Three-dimensional Interconnected Carbon Research Articles

Ultrasensitive electrochemical sensing platform based on Zr-based MOF embellished single-wall carbon nanotube networks for trace analysis of methyl parathion

In this work, a novel electrochemical sensor was designed based on Zr-based metal–organic framework (UIO-66) nanoparticles embellished single-wall carbon nanotube networks (SCN) for the detection of methyl parathion (MP). The synergistic combination of SCN and UIO-66 nanoparticles could fully exert each advantage to boost the MP electrochemical sensing analysis performance. SCN with one-dimensional hollow nanostructures formed three-dimensional interconnected carbon conductive networks, which possessed excellent conductive properties and acceptable specific surface area, enabling efficient transport of electrons and ions. UIO-66 nanoparticles with Zr-OH groups contributes and porous structure to the good affinity for phosphate groups on MP molecules, which enhanced the selective recognition and enrichment capability of sensing electrode towards MP. Under the multifunctional integration of SCN and UIO-66 nanoparticles, the SCN@UIO-66/GCE sensor could present satisfactory MP electrochemical detection performance (LOD: 8.05 nM, linear MP concentration range: 0.01–10 μM). The satisfactory practical property was realized at the SCN@UIO-66/GCE sensor with satisfactory recovery rates of 98.28–101.95 % and low RSD of 1.23–3.01 % for the electrochemical detection of MP in orange juice and lettuce samples.

Chemical-free fabrication of carbon fiber aerogels from egg boxes for the removal of pharmaceutically active compounds in aqueous solution

The presence of pharmaceuticals and personal care products (PPCPs) in aquatic environments extremely concerns to human health and the ecosystem; thus, their removal is essential. This work produced carbon fiber aerogels from egg box waste using a chemical-free fabrication process. The pyrolyzed egg box aerogel (PEBA) exhibited three-dimensional interconnected carbon nanofibers with high surface area and pore volume. The adsorption capacity and removal efficiency of four PPCPs, namely, diclofenac (DIC), caffeine (CF), tetracycline (TC), and ciprofloxacin (CIP), from water were high and comparable to other carbon-based adsorbents, and the adsorption time was much faster (within 20 min). The Redlich-Peterson and the pseudo-second-order models were the best-fitted isotherm and kinetic models, respectively, which imply multilayer adsorption at high concentrations and the chemisorption process. Furthermore, mechanisms responsible for the adsorption of all PPCPs were elucidated. PEBA was applied in the fixed-bed column experiment to mimic the continuous adsorption process. In addition, PEBA was recyclable after low-temperature heat treatment. The adsorption capacity (8.1 mg/g) and removal efficiency (94.03 %) for TC was still high after three cycles. Metabolomics analysis revealed that no secondary pollution is released into water after thermal treatment. Therefore, PEBA has the potential as an efficient adsorbent for removing PPCPs from water.

Facile fabrication of Zr-based metal–organic framework/Ketjen black-carbon nanotubes composite sensor for highly sensitive detection of methyl parathion

A novel methyl parathion (MP) electrochemical sensor was fabricated from the multifunctional composite of Zr-based metal–organic framework (UiO-66) and Ketjen black-carbon nanotubes (KB-CNTs), which achieved the sensitive detection of MP in food samples. For the UiO-66/KB-CNTs composite, Zr-based UiO-66 with Zr-OH groups possessed good affinity for phosphate groups on methyl parathion molecules, which enhanced the selective recognition and enrichment capability towards MP, and KB-CNTs possessed three-dimensional interconnected carbon conductive network with synergistic point-line carbon conductive contact, which showed excellent electrical conductivity. Moreover, KB with pearl chain-like structure and more conductive contact points realized the full contact between KB-CNTs and UiO-66 with Zr-OH groups. The fabricated UiO-66/KB-CNTs/GCE sensor showed good MP detection performance with low limit of detection of 1.53 nM in linear MP concentration range of 0.005–12 µM. Moreover, the fabricated sensor showed good repeatability, reproducibility, and selectivity. A good practical feasibility can be achieved at the UiO-66/KB-CNTs/GCE sensor for the detection of MP in grape juice and apple juice samples (Recovery rate: 96.14–102.93, relative standard deviation: 2.17%-4.95%).

