Three-dimensional Carbon Network Research Articles

Highly thermally conductive and shape-stabilized phase change materials with desirable solar/electric-to-thermal conversion performance based on high-modulus graphite/PVA foam

The widespread utilization of phase change materials (PCMs) has been impeded by challenges such as leakage, low thermal/electrical conductivity, and inadequate light absorption. Although constructing interconnected three-dimensional (3D) carbon networks within PCMs can mitigate these issues, their complex and energy-intensive fabrication processes, coupled with insufficient mechanical strength causing significant leakage and collapse of liquefied PCMs under external loads or impacts, hinder their practical application. Herein, we present a novel approach for the preparation of 3D graphite/polyvinyl alcohol foam (GPF) through a simple vacuum foaming combined with air-drying method. The obtained GPF-5 exhibits impressive compression strength (4.46 MPa) and compression modulus (93.1 MPa) at low density of 0.30 g/cm3. Upon impregnation with polyethylene glycol (PEG), GPF-5/PEG exhibits notable mechanical strength (7.62 MPa), contributing to its thermal shape stability and resistance to leakage. Even when subjected to temperatures above the melting point of PEG under external loads, GPF-5/PEG maintains its original shape without any liquid leakage. Due to the efficient construction of 3D thermal conductivity pathways within GPF, GPF-5/PEG demonstrates a high thermal conductivity of up to 3.48 W/m K−1 with graphite contents of 21.1 wt%, representing an increase of 136 % and 1640 % compared to graphite/PEG (with equivalent graphite content) and pure PEG, respectively. Additionally, GPF-5/PEG displays high latent heat of melting (136.8 J/g) and superior thermal cycling stability. Moreover, GPF-5/PEG demonstrates high solar-to-thermal and electric-to-thermal energy conversion capabilities, highlighting their potential for diverse applications. The work offers a rational strategy for fabricating high-modulus carbon foam, which can be used for PCMs-based multi energy conversion and storage systems with high thermo-mechanical properties.

The collaborative effect of Ni3S2-NiO heterojunction and porous carbon network modified lithium-sulfur battery separator for effectively inhibiting polysulfides shuttle

As an important part of lithium-sulfur battery (LSB), separator not only provides ion transport channel but also plays a key role in ensuring battery safety. However, the aperture of the commercial separator polypropylene (PP) is relatively large, which cannot effectively inhibit the migration of polysulfides generated during the charging and discharging process between the positive and negative electrodes, resulting in a decrease in the cycle stability of LSB. In this work, a modified LSB separator Ni3S2-NiO@AC-4@PP is designed, which is anchored by Ni3S2-NiO heterojunction on volcanic rock-like three-dimensional porous carbon network (AC) as the functional interlayer. The AC possesses a large specific surface area and excellent electrical conductivity, creating sufficient space for the physical and chemical adsorption of insoluble polysulfides. The Ni3S2-NiO heterojunction is embedded and attached to the AC, which helps to hinder the diffusion of polysulfides and accelerate the redox reaction. It is also confirmed by density functional theory (DFT) calculation that Ni3S2-NiO heterojunction inhibited the shuttle of polysulfides through the adsorption capacity of NiO and the catalytic activity of Ni3S2. Thus, the Ni3S2-NiO@AC-4@PP battery exhibits an elevated initial specific capacity of 1027.8 mAh g−1 at 0.2C, maintaining long-term stability after 200 cycles with the capacity retention rate of 81.4 %. At the higher current density (2C), Ni3S2-NiO@AC@PP battery demonstrates durable cycle with the capacity retention rate of 91.3 %. This study proposes a new feasible strategy to obtain high-performance, low-cost modified separators by designing functional interlayers with excellent adsorption and catalytic properties.

