Simple Chemical Vapor Deposition Research Articles

Construction of a highly ordered SiC nanofiber@C fiber heterojunction hybrid with a fuzzy grass-like structure for enhanced microwave absorbing performance

Carbon fibers (Cf) materials with excellent dielectric loss are increasingly attracting attention in the field of microwave absorption. However, the inherent high conductivity of carbon materials usually causes impedance mismatch, which seriously limits their widespread applications in the field of electromagnetic wave (EMW) absorption. To solve this problem, a highly ordered SiC nanofiber@C fiber (SiCnf@Cf) heterojunction hybrid with a fuzzy grass-like structure was fabricated through a simple chemical vapor deposition (CVD) method. Providing a heterogeneous interface on the surface of carbon fibers not only improves their impedance matching capability but also enhances their interfacial loss capability. As a result, a minimum reflection loss (RLmin) for SiCnf@Cf heterojunction hybrid is −44.04 dB at 13.6 GHz with a thickness of 1.2 mm, and a maximum effective absorption bandwidth (EABmax) is 3.44 GHz with a thin thickness of 1.1 mm. Furthermore, it also exhibits outstanding thermal insulation performance, which make it a potential candidate for heat-insulating applications. And due to its lightweight and soft characteristics, it perfectly meets the needs of wearable flexible absorbing materials. Therefore, this study not only provides a straightforward for preparing EMW-absorbing materials with exceptional performance, but also offers a solution for improving the thermal stability of the carbon-based material.

Highly textured AlN film synthesized on a graphene-like undercoating

Piezoelectric properties of polycrystalline AlN films are strongly dependent on the texture of the material. For a number of applications, such as microelectromechanical systems (MEMS) and acoustic resonators, it is important to have a well-defined (002) orientation of the crystallites. Using an original method of selective deposition of graphene-like films (GLFs) followed by a simple, safe and efficient chemical vapor deposition (CVD) of AlN, we clearly demonstrate that the GLF sublayer does enhance the texture quality of AlN columnar structures. The improved crystal orientation along the (002) direction for AlN film grown on GLFs is locally visualized using a scanning electron microscope (SEM) and quantitatively reinforced using Raman spectroscopy.

One-step fabrication of P-Co5.47N/Co9S8@NPC heterojunction derived from saccharomycetes cerevisiae as environment-friendly bifunctional high-efficiency electrocatalysts

The one-step green preparation of heterojunction-structured bifunctional high-efficiency electrocatalysts provides a simple method for the green, low-cost, convenient and efficient application of hydrogen energy, meanwhile it is still challenging to achieve. In the present work, the phosphorus-doped two-phase heterojunction P-Co5.47N/Co9S8@NPC nanorods was synthesized on carbon cloth (CC) as a high-quality bifunctional electrode through simple one-step chemical vapor deposition (CVD) method. Saccharomycetes cerevisiae were used for the non-toxic phosphorus doping and formation of a carbon nanolayer wrapping Co5.47N/Co9S8 nanorods. Compared with the single-phase electrocatalyst Co9S8@NPC NSs/CC, P-Co5.47N/Co9S8@NPC NSs/CC exhibited more excellent electrocatalytic performance which required overpotentials of 69 mV for hydrogen evolution reaction (HER), 182.5 mV for oxygen evolution reaction (OER), 1.45 V for over water splitting (OWS) at 10 mA cm−2 in KOH solution. The designed P-Co5.47N/Co9S8@NPC NSs/CC presented multiple advantages of nanorod structure, doped structure, abundant heterointerfaces, as well as dual-phase synergy, which triggered outstanding electrocatalytic performance.