Interfacial engineered PANI/carbon nanotube electrode for 1.8 V ultrahigh voltage aqueous supercapacitors

Flexible three-dimensional interconnected carbon nanotubes on the carbon cloth (3D-CNTs/CC) were obtained through simple magnesium reduction reactions. According to the Nernst equation, the cell voltage based on these pure carbon electrodes without any additives could reach 1.5 V due to the higher di-hydrogen evolution over potential in neutral 3.5 M LiCl electrolytes. In order to improve the electrochemical performance of the electrodes, 3D-CNTs/CC electrodes covered with polyaniline barrier layer (3D-PANI/CNTs/CC) were prepared by in situ electropolymerization using interfacial engineering method. The assembled symmetric supercapacitors display a broadened voltage of 1.8 V, high areal capacitance of 380 mF cm−2, outstanding areal energy density of 85.5 μWh cm−2 and 84% of its initial capacitance after 20 000 charge-discharge cycles. This work demonstrated that the interface engineering strategy provides a promising way to improve the energy density of carbon-based aqueous supercapacitors by widening the voltage and boosting the capacitance simultaneously.

Interfacial engineering of heterostructured Mo2C-Ru nanoparticles dispersed on 3D interconnected carbon nanobelts for highly efficient hydrogen evolution

Hydrogen produced by electrochemical water splitting depends on the development of highly efficient electrocatalysts. In this study, we report the design and synthesis of a robust hydrogen evolution reaction (HER) electrocatalyst Mo2C-Ru@CNBs, which is consisted of heterostructured Mo2C-Ru nanoparticles that dispersed on three-dimensional interconnected carbon nanobelts (CNBs). Benefiting from the high intrinsic catalytic activity of Mo2C-Ru heterostructure, abundant catalytic active sites and facilitated mass transfer, the Mo2C-Ru@CNBs catalyst shows high HER catalytic activity with ultralow overpotentials of 17 and 18 mV at 10 mA cm−2 in acidic and alkaline media, respectively, which are superior to the individual components of Mo2C@CNBs and Ru@CNBs catalysts, commercial 20% Pt/C and the recently reported Mo- and Ru-based electrocatalysts. Density functional theory calculations reveal the extensive electronic interaction between Mo2C and Ru at the heterointerfaces, leading to well-modulated electronic structure for optimized intrinsic catalytic activity and enhanced electrical conductivity.

KVPO4F/carbon nanocomposite with highly accessible active sites and robust chemical bonds for advanced potassium-ion batteries

KVPO4F (KVPF) has been extensively investigated as the potential cathode material for potassium-ion batteries (PIBs) owing to its high theoretical capacity, superior operating voltage, and three-dimensional K+ conduction pathway. Nevertheless, the electrochemical behavior of KVPF is limited by the inherent poor electronic conductivity of the phosphate framework and unstable electrode/electrolyte interface. To address the above issues, this work proposes an infiltration-calcination method to confine the in-situ grown KVPF into the mesoporous carbon CMK-3 (denoted KVPF@CMK-3). The assembled KVPF@CMK-3 nanocomposite features three-dimensional interconnected carbon channels, which not only offer abundant active sites and significantly accelerate K+/electron transport, but also prevent the growth of KVPF nanoparticle agglomerates, hence stabilizing the structure of the material. Additionally, V–F–C bonds are created at the interface of KVPF and CMK-3, which reduce the loss of F and stabilize the electrode interface. Thus, when tested as a cathode material for PIBs, the KVPF@CMK-3 nanocomposite delivers superior reversible capacitiy (103.2 mAh g−1 at 0.2 C), outstanding rate performance (90.1 mAh g−1 at 20 C), and steady cycling performance (92.2 mAh g−1 at 10 C and with the retention of 88.2% after 500 cycles). Moreover, its potassium storage mechanism is further examined by ex-situ XRD and ex-situ XPS techniques. The above synthetic strategy demonstrates the potential of KVPF@CMK-3 to be applied as the cathode for PIBs.

Abundant (110) Facets on PdCu3 Alloy Promote Electrochemical Conversion of CO2 to CO.

Electrochemical conversion of CO2 to high-value chemical fuels offers a promising strategy for managing the global carbon balance but faces huge challenges due to the lack of effective electrocatalysts. Here, we reported PdCu3 alloy nanoparticles with abundant exposed (110) facets supported on N-doped three-dimensional interconnected carbon frameworks (PdCu3/NC) as an efficient and durable electrocatalyst for electrochemical CO2 reduction to CO. The catalyst exhibits extremely high intrinsic CO2 reduction selectivity for CO production with a Faraday efficiency of nearly 100% at a mild potential of -0.5 V. Moreover, a rechargeable high-performance Zn-CO2 battery with PdCu3/NC as a cathode is developed to deliver a record-high energy efficiency of 99.2% at 0.5 mA cm-2 and rechargeable stability of up to 133 h. Theoretical calculations elucidate that the exposed (110) facet over PdCu3/NC is the active center for CO2 activation and rapid formation of the key *COOH intermediate.