Three-Dimensional random network of metacomposites by synergizing Multi-Walled carbon Nanotube-Carbon black for tunable Epsilon-Negative and Epsilon-Near-Zero responses

Epsilon-near-zero (ENZ) and epsilon-negative (EN) responses are remarkable properties of electromagnetic (EM) metamaterials that have sparked considerable interest. This paper introduces an innovative strategy using ternary metacomposites that achieve excellently tunable ENZ (|ε’| < 1) and EN (ε’ < 0) parameters within the radio-frequency band. The approach leverages a synergistic effect of multi-walled carbon nanotube-carbon black (MWCNT-CB) composites integrated into a polyaniline (PANI) matrix to construct three-dimensional (3D) carbon networks. As the loading content of MWCNT-CB increases, these networks evolve from clusters, enabling a finely tunable range of EN parameters from 100 to 103. The ENZ response occurs at approximately 265 MHz and 830 MHz, triggered by dielectric resonance due to electric dipoles at MWCNT-CB/PANI interfaces and a low-frequency plasmonic state in the 3D MWCNT-CB networks, respectively. This research establishes a foundation for tunable ENZ and EN responses by introducing a new class of ternary metacomposites.

Co/Ce-MOF-Derived Oxygen Electrode Bifunctional Catalyst for Rechargeable Zinc-Air Batteries.

Improving the practicality of rechargeable zinc-air batteries relies heavily on the development of oxygen electrode catalysts that are low-cost, durable, and highly efficient in performing dual functions. In the present study, a catalyst with atomic Ce and Co distribution on a nitrogen-doped carbon substrate was prepared by doping the rare earth elements Ce and Co into a metal-organic framework precursor. Rare earth element Ce, known for its unique structure and excellent oxygen affinity, was utilized to regulate the catalytic activity. The catalyst prepared in this study demonstrated an exceptional electrocatalytic performance. At a current density of 10 mA cm-2, the catalyst exhibited an overpotential of 340 mV for the oxygen evolution reaction (OER), which was lower than that of commercial IrO2 (370 mV), while achieving a half-wave potential of 0.79 V for the process of oxygen reduction reaction (ORR), exhibiting a similar level of effectiveness as commercially accessible Pt/C catalysts (0.8 V). The catalyst's porous structure, interconnected three-dimensional carbon network, and large specific surface area are the factors contributing to the significant improvement in catalytic performance. Furthermore, in comparison to commercial Pt/C+IrO2, the catalyst exhibited good cycling stability and high efficiency in rechargeable zinc-air batteries.

Sodium alginate derived SiC-carbon composite aerogel for effective microwave absorption

Biomass-derived carbon aerogels are expected to be ideal candidates for electromagnetic wave (EMW) absorption due to their extensive sources, cheap cost, low density and abundant porosity. Herein, using the natural polymer sodium alginate (SA) as the carbon-based precursor and SiC nano-whiskers (SiCw) as the reinforcing material, a series of three-dimensional (3D) SiCw@C composite aerogels doped with different metal ions (Fe, Ni, Al) were designed and studied for lightweight and effective EMW absorption. The emergence of metal ions and three-dimensional conductive carbon networks enriches the loss mechanism of the composites. The results show that the SiCw@C-Al exhibits a considerable minimum reflection loss (RLmin) value at 1.5 mm thickness (-28.7 dB) and a broad effective absorption bandwidth (EAB, RL < -10 dB) of 4.1 GHz. Meanwhile, SiCw@C-Fe has good wave absorption performance at a thickness of 2 mm, RLmin is −49.2 dB, and EAB is 3.6 GHz. By adjusting the matching thickness of the Al3+ and Fe3+ crosslinked composite aerogel from 1.5 mm to 3.5 mm, the integrated EAB can cover the Ku-band, X-band and even C-band. The SA derived 3D SiCw@C composite aerogels open a new path for the design of lightweight and effective EMW absorption materials used in multi-frequency.

A topological nodal line semi-metal with a negative Poisson's ratio in a three-dimensional carbon network with sp2 hybridization.

In carbon allotropes, a series of topological semi-metals have been predicted, but both novel electronic properties and mechanical characteristics, e.g., a negative Poisson's ratio (NPR), are rarely discovered in the same sp2 type system. Here, a new three-dimensional carbon network, named WZGN, constructed from distorted one-dimensional zigzag graphene nanoribbons is proposed. The stability of the system is fully ensured by the phonon dispersion, AIMD simulation, and binding energy calculations. Besides, it is found that the system holds both topologically protected nodal line semi-metal properties together with an NPR property. Especially, the value of the NPR can exceed -0.36 when 21% uniaxial tensile strain along the c'-direction is applied. Our findings point out that nodal line semi-metals can be compatible with intrinsic NPR properties in a wide strain range in carbon systems with sp2 hybridization, suggesting possible applications in mechanical and electronics fields.