Synergistic engineering of palladium-cobalt nanoalloys on graphite sheet for efficient and sustainable hydrogen evolution reaction

The electrochemical hydrogen evolution reaction (HER)—a carbon-free route for hydrogen (H2) production—is of the utmost importance for H2-economy. Currently, HER performance is mainly restricted by the lack of promising alternatives to Pt-based electrocatalysts. In this study, we developed bimetallic PdCo alloy thin films with outstanding catalytic properties for the HER under acidic conditions. A simple aerosol-assisted chemical vapor deposition technique designed in-house was used to produce bimetallic alloy thin films on graphite sheets. The thin-film morphological patterns were significantly changed by varying the deposition time from 30 to 90 min. The optimized PdCo catalyst deposited for 30 min had a unique nanostructure with numerous active sites and exhibited faster HER kinetics than its analogs and pure Pd. As-prepared PdCo-30 electrode produced current densities of 10 and 1000 mA cm−2 at overpotentials of 41 and 161 mV, respectively, along with a Tafel slope of 42 mV/dec, high conductivity (0.28 Ω), and catalytic stability of ∼24 h in 0.5 M H2SO4. The excellent HER activity of the PdCo alloy was attributed to the synergy between the noble transition metal and the thin nanostructured layer of the bimetallic catalyst, which promoted formation of extensive electroactive sites on the conductive graphite surface. Density functional theory calculations confirmed the experimental findings. The Gibbs free energy (ΔGH*) of the PdCo alloy (−0.43 eV) was significantly lower than that of pure Pd (−0.57 eV), confirming the enhancement in HER activity due to the introduction of Co into the Pd lattice.

Home-made chemical vapor deposition-based synthesis of binder-free nanostructured magnesium-molybdenum-sulfide electrode materials for supercapacitor application

Molybdenum disulfides (MoS2) is considered as promising electrode materials (E-M) for high electrochemical performance (ECP) of lithium-ion batteries and supercapacitors due to their layered nanostructures. Herein, MoS2, MgS and hetrostructure MgS/MoS2 E-Ms comprising of nano-particles/sheets/needles like structures are synthesized on Nickel foam (Ni–F) by a simple home-made chemical vapor deposition (CVD) technique. The XRD analysis confirmed the formation of MoS2, MgS and MgS/MoS2 polycrystalline E-Ms growing along different directions. The FESEM analysis is confirmed that the addition of MgS layer over the surface of MoS2 change the surafce morphology from nano-particles to nano-needles. The change in structural and microstructural features is indicated the appearance of defects, micro-strain and dislocations density which are fruitful for excellent ECP. The cyclic voltammetry analysis is indicated the pseudocapacitive nature of the synthesized E-Ms. The maximum specific capacitance values for MoS2/Ni–F, MgS/Ni–F and MgS/MoS2/Ni–F E-Ms are 1273, 1688 and 3934 F/g at 1 A/g respectively. Moreover, the addition of MgS layer over MoS2/Ni–F is revealed the excellent cyclic stability of 98.76 % at current density of 10 A/g after 4000 cycles, energy density values are ranged from 79 to 136 W h/kg with homologous power density of 250–2500 W/kg and very small charge transfer resistance. The simulations of Power's Law and Dunn's model is confirmed that the excellent ECP is due to both capacitive and diffusive controlled contributions of heterostructured MgS/MoS2/Ni–F E-Ms. Additionally, MgS/MoS2/Ni–F E-Ms have both battery and pseudocapacitive nature due to unique nano-needles like morphology. The excellent electrochemical properties of MgS/MoS2/Ni–F E-Ms substantiate their potential applications in portable energy storage devices.

Hydrophobic Silk Fibroin-Agarose Composite Aerogel Fibers with Elasticity for Thermal Insulation Applications.