Bimetallic sulfides SnS/FeS particles anchored on tremella-like carbon as advanced anode material for sodium ion storage

Sodium-ion batteries (SIBs) are considered as the most promising alternatives to lithium-ion batteries (LIBs). The design of electrode materials is crucial to the improvement of the electrochemical performance of SIBs. In this work, the multicomponent sulfides SnS@FeS particles anchored on tremella-like carbon (SnS@FeS/C) are rationally engineered and constructed. The bimetallic sulfides SnS@FeS particles can provide abundant redox active sites and distinguished electronic structures. Simultaneously, the three-dimensional interconnected carbon with tremella-like structure mitigates the volume expansion and enhances the conductivity. Benefiting from the compositional and structural advantages, the SnS@FeS/C composite achieves high reversible capacity (410.1 mAh g−1 at 100 mA g−1) and excellent rate capability (300.7 mAh g−1 at 3000 mA g−1) in SIBs. Notably, it also exhibits ultralong cycling performance (360 mAh g−1 after 1000 cycles). Additionally, the kinetic analyses of redox reaction reveal that the pseudo-capacitance behavior dominates the charge/discharge process of SnS@FeS/C electrode. This work provides a strategy for preparation of multicomponent metal sulfides with three-dimensional carbon network for excellent electrochemical performance, paving the way for the potential applications in energy storage fields.

Achieving Cycling Durability of Lithium-Sulfur Batteries via Capturing Polysulfides through a Three-Dimensional Interconnected Carbon Network Anchored with Ultrafine FeS Nanoparticles.

Shuttle effect has always been a critical obstacle to the application of lithium-sulfur (Li-S) batteries for leading to unstable cycle performance and a short lifespan. To solve this problem, a particular strategy is put up to relieve shuttle effect by capturing soluble polysulfides through a three-dimensional interconnected carbon network. Due to the uniformly anchored ultrafine FeS nanoparticles on a 3D interconnected carbon network, the material could lock soluble polysulfides on the cathode side and promote electrochemical conversion reactions among sulfur species. By optimizing the active site exposure of FeS and designing a hierarchical porous and multichannel structure to ensure rapid migration of ions and electrons at the same time, the interlayer can effectively suppress the shuttle effect and enhance sulfur utilization. Thus, the Li-S battery presents excellent cycling stability and rate capability, namely, a reversible specific capacity of 560 mAh g-1 at 2.0 C over 500 cycles with a decay rate of 0.012% per cycle and a specific capacity of 597 mAh g-1 at a 5.0 C current rate. This study offers a promising strategy for designing the structure of an interlayer to achieve long-cycle stable Li-S batteries.

Necklace-like ferroferric oxide (Fe3O4) nanoparticle/carbon nanofibril aerogels with enhanced lithium storage by carbonization of ferric alginate

Theoretically, transition metal oxide/carbon nanofibril aerogels are promising candidates for lithium-ion battery anode materials as they combine the high stability and electrical conductivity of the carbon matrix and the high theoretical specific capacity of transition metal oxide (TMO). However, challenges still exist to embed TMO nanoparticles into thin carbon nanofibril absolutely and tightly, limiting further improvements in electrochemical performances of the composites. Herein, necklace-like Fe3O4/carbon nanofibril aerogel (Fe3O4/CNF) was constructed by crosslinking alginate with Fe3+, followed by carbonization of the obtained ferric alginate aerogel. Based on an “egg-box” helical structure resulting from strong coordination between the Fe3+ and the carboxylate groups of alginate, three-dimensional interconnected carbon aerogel was facilely fabricated with Fe3O4 nanoparticles (~11 nm in diameter) firmly embedded in ultrafine carbon nanofibrils (~18 nm in diameter), exhibiting a special necklace-like structure. Consequently, the composite exhibits a high reversible capacity and stability of 1176 mAh g−1 over 200 cycles at 1 A g−1 and a high rate performance of 615 mAh g−1 at 4 A g−1. These Fe3O4/CNF aerogels may have potential applications for enhanced lithium storage of electrochemical devices.