A nodal flexible-surface three-dimensional carbon network with potential applications as a lithium-ion battery anode material

This study introduces a novel three-dimensional carbon network based on cyclooctatetraene (COT), featuring a rare crossbar-like topological nodal flexible-surface and potential applications in Li-ion battery anodes.

Controllable construction of a 3D-honeycomb-like porous carbon network as a high-performance cathode for promoting Zn-ion storage capability.

Inheriting the energy storage mechanism of supercapacitors and rechargeable ion batteries, zinc ion capacitors (ZICs) greatly increase their energy density at high power without sacrificing their life span. However, sluggish kinetics and insufficient active sites for Zn2+ storage induced by the significant mismatch of charge carriers with limited pore size hinder the efficient Zn2+ storage and smooth application of carbonaceous cathode materials. Herein, a three-dimensional honeycomb-like porous carbon network (HPCN) was fabricated, which can reduce the diffusion barrier for fast kinetics, produce a high-density defect area, effectively increase active sites for charge storage, and generate a high nitrogen-doping content. Benefiting from these advantages, the optimized ZICs bring out a marvelous energy/power density (130 W h kg-1/11.7 kW kg-1) with an ultrahigh reliable cyclability of 97.8% after 50 000 cycles at a high current density of 5 A g-1. Importantly, systematic ex situ characterizations combined with theoretical calculations demonstrate that the outstanding Zn2+ storage capacity is attributed to the synergistic effect of physical co-adsorption of cations and reversible chemisorption. This work presents an attractive strategy for developing advanced carbon cathodes with suitable pores and accelerates the exploration of charge storage mechanisms, which may open a new avenue for practical supercapacitors.

MoP nanocrystals encapsulated in N-doped three-dimensional carbon networks for efficient hydrogen evolution electrocatalysis

An efficient HER electrocatalyst, in which MoP nanocrystals are encapsulated in N-doped carbon networks, has been prepared successfully via a hard template-assisted freeze-drying and subsequent carbonization–phosphorization process.

F127 assisted fabrication of Ge/rGO/CNTs nanocomposites with three-dimensional network structure for efficient lithium storage

To solve the volume expansion and poor electrical conductivity of germanium-based anode materials, Ge/rGO/CNTs nanocomposites with three-dimensional network structure are fabricated through the dispersion of polyethylene-polypropylene glycol (F127) and reduction of hydrogen. An interesting phenomenon is discovered that F127 can break GeO2 polycrystalline microparticles into 100 nm nanoparticles by only physical interaction, which promotes the uniform dispersion of GeO2 in a carbon network structure composed of graphene (rGO) and carbon nanotubes (CNTs). As evaluated as anode material of Lithium-ion batteries, Ge/rGO/CNTs nanocomposites exhibit excellent lithium storage performance. The initial specific capacity is high to 1549.7 mAh/g at 0.2 A/g, and the reversible capacity still retains 972.4 mAh/g after 100 cycles. The improved lithium storage performance is attributed to that Ge nanoparticles can effectively slow down the volume expansion during charge and discharge processes, and three-dimensional carbon networks can improve electrical conductivity and accelerate lithium-ion transfer of anode materials.

Coconut shell waste-derived graphene oxide composite with neodymium oxide (Nd2O3) for advanced applications