Aerogel fibers, characterized by their ultra-low density and ultra-low thermal conductivity, are an ideal candidate for personal thermal management as they hold the potential to effectively reduce the energy consumption of room heating and significantly contribute to energy conservation. However, most aerogel fibers have weak mechanical properties or require complex manufacturing processes. In this study, simple continuous silk fibroin-agarose composite aerogel fibers (SCAFs) were prepared by mixing agarose with silk fibroin through wet spinning and rapid gelation, followed by solvent replacement and supercritical carbon dioxide treatment. Among them, the rapid gelation of the SCAFs was achieved using agarose physical methods with heat-reversible gel properties, simplifying the preparation process. Hydrophobic silk fibroin-agarose composite aerogel fibers (HSCAFs) were prepared using a simple chemical vapor deposition (CVD) method. After CVD, the HSCAFs' gel skeletons were uniformly coated with a silica layer containing methyl groups, endowing them with outstanding radial elasticity. Moreover, the HSCAFs exhibited low density (≤0.153 g/cm3), a large specific surface area (≥254.0 m2/g), high porosity (91.1-94.7%), and excellent hydrophobicity (a water contact angle of 136.8°). More importantly, they showed excellent thermal insulation performance in low-temperature (-60 °C) or high-temperature (140 °C) environments. The designed HSCAFs may provide a new approach for the preparation of high-performance aerogel fibers for personal thermal management.

Chemical vapor deposition-based synthesis of binder-free nanostructure α-MoO3 electrode material for PES devices

Molybdenum-based metal oxides have succeeded in incredible consideration for supercapacitor applications due to their outstanding structural, morphological and electrochemical properties. Herein, a highly porous orthorhombic MoO3 (α-MoO3) nanobenzene like nanosheets are synthesized on nickel foam (Ni–F) via a simple and cost-effective chemical vapor deposition (CVD) technique. The x-ray diffraction (XRD) analysis confirmed the synthesis of nanostructured α-MoO3 having multi oriented diffraction planes. The surface morphology (SEM) analysis indicated that the entwined nanobenzene through nano-rods/particles is beneficial for good electrical conductivity hence the high electrochemical performance of synthesized α-MoO3. The electrochemical properties of synthesized α-MoO3 electrode material like cyclic voltammetry (CV), galvanostatic charging–discharging (GCD) and electrochemical impedance spectroscopy (EIS) are analyzed using a three-electrode electrochemical workstation in 2 M KOH electrolyte solution. The synthesized α-MoO3 pseudocapacitor presented a maximum specific capacitance of 3206 F g−1 at a current density of 1 A/g. Moreover, α-MoO3 exhibits a cyclic stability of about 99.95% after 3000 cycles, high energy density (111 Wh kg−1), power density (2500 W kg−1) and negligible charge transfer resistance (0.6 ohms), indicating that it can serve as an excellent electrode material for supercapacitors. The Power law and Dunn’s model simulations also confirmed that the excellent electrochemical performance of synthesized α-MoO3 electrode material is contributed by capacitive as well as diffusion-controlled behavior.

Self-Assembled BiGaSeAs Composite Superlattice-Structured Nanowire for Broad-Band Photodetection.

Photodetectors with a broad-band response range are widely used in many fields and are regarded as pivotal components of the modern miniaturized electronics industry. However, commercial broad-band photodetectors composed of traditional bulk semiconductor materials are still limited by complex preparation techniques, high costs, and a lack of mechanical strength and flexibility, which are difficult to satisfy the increasing demand for flexible and wearable optoelectronics. Therefore, researchers have been devoted to finding new strategies to obtain flexible, stable, and high-performance broad-band photodetectors. In this work, a novel self-assembled BiGaSeAs composite superlattice-structured nanowire was developed with a simple chemical vapor deposition method for easy fabrication. After the device assembling, the photodetector showed outstanding performance in terms of obvious Ion/Ioff (13.9), broad-band photoresponse (365-940 nm), excellent responsivity (1007.67 A/W), high detectivity (9.38 × 109 Jones), and rapid response (21 and 23 ms). The formation of microheterojunctions among various materials inside the nanowires also contributed to their extended broad-spectrum response and outstanding detection ability. These results indicate that the BiGaSeAs nanowires have potential applications in the field of flexible and wearable electronics.

