Meikang Han

Meikang Han
Fudan University · Institute of Optoelectronics

PhD

About

41
Publications
14,007
Reads
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5,054
Citations
Additional affiliations
May 2018 - present
Drexel University
Position
  • PostDoc Position

Publications

Publications (41)
Article
MXenes are an emergent class of two-dimensional materials with a very wide spectrum of promising applications. The synthesis of multiple MXenes, specifically solid-solution MXenes, allows fine tuning of their properties, expands their range of applications, and leads to enhanced performance. The functionality of solid-solution MXenes is closely rel...
Article
Achieving pseudocapacitive intercalation in MXenes with neutral aqueous electrolytes and driving reversible redox reactions is scientifically appealing and practically useful. Here, we report that the partial oxidation of MXene intensifies pseudocapacitive Li+ intercalation into Ti3C2Tx MXene from neutral water-in-salt electrolytes. An in situ X-ra...
Article
MXenes are promising pseudocapacitive materials with ultrahigh specific capacitance. Currently, more than 30 stoichiometric MXene compositions and about 20 solid solutions have been experimentally synthesized. However, most studies focus on Ti3C2Tx or a few other single-M MXenes, and little is known about the electrochemical properties of solid-sol...
Article
MXenes occupy a leading position among materials capable of providing lightweight shielding against electromagnetic interference (EMI) owing to their outstanding metallic conductivity, low density, tunable surface chemistry, and easy solution processing. In this work, we demonstrate that multiple interfaces of segregated structures in MXene composi...
Preprint
Full-text available
Low and selective infrared emission materials are necessary for next generation thermal technologies, including passive heating, infrared identification, and photothermal conversion. Here, we report on the intrinsic infrared radiation properties of three MXenes: Ti3C2Tx, Ti3CNTx, and V4C3Tx. The infrared emissivity of 200 nm thick Ti3C2Tx coating i...
Article
High throughput manufacturing of regenerable nanomaterial-based flexible electronics represents an extreme challenge. Here we demonstrate a rapid and eco-friendly assembly and regeneration of nanomaterial networks (films) on a hydrophobic polymer substrate (i.e., polydimethylsiloxane) from a sonicated dispersion of hydrophobic nanoparticles in wate...
Article
Full-text available
Highly integrated, flexible, and ultrathin wireless communication components are in significant demand due to the explosive growth of portable and wearable electronic devices in the fifth‐generation (5G) network era, but only conventional metals meet the requirements for emerging radio‐frequency (RF) devices so far. Here, it is reported on Ti3C2Tx...
Article
As an increasing number of wireless devices are introduced to our daily lives, long-term environmentally stable conductive fabrics that can shield against electromagnetic radiation are increasingly desired. Herein, conventional cotton and linen fabrics were dip-coated in additive-free, aqueous Ti3C2Tx MXene dyes, which consist of only two-dimension...
Article
Full-text available
Alloying is a long-established strategy to tailor properties of metals for specific applications, thus retaining or enhancing the principal elemental characteristics while offering additional functionality from the added elements. We propose a similar approach to the control of properties of two-dimensional transition metal carbides known as MXenes...
Article
Full-text available
Free‐standing films that display high strength and high electrical conductivity are critical for flexible electronics, such as electromagnetic interference (EMI) shielding coatings and current collectors for batteries and supercapacitors. 2D Ti3C2Tx flakes are ideal candidates for making conductive films due to their high strength and metallic cond...
Article
Full-text available
In article number 2001093, Joselito M. Razal and co‐workers demonstrate that ordered domains of additive‐free Ti3C2Tx MXene liquid crystals can be processed into micrometer‐thin films that do not compromise mechanical properties for electrical conductivity, enabling the development of high‐performance devices and new applications.
Article
Two-dimensional transition metal carbides, nitrides and carbonitrides, popular by the name MXenes, are a promising class of materials as they exhibit intriguing optical, optoelectronic and electrochemical properties. Taking advantage of their metallic conductivity and hydrophilicity, titanium carbide MXenes enable solution processable transparent c...
Article
Two-dimensional transition metal carbides and nitrides (MXenes) have accumulated tremendous interest recently due to their high conductivity and excellent figures of merit in electromagnetic interference shielding and other applications. Large-area freestanding films of MXenes are important for versatility in application; however, alternative proce...
Article
Thin films of two-dimensional MXene (Ti3C2Tx) are evaluated in terms of their conductivity over the radio frequency (RF) range of 1–10 GHz using a custom designed test fixture. A contactless method is developed for extracting the conductivity of MXene films of various thickness (1.0–4.3 μm) at RF frequencies. Open ended MXene transmission lines wit...
Article
New ultrathin and multifunctional electromagnetic interference (EMI) shielding materials are required for protecting electronics against electromagnetic pollution in the fifth-generation networks and Internet of Things era. Micrometer-thin Ti3C2T x MXene films have shown the best EMI shielding performance among synthetic materials so far. Yet, the...
Article
Lightweight materials with high electrical conductivity and robust mechanical properties are highly desirable for electromagnetic interference (EMI) shielding in modern portable and highly integrated electronics. Herein, a three-dimensional (3D) porous Ti3C2T x /carbon nanotube (CNT) hybrid aerogel was fabricated via a bidirectional freezing method...
Article
Full-text available
Ti3C2Tx MXene is an attractive two-dimensional (2D) material for a wide variety of applications, however measured properties vary widely