This paper reports the synthesis and physical properties of graphene oxide/neodymium oxide (GO/Nd2O3) composites. The GO/Nd2O3 composite was prepared by a simple Sonochemical Method, and graphene oxide was synthesized by a modified hummers method. The synthesized composites were characterized by using X-Ray Diffraction (XRD), Fourier Transform Infra-Red (FT-IR), Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX), Raman Spectroscopy, and UV–Vis Spectroscopy. The XRD data confirmed that the GO/Nd2O3 composite had a hexagonal phase structure and showed that the more Nd2O3 nanoparticles were added to GO, the more the crystallinity index increased. The FT-IR spectra showed six types of bonds of functional groups of the GO/Nd2O3 composite, namely the hydroxyl (-OH), carbonyl (C]O), (C]C), (C–O–H), (C–O–C), and the absorption band at 678 cm−1 shows REOs (Nd2O3). Raman spectroscopic analysis showed that the intensity of the ratio of ID/IG was (∼0.85) with the size of sp2 graphitic area of ∼22.6 nm. The addition of Nd2O3 particles to GO did not affect the intensity ratio of ID/IG and was almost the same for the GO and GO/Nd2O3 composite. SEM results show that the composite has a porous three-dimensional carbon network structure. The optical properties were analyzed using UV–Visible spectroscopy. The results of Urbach Energy showed that the GO/Nd2O3 composite is a semiconductor material with an Urbach Energy value of 0.050–0.063 eV, showing the potential application of GO/Nd2O3 composites in electronic devices.

Fluoride-samarium(III) doped hierarchically porous carbon nanofibers as thin separator coating layer with excellent adsorption and outstanding catalysis of lithium polysulfide for lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are promising for next-generation energy storage due to their high energy density and low cost. However, challenges such as the “shuttle effect,” slow reaction kinetics, and lithium dendrite growth hinder their performance. In this study, we developed fluoride-samarium(III) doped hierarchically porous carbon nanofibers (SmF3-PCNFs) and coated them onto separators. These three-dimensional porous carbon networks confined LiPSs, while polar SmF3 nanoparticles acted as efficient chemical anchors and catalysts. Simultaneously, the polar fluoride interfaces between the SmF3-PCNFs and cathode also can accelerate the transport of lithium ions and enhance the adhesion between them, enabling them to accommodate the huge volume changes of the sulfur cathode during cycling and improve long-cycle stability. Moreover, the modified separator with excellent lithium affinity also enables uniform lithium deposition to reduce lithium dendrite growth. Combining these advantages, the assembled Li-S battery with SmF3-PCNFs modified separator exhibits a high initial discharge specific capacity of 1068.2 mAh g−1 and retains a capacity of 655.3 mAh g−1 after 750 cycles (with a decay rate of only 0.05 % per cycle), and the Coulombic efficiency remains above 93 %. This work will pave a new design path for the preparation of modified separators in high-performance Li-S batteries.

N/O/P ternary-doped coal-based hierarchical porous carbon networks for high lithium-ion storage performance

Constructing porous structure and surface modification are effective ways to enhance the Li-ion storage performance of commercial graphite anode for lithium-ion batteries (LIBs). Herein, nitrogen, oxygen and phosphorus ternary-doped coal-based hierarchical porous carbon networks (N/O/P-CCNs) were prepared through liquid oxidation combined with self-assembly method. The N/O/P-CCNs have a three-dimensional porous carbon network structure formed by cross-linking carbon nanosheets with an appropriate specific surface area (321 m2 g−1) and distribution of micro-, meso- and macropore, while the surfaces of carbon nanosheets are doped with nitrogen, oxygen and phosphorus. Due to unique hierarchical porous structure and the synergistic effect of ternary doping, the N/O/P-CCNs anode exhibits excellent Li-ion storage properties with initial reversible capacity of 1079 mAh g−1, which is much higher than that of coal-based graphite anode (382 mAh g−1). Besides, the N/O/P-CCNs anode also has superior rate capability (336 and 275 mAh g−1 at 1.0 and 2.0 A g−1) and cycle stability with a high capacity retention (near 100 % after 100 cycles). The excellent electrochemical performance is not only related to the hierarchical pore structure that can provide efficient channels for lithium-ion transport, but also to the ternary-doping of nitrogen, oxygen and phosphorus that can provide more active sites for lithium-ion storage and enhance conductivity. This work provides a novel and effective design strategy for developing high-performance anode materials for LIBs.