Highly enhanced and stable field emission performance of CNT – Dielectric (Si3N4) hybrids

In the present study, vertically aligned carbon nanotubes (CNTs) were grown onto Si substrates using a simple thermal chemical vapour deposition (TCVD) technique. Subsequently, the dielectric layer of Si3N4 was coated over the pristine CNTs using the Plasma Enhanced CVD (PECVD) method. Various characterizations were carried out on the as-deposited samples to study the structural properties, surface morphology, elemental composition, and electronic structure. The field emission measurements executed on CNT – Si3N4 samples showed an enhanced current density of 8.28 mA/cm2 compared to the 2.85 mA/cm2 current density of the pristine CNTs. A detailed study reveals that, apart from the basic conventional field emission parameters, the electronic structure of the CNTs, along with the presence of disordered carbon atoms and the presence of the dielectric material, are responsible for enhancing the current density and temporal stability of the CNT – Si3N4 hybrids. The study aids in exploring CNT-dielectric hybrids for better field emission properties with improved stability for field emission applications.

Study of Ion Velocity Effect on the Band Gap of CVD-Grown Few-Layer MoS2.

The present work reports on a simple chemical vapor deposition (CVD) technique that employs alkali halide (NaCl) to synthesize high-quality few-layer MoS2 by reducing growth temperature from 850 to 650 °C, and its ion irradiation study for band gap modification. The Raman peak position difference of A1g to E12g of ≈24.5 cm-1 for the synthesized MoS2 corresponds to a few layers (<5 monolayers) of MoS2 on the substrate, as also confirmed by atomic force microscopy (AFM). The optical image shows the continuous distribution of flakes throughout the substrate and the average area of flakes ≈0.2 μm2 as confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Swift heavy-ion (SHI) irradiation at 60, 100, and 150 MeV ion energies of 1 × 1012 ions/cm2 ion fluence have been used to modify the band gap in few-layer MoS2. The ions with two different energies are chosen at two sides of the Bragg peak of energy loss curve in such a way as to have the same value of electronic energy loss (Se) but different ion energies to examine the velocity effect for the ion-induced modification. The absorbance peaks for 60 and 150 MeV irradiated samples show the same effect in the band gap modification.

Fabrication of superhydrophobic aluminum with enhanced anticorrosive property

The current work mainly introduces a facile method to obtain superhydrophobic aluminum with a hierarchical micro-nanostructure by a combination strategy of anodizing, chemical etching, and surface modification using SiO2@PDMS coating via a simple chemical vapor deposition (CVD) method. Scanning electron microscopy (SEM), energy dispersive X-ray (EDS), EDS-mapping, X-ray diffraction (XRD) and water contact angle (WCA) measurements have been performed to characterize the surface morphology, chemical composition, phase structure, and wetting property of the surfaces, respectively. The SEM results showed that by anodizing a network of cylindrical nanoporous is formed. By etching, the diameter of these pores increases and surface modification using CVD causes the deposition of SiO2@PDMS nanoparticles over them. The WCA measurements showed that the samples of the anodized and anodized-etched aluminum after modifying with SiO2@PDMS nanoparticles become superhydrophobic with values of 153° and 154°, respectively. The corrosion resistance of samples was analyzed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The results displayed that the charge transfer resistance of the superhydrophobic surface of modified anodized-etched aluminum is 16700 kΩ cm2, which is 900 times higher than that of pure aluminum. Also, the positive shift of 0.385 V in corrosion potential and reduction of more than 3 orders of magnitude in corrosion current are observed compared with aluminum. All results show a significant improvement in the corrosion protection of Al due to anodizing and surface modification with superhydrophobic coating. This method is suggested as a simple technique to creating aluminum with superhydrophobic surfaces in industry.

