area and rich active sites, but the adsorption performance of MOFs is not ideal for the removal of macromolecular organics. In this study, a novel composite material for the efficient and selective removal of norfloxacin (NOR) from wastewater has been successfully prepared via combining molecular imprinting (MI) technology and in-situ growth strategy, in which evenly dispersed MOFs particles are perfectly anchored to three-dimensional porous carbon foam (CF). Owing to more active sites exposed by three-dimensional imprinted holes and the excellent transport properties of CF, the as-prepared MI-MOF/CF exhibits a maximum capacity of 456 mg/g for NOR, which is far superior to that of the pristine MOF. Moreover, the adsorption rate is significantly increased, and the adsorption equilibrium could be reached within 60 min. Interestingly, the selective pharmaceuticals adsorption performance of MI-MOF/CF depends not only on the pore size, but also on the specific recognition ability of the active sites where modified with carboxyl compounds. This work effectively solves the bottleneck encountered by MOFs in the removal of large size antibiotic molecules, and provides a new direction for the design and synthesis of MOFs in the future.

Uniformly growing Co9S8 nanoparticles on flexible carbon foam as a free-standing anode for lithium-ion storage devices

Lithium-ion capacitor (LIC) possesses multiple merits of Faradaic and capacitive behaviors and shows excellent energy and power densities. Herein, Co9S8 nanoparticles embedded on melamine foam derived three-dimensional (3D) carbon foam (M-Co9S8@NCF) was successfully constructed by an in-situ anchoring and annealing method. When the composite was used as a free-standing anode electrode of lithium-ion battery, volume expansion effect is relieved and reaction kinetic is significantly improved benefitting from the synergistic effect of unique 3D carbon network and ultrafine nanoparticles. Therefore, the M-Co9S8@NCF free-standing electrode delivers superior rate performance (1024 mAh g−1 at 0.1 A g−1 and 468 mAh g−1 at 2 A g−1) and stable cycling performance (617 mAh g−1 at 1 A g−1 for 500 cycles). Moreover, porous nitrogen-doped carbon foam (PNCF) was synthesized as the cathode of LIC. M-Co9S8@NCF//PNCF LIC device was then fabricated to combine the advantages of battery-type anode and supercapacitor-type cathode, which achieves a high energy density (166 Wh kg−1 at 182 W kg−1), high power density (83 Wh kg−1 at 7674 W kg−1) as well as satisfactory capacitance retention (83.5% at 5 A g−1 after 5000 cycles). This work offers a convenient method to construct metal sulfide-based free-standing electrode for the advanced lithium-ion storage devices.