F127/PDA dual-assisted fabricating high dispersed Ge nanoparticles /N-doped porous carbon composites with efficient lithium storage

Nanocrystallization and carbon composite are effective methods to solve the mechanical instability and low conductivity of Ge-based anode materials. In this work, a meaningful phenomenon is discovered that F127 can effectively disperse GeO2 polycrystalline particles, which facilitates the formation of Ge nanoparticles embedded in N-doped carbon (Ge/N-C) composites. Polydopamine (PDA) has cross-linking effect, effectively alleviating the reaggregation of GeO2 nanoparticles, and its derived N-doped carbon ensures the uniform dispersion and independent structure of Ge nanoparticles. When assessed as anode material for lithium-ion batteries (LIBs), Ge/N-C composites exhibit a high discharge capacity of 1323 mA h g−1 in the second cycle at 0.2 A g−1 and 981 mA h g−1 after 100 cycles, with a capacity retention rate of 74%. Additionally, the composites show high-rate capability of 959 mA h g−1 at 2 A g−1. The excellent lithium storage performance is attributed to that the synergistic effect between three-dimensional carbon network structure and Ge nanoparticles, which provides stable mechanical structure and abundant redox sites, suppressing volume expansion and accelerating the electrochemical reaction kinetics.

Three-Dimensional Carbon Networks Decorated with Co Nanocatalysts as Multifunctional Interlayers for a High-Performance Lithium–Sulfur Battery

Three-Dimensional Carbon Networks Decorated with Co Nanocatalysts as Multifunctional Interlayers for a High-Performance Lithium–Sulfur Battery

Design of multifunctional graphene oxide-modified nanofiber film with heterostructure (ZnS-CoS@GO@CNFs) for long-term stable potassium ion storage

When transition metal sulfides are used as high-theoretical-capacity anodes for potassium ion batteries (PIBs), their low conductivity and large volume expansion resulted in inferior rate performance and cyclic stability. In this study, multifunctional graphene oxide (GO) was employed to control the diameter and distribution of nanoparticles within composite fibers, which improved their conductivity and tensile deformation. In addition, a three-dimensional conductive carbon network composed of heterostructures and GO (ZnS-CoS@GO@CNFs) accelerated the kinetics and stabilized potassium ion storage. As the anode material of PIBs, the composite provided an excellent rate performance of 210 mA h g−1 at 3 A g−1, and after 2800 cycles under a large current of 2 A g−1, the capacity retention rate was 97.7% (171 mA h g−1). Furthermore, when the nanofiber film was used as a self-supporting anode, it maintained a stable capacity output (302 mA h g−1 after 100 cycles at 0.1 A g−1). A foldable pouch cell was assembled using a potassium ion hybrid super-capacitor, and it was found to operate safely and normally under multiangle repeated bending and final recovery; further, it provided a high energy density (134 W h kg−1) and power density (5815 W kg−1). The excellent electrochemical properties determined here further reveal the application prospects of multifunctional GO composite fiber film.

High nitrogen-oxygen dual-doped three-dimensional hierarchical porous carbon network derived from Eriocheir sinensis for advanced supercapacitors

High nitrogen-oxygen dual-doped three-dimensional hierarchical porous carbon network derived from Eriocheir sinensis for advanced supercapacitors

Self-intercalated quasi-2D structured V5Se8 wrapped with multi-walled carbon nanotubes toward advanced sodium ion batteries

Sodium-ion batteries (SIBs) have attracted much focus as electrochemical energy storage devices with unlimited potential for upcoming large-scale energy storage applications. Nevertheless, sodium ions with large radius and high mass can hinder sodium ions from diffusing into the electrode material, resulting in poor energy/power density and cycling stability. Therefore, a highly conductive three-dimensional carbon network composed of V5Se8 with a self-intercalated layer structure and one-dimensional multi-walled carbon nanotubes (MWCNTs) has been prepared using a straightforward one-step selenization process. This three-dimensional structure can increase the reversible sodium ion storage capacity and structural stability during the cycling process. The obtained V5Se8/MWCNTs electrodes have outstanding rate capacity (250 mAh g−1 at 10 A g−1) and tremendous initial reversible capacity (353 mAh g−1 at 0.2 A g−1). After 1000 cycles, they also obtain adequate cycling stability (323 mAh g−1 at 2 A g−1). The reaction mechanism of V5Se8/MWCNTs electrode in SIBs has been studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM) methods, demonstrating that this electrode experiences a reversible phase transition between V5Se8 and V throughout the Na + insertion/extraction procedures. The full cell can offer a discharge plateau of 2.02 V when coupled with a Na3V2(PO4)2F3@reduced graphene oxide cathode. It also has an excellent discharge capacity of 177 mAh g−1 at 0.1 A g−1 and good cycling stability of 79 mAh g−1 after 1000 cycles at 1 A g−1.