Microwave absorption enhancement by SiC nanowire aerogels through heat treatment-based oxidation modulation

SiC nanowire aerogels (SNWA) emerge as a promising category of electromagnetic wave absorbers (EMA) that can be applicable to extreme environments since they possess exceptional dielectric loss properties and superior ceramic characteristics. However, obtaining high-performance microwave absorption (MA) with a single SiC nanowire component poses a formidable challenge, such that the intrinsic MA potential in SNWA should be analyzed in depth. In this study, SNWAs were synthesized as a foundational matrix, of which the nanowire diameters were uniformly distributed, by adopting a straightforward and simple chemical vapor deposition (CVD) method. Subsequently, the SiO2 sheath thickness on the external surface of SiC nanowires was modified through controlled oxidation modulation. Noteworthily, the above-described precise control over the SiO2 sheath thickness served a dual purpose: it enables optimal impedance matching in the SNWA while substantially augmenting its dielectric loss capacity. To the best of our knowledge, this study has underscored the significance of optimizing the SiC/SiO2 heterointerface for enhancing MA in SNWA for the first time. Such optimization is promising to significantly facilitate the design and synthesis of SiC nanowire-based EMA.

Investigation on the Mist Intensity to Deposit Gallium Oxide Thin Films by Mist Chemical Vapor Deposition

In this study, a novel, simple, and robust mist chemical vapor deposition is demonstrated, compatible with existing industrial practices to deposit gallium oxide thin films and influence of mist intensity on the properties of gallium oxide. The intensity of the mist generation is optimized to obtain smooth and uniform thin films. The thin film deposited in this work is mixed phase polycrystalline gallium oxide. Ultraviolet–visible–near‐infrared spectroscopy and photo response of thin film unveil that gallium oxide thin film is responsive to ultraviolet wavelengths including deep ultraviolet‐C and ultraviolet‐B bands and the mist‐generation intensity has negligible influence on the bandgap of the thin film. Thickness of thin film can be altered by varying the mist intensity. It is observed that there is no appreciable impact on refractive index of varying mist intensity. Morphological studies prove the formation of ultrasmooth thin film with root mean square value of 0.628 nm; which is closer and/or better than conventional semiconductor thin‐film deposition processes used for depositing Ga2O3.

Large-scale synthesis of 3D ordered microporous carbon at low temperature using cobalt ions exchanged zeolite Y as a template

Zeolite-templated carbons (ZTCs) have a unique three-dimensional (3D) ordered microporous structure and an extra-large surface area, and have excellent properties in adsorption and energy storage. Unfortunately, the lack of efficient synthesis strategies and the difficulty of doing this on a large-scale have seriously limited their development. We have developed a large-scale simple production route using a relatively low synthesis temperature and direct acetylene chemical vapor deposition (CVD) using Co ion-exchanged zeolite Y (CoY) as the template. The Co2+ confined in the zeolite acts as Lewis acid sites to catalyze the pyrolysis of acetylene through the d-π coordination effect, making carbon deposition occur selectively inside the zeolite at 400 °C rather than on the external surface. By systematically investigating the CVD temperature and time, the optimum conditions of 8 h deposition at 400 °C produces an excellent 3D ordered-microporous structure and outstanding structure parameters (3 000 m2 g−1, 1.33 cm3 g−1). Its CO2 adsorption capacity and selectivity are 2.78 mmol g−1 (25 °C, 100 kPa) and 98, respectively. This simple CVD process allows the synthesis of high-quality ZTCs on a large scale at a low cost.

In‐situ Construction of CNTs Decorated Titanium Carbide on Ti Mesh Towards the Synergetic Improvement of Energy Storage Properties for Aqueous Zinc Ion Capacitors