Hard-template synthesis of three-dimensional interconnected carbon networks: Rational design, hybridization and energy-related applications

Abstract Three-dimensional interconnected carbon networks (3DCNs) materials have the advantages of large specific surface area, high porosity, and high electronic and ionic conductivity. Especially, 3DCNs can combine with other nanomaterials to achieve the synergistic effect in numerous applications, such as energy storage, catalysis, and structural engineering. For the synthesis of 3DCNs, the hard template strategy is the most popular method due to its efficient and versatile process and controllable production. This paper summarized the recent progress in the approaches to constructing 3DCNs by using hard templates including metals, inorganic non-metals, etc. The composites based on 3DCNs with multi-dimensional reinforcements, such as 0D nanoparticles, 1D nanotubes/nanofibers, and 2D nanosheets are introduced. The applications of these 3DCNs composites towards energy storage and conversion devices are reviewed. Furthermore, the challenges on the hard-templated 3DCNs are discussed based on the current progress.

Linear-Polyethyleneimine-Templated Synthesis of N-Doped Carbon Nanonet Flakes for High-performance Supercapacitor Electrodes.

Novel N-doped carbon nanonet flakes (NCNFs), consisting of three-dimensional interconnected carbon nanotube and penetrable mesopore channels were synthesized in the assistance of a hybrid catalytic template of silica-coated-linear polyethyleneimine (PEI). Resorcinol-formaldehyde resin and melamine were used as precursors for carbon and nitrogen, respectively, which were spontaneously formed on the silica-coated-PEI template and then annealed at 700 °C in a N2 atmosphere to be transformed into the hierarchical 3D N-doped carbon nanonetworks. The obtained NCNFs possess high surface area (946 m2 g−1), uniform pore size (2–5 nm), and excellent electron and ion conductivity, which were quite beneficial for electrochemical double-layered supercapacitors (EDLSs). The supercapacitor synthesized from NCNFs electrodes exhibited both extremely high capacitance (up to 613 F g−1 at 1 A g−1) and excellent long-term capacitance retention performance (96% capacitive retention after 20,000 cycles), which established the current processing among the most competitive strategies for the synthesis of high performance supercapacitors.

Synthesis of a three-dimensional interconnected carbon nanorod aerogel from wax gourd for amperometric sensing.

The authors describe a method for synthesis of a three-dimensional (3D) interconnected carbon nanorod aerogel (3D-ICNA) starting from wax gourd (Benincasa hispida) which is a low-cost biomass. The 3D-ICNA possesses unique 3D interconnected and porous nanostructure, with abundant edge-plane-like defective sites, a large specific surface area (823m2g-1) and a large pore volume (0.12cm3g-1). This makes the material attractive in terms of electrochemical sensing. To validate the feasibility, the voltammetric response towards ferricyanide, hydrogen peroxide (H2O2), acetaminophen, ascorbic acid (AA), dopamine, uric acid and epinephrine was investigated by using a glassy carbon electrode (GCE) modified with 3D-ICNA. The modified GCE shows higher electron-transfer capacity than a conventional GCE. In addition, as an electrochemical sensor for AA or H2O2, the electrode exhibits better analytical performance with lower detection limit [3.5μM for AA or 0.68μM for H2O2 based on 3σ/m criterion (where σ is the standard deviation of the blank and m is the slope of the calibration plot)], wider linear range and higher sensitivity (0.14, 0.11 and 0.080μAμM-1cm-2 for AA or 0.24 and 0.20μAμM-1cm-2 for H2O2) compared to a plain GCE or a carbon nanotube-modified GCE. The modified GCE exhibits a large potential for the amperometric determination of AA or H2O2 in real samples. Graphical abstract By employing the biomass of wax gourd (Benincasa hispida) as the precursor, a three-dimensional interconnected carbon nanorod aerogel was prepared. It is shown to be a viable material for the construction of an advanced electrochemical sensor for H2O2 and ascorbic acid.

Compared investigation of carbon-decorated Na3V2(PO4)3 with saccharides of different molecular weights as cathode of sodium ion batteries

A critical issue to boost the development of sodium ion batteries is the development of advanced active materials via meticulous understanding of the synthesis process. The practical application of sodium vanadium phosphate (Na3V2(PO4)3), which shows high energy density, stable structure and excellent thermal properties, is hindered by the intrinsic poor electronic conductivity. Carbon coating was proved to be an effective strategy to cover such pristine limitation and deserved systematic and intensive investigation. Herein, saccharides that widely distributed in nature with different molecular weights were selected to identify the function mechanism of carbon sources in preparing Na3V2(PO4)3@C composite via solid state reaction. Comprehensive and systematic results evidenced that the high polymer starch with glucose polymerization could construct three-dimensional interconnected carbon network, which would boost the electron conductivity and stabilize the structure upon repeated sodium ions insertion/extraction. As a consequence, the extraordinary high rate capability and long-time stability were obtained: a high rate capacity of 72 mA h g−1 could be delivered even at 40 C and the cell retained a capacity retention of 82.8% after 1000 cycles at 1 C. We believe that our work presents here would provide important insights into the carbon coating strategy, which will be favourable for accelerating the commercialization of SIBs.

Ni-polymer gels-derived hollow NiSb alloy confined in 3D interconnected carbon as superior sodium-ion battery anode

Antimony is being extensively investigated as anode material for sodium ion batteries (SIBs) due to its appropriate sodium insertion potentials, flat charge-discharge plateau and high sodium storage capacity. However, it suffers from unsatisfied cycling stability originated from the huge volume change during cycling. Herein, hollow NiSb spheres confined by three-dimensional interconnected carbon matrix (NiSb⊂3DCM) are prepared by a cross-linking reaction between Ni2+ and alginate and a galvanic replacement reaction. Benefiting from its the hollow, porous structure and mechanical buffer provided by Ni and carbon coating, NiSb⊂3DCM electrode can deliver a stable capacity of 366 mAh g−1 with 94.3% capacity retention rate after 400 cycles operated at 1 A g−1, which is the best cycling performance reported so far for Sb-based alloy anodes.

Direct planting of ultrafine MoO2+δ nanoparticles in carbon nanofibers by electrospinning: self-supported mats as binder-free and long-life anodes for lithium-ion batteries

Three-dimensional (3D) interconnected carbon nanofibrous mats containing well-dispersed MoO2+δ nanocrystals are fabricated through a facile electrospinning route followed by thermal treatment in N2. The resulting nanostructured monolithic hybrid mat made of C/MoO2+δ nanofibers exhibits superior Li-storage performances, when evaluated as a free-standing anode material. At a current density of 200 mA g(-1), a reversible capacity as high as 876.9 mA h g(-1) is achieved after 250 cycles. A capacity of 447.9 mA h g(-1) could still be maintained after 1000 cycles even at a high current density of 2000 mA g(-1), indicating high rate capability and cyclability. The attractive electrochemical performances of the as-obtained 3D C/MoO2+δ networks may benefit from the synergistic effects of the unique nanoarchitectures and the integrity of the electrodes. Monodispersed MoO2+δ nanocrystals encapsulated in carbon nanofibers not only provide interfacial storage but also improve the transport kinetics of electrons and lithium ions.

Unusual semimetallic behavior of carbonized ion-implanted polymers

We report a comprehensive charge transport study of ion-implanted rigid rod and ladder polymers $p$-phenylenebenzobisoxazole, $p$-phenylenebenzobisthiazole, and benzimidazobenzophenanthroline. The three pristine materials are strong and stable polymers with a room temperature conductivity ${\ensuremath{\sigma}}_{\mathrm{RT}}\ensuremath{\sim}{10}^{\ensuremath{-}12}$ S/cm. After high dosage ion implantation using ${\mathrm{Kr}}^{+},$ a carbonized and conducting layer forms on the surface of the film samples with ${\ensuremath{\sigma}}_{\mathrm{RT}}>{10}^{2}$ S/cm. The experimental results suggest that this carbonized layer is semimetallic with unusual properties. The observed dc conductivity follows $\ensuremath{\sigma}(T)={\ensuremath{\sigma}}_{0}+\ensuremath{\Delta}\ensuremath{\sigma}(T),$ where $\ensuremath{\Delta}\ensuremath{\sigma}(T)$ is weakly temperature dependent and interpreted within the model of weak localization and electron-electron interaction effects. The model reveals that the interaction effect is three dimensional for the experimental temperature range (3--300 K), whereas the weak localization effect undergoes a dimensional crossover at \ensuremath{\sim}60 K from three to two-dimensions with decreasing temperature. The magnetoconductance, thermoelectric power, and microwave dielectric constant results are all in agreement with this semimetallic model. In addition, all these results consistently point to an enhanced interaction effect at low temperatures due to the reduced dimensionality of the localization effect. It is concluded that a ${\mathrm{sp}}^{2}$ rich and three-dimensional interconnected carbon network reformed upon ion implantation of the densely packed pristine polymers is responsible for the semimetallic behavior.