Heterointerface construction for permalloy microparticles through the surface modification of bilayer metallic organic frameworks: Toward microwave absorption enhancement

Reasonable heterointerface modification can effectively regulate and enhance the microwave absorption of electromagnetic materials. The surface of magnetic permalloy (PM) microparticles is modified herein by coating double-layer metal organic frameworks (MOF), which are composed of a 2-methylimidazole cobalt salt (ZIF-67) layer and a 2-methylimidazole zinc salt (ZIF-8) layer. A stable heterointerface structure with cobalt/carbon (Co/C) and zinc/carbon (Zn/C) layers is formed on the surface of PM microparticles after pyrolysis. These particles include two types of composite particles of PM solely encapsulated by ZIF-67 or ZIF-8, PM@ZIF67 and PM@ZIF8, respectively, and two types of composite PM particles with a double-layered MOF outer shell structure obtained by exchanging the coating sequence (PM@ZIF8@ZIF67 and PM@ZIF67@ZIF8). Furthermore, the thermal decomposition temperature has a significant impact on the surface morphology and magnetic properties of the composite particles. After pyrolyzing at 500 °C, the PM@ZIF67@ZIF8 samples exhibit the highest microwave absorption performance among these samples. Specifically, the minimum reflection loss and effective absorption bandwidth of PM@ZIF67@ZIF8 after pyrolyzing at 500 °C can reach −47.3 dB at a matching thickness of 3.8 mm and 5.3 GHz at a matching thickness of 2.5 mm, respectively. A heterointerface with an electrical field orientation is created in the PM@ZIF67@ZIF8 particles, which effectively enhances the interface polarization and dipole polarization. Furthermore, the formation of a three-dimensional carbon network after pyrolysis is also useful for optimizing impedance matching and enhancing magneto-electric synergism.

Multilevel spatial confinement of transition metal selenides porous microcubes for efficient and stable potassium storage

Recently, potassium-ion batteries (PIBs) have been considered as one of the most promising energy storage systems; however, the slow kinetics and large volume variation induced by the large radius of potassium ions (K+) during chemical reactions lead to inferior structural stability and weak electrochemical activity for most potassium storage anodes. Herein, a multilevel space confinement strategy is proposed for developing zinc-cobalt bimetallic selenide (ZnSe/Co0.85Se@NC@C@rGO) as high-efficient anodes for PIBs by in-situ carbonizing and subsequently selenizing the resorcinol–formaldehyde (RF)-coated zeolitic imidazolate framework-8/zeolitic imidazolate framework-67 (ZIF-8/ZIF-67) encapsulated into 2D graphene. The highly porous carbon microcubes derived from ZIF-8/ZIF-67 and carbon shell arising from RF provide rich channels for ion/electron transfer, present a rigid skeleton to ensure the structural stability, offer space for accommodating the volume change, and minimize the agglomeration of active material during the insertion/extraction of large-radius K+. In addition, the three-dimensional (3D) carbon network composed of graphene and RF-derived carbon-coated microcubes accelerates the electron/ion transfer rate and improves the electrochemical reaction kinetics of the material. As a result, the as-synthesized ZnSe/Co0.85Se@NC@C@rGO as the anode of PIBs possesses the excellent rate capability of 203.9 mA h g−1 at 5 A g−1 and brilliant long-term cycling performance of 234 mA h g−1 after 2,000 cycles at 2 A g−1. Ex-situ X-ray diffraction (Ex-situ XRD) diffraction reveals that the intercalation/de-intercalation of K+ proceeds through the conversion-alloying reaction. The proposed strategy based on the spatial confinement engineering is highly effective to construct high-performance anodes for PIBs.