AbstractThe development of aqueous zinc‐ion capacitors (ZICs) is an effective approach to improve the safety and environmental friendliness of energy storage devices. In this paper, TiC/CNTs core‐shell array structures (TCT) were synthesized on titanium substrate through in‐situ simple chemical vapor deposition and carbon reduction and used as self‐supporting cathodes for aqueous ZICs. As expected, as‐prepared TCT electrode exhibited excellent electrochemical performance in aqueous electrolytes, demonstrating a high specific capacitance of 275.13 F g−1 at a current density of 1.0 A g−1 and maintaining 90.5 % of its initial capacity after 10000 charge‐discharge cycles. The assembled Zn//TCT ZIC displays excellent rate capability, delivering an excellent specific capacitance of 298.2 F g−1 at 0.5 A g−1 and 193.5 F g−1 at a high current density of 10 A g−1. Zn//TCT device can provide an ultra‐high energy density of 24.8 Wh kg−1 at a power of 6984.1 W kg−1. DFT calculations further demonstrate that a large number of electrons are transferred at the TiC/CNT interface and stable TIC−C bonds can be formed. This work provides a new strategy for rationally designing transition metal carbide electrodes and constructing ZICs with high energy and power densities.

Boron, nitrogen, sulphur heteroatom influence effect on direct growth carbon nanotubes on Ni foam for anode electrodes

With the fast expanding market for portable electronic devices and increasing demand for energy storage devices with elevated power and energy density, the biggest challenge facing current researchers is to develop more efficient, low-cost devices. The design and research of carbon nanotubes (CNT) based anode electrode materials has become promising areas of research for supercapacitor technology improvement in energy storage applications. Here, capacitive properties and effects of heteroatoms for example boron (B), sulphur (S), and nitrogen (N) have been investigated for the preparation of direct growth carbon nanotubes by employing simple chemical vapour deposition (CVD) technique. NCNT electrode explored elevated areal capacitance of 6.95 F/cm2 at 0.005 A/cm2, and good capacitive retention of 99.36% at 10 A/g over 10,000 cycles in the three-electrode system. As a result of the favourable bonding of the nitrogen site, the NCNT electrode is a feasible and simple material to enhance the capacitive performance of supercapacitors.

Potential modulation of Nickel-Cobalt hydroxide nanosheets with conductive Poly(3,4-Ethylenedioxythiophene) skin for aqueous hybrid supercapacitors

Transition metal hydroxides with tuned structure and superior electrochemical activities are of potential as positive electrodes for aqueous hybrid supercapacitors (AHSs), yet their conductivities and stacking behaviors need to be optimized to further improve the electrical potential distribution from the electronic multi-contact border to the electroactive center. Herein, we report a new approach to coat poly(3,4-ethylenedioxythiophene) (PEDOT) skin with a controlled thickness on nickel–cobalt layered double hydroxide (NiCo-LDH) nanosheets via a simple yet efficient oxidative chemical vapor deposition (oCVD). The conductive PEDOT skin is ionically permeable, resulting in uniform distribution of the electrical potential and fast transport of ions to active sites. The density functional theory (DFT) calculations reveal that the PEDOT layer can build an embedded electric field at the interface and enable a low desorption energy of hydrogen for electrochemical redox reactions. The as-obtained NiCo-LDH nanosheets with the PEDOT skin of 10 nm thick (LDH/PEDOT-10) as the battery-type electrode deliver a high specific capacity of 167 mAh g−1 (1250F g−1) with a greatly improved rate capability of 79 % at 50 A g−1 and cycling stability of 92 % for 6000 cycles, which endows AHS devices with superior charge-storage performance. This study has demonstrated for the first time that the modulation of electrical potential for redox electrodes via an interface engineering strategy can achieve simultaneously fast reaction kinetics and excellent structure stability for aqueous energy-storage devices.

Large‐Scale, Controllable Synthesis of Ultrathin Platinum Diselenide Ribbons for Efficient Electrocatalytic Hydrogen Evolution

Abstract2D platinum diselenide (PtSe2) exhibits exceptional layer‐dependent electrical properties and high catalytic activity for hydrogen evolution reactions, making it an ideal system for studying structure–activity correlations. However, the synthesis of high‐quality atomically thin PtSe2 materials has proven challenging. This study presents a simple chemical vapor deposition method for synthesizing high‐quality ultrathin 1T‐PtSe2 ribbons on Au foils, making it easily applicable. Theoretical and experimental results confirm that these atomically thin 1T‐PtSe2 ribbons possess abundant catalytic sites and can serve as ideal electrocatalysts. This study advances the large‐scale synthesis and potential application of ultrathin transition metal disulfides and presents a novel method for designing and synthesizing highly active ultrathin catalysts.

Multifunctional nano-cellulose aerogel for efficient oil–water separation: Vital roles of magnetic exfoliated bentonite and polyethyleneimine

Discharge of oily wastewater have caused serious environmental pollution and resources waste. Due to the characteristics of hydrophobic and porous, aerogel has been proved to be a kind of promising oil-adsorbing materials for oil adsorption and recovery. However, dissatisfactory adsorption properties and recovery ability of aerogel for oil pollution treatment were still critical issues hindering aerogel applications. Magnetic exfoliated bentonite (MBTex) possesses good magnetic separation property, anti-mold ability and anti-extruding strength. Meanwhile, Polyethyleneimine (PEI) can cross-link with nano-cellulose to form sponge-like structure and prevent the corrosion of magnetic media. Basing on the above-mentioned characteristics of MB and PEI, a new carboxy cellulose nanofibers/polyethyleneimine/magnetic exfoliated bentonite (CNF-C/PEI/MBTex) aerogel was synthesized using simple hydrothermal and chemical vapor deposition (CVD) methods, and the adsorption and recovery ability of different oil on samples were investigated. The results showed that CNF-C/PEI/MBTex aerogel exhibited superhydrophobic properties (contact angle 151°), excellent mechanical properties (full recovery at 80% pressure), anti-mold properties (the anti-mold efficiency was more than 90%) and magnetic responsivity. Furthermore, CNF-C/PEI/MBTex aerogel exhibited high oil adsorption capacity (24.6 ∼ 77.8 times higher than its original weight) and can recover the adsorbed oil by simple hand squeezing (the adsorption capacity still exceeds 90% after 20 cycles). In summary, the present work provides a valuable reference for the synthesis of high-performance adsorbent materials for oil–water separation using cost-effective clays combined with polymers.

Constructing mixed-dimensional lightweight flexible carbon foam/carbon nanotubes-based heterostructures: An effective strategy to achieve tunable and boosted microwave absorption

Taking full advantage of interface engineering to strengthen interface polarization is an effective strategy to improve microwave absorption. Therefore, constructing the mixed-dimensional heterostructures and/or three-dimensional (3D) interconnected network structures should be attractive pathways to create the abundant interfaces for enhanced interfacial effect. Herein, mixed-dimensional framework structure carbon foam (CF)/carbon nanotubes (CNTs)@Fe3C@Fe3O4 samples consisting of 3D CF, one-dimensional (1D) CNTs and zero-dimensional (0D) Fe3C@Fe3O4 nanoparticles were elaborately designed and produced through a simple catalytic chemical vapor deposition process. The as-prepared CF/CNTs@Fe3C@Fe3O4 heterostructures with the different contents of CNTs could be selectively produced by regulating the pyrolysis time. Owing to the unique structure and excellent synergistic effects, the obtained mixed-dimensional CF/CNTs@Fe3C@Fe3O4 samples presented the excellent comprehensive electromagnetic wave absorption performances (EMWAPs) including strong absorption capabilities, broad absorption bandwidths, thin matching thicknesses and low densities. Furthermore, the obtained results demonstrated that the enhanced content of CNTs greatly boosted their conduction and polarization loss abilities, which resulted in the enhanced comprehensive EMWAPs. Therefore, our findings not only offered a simple strategy to produce the mixed-dimensional framework structure magnetic CF/CNTs-based heterostructures as excellent lightweight high-efficiency microwave absorbers, but also provided an effective pathway to make the best of interface engineering for enhancing interface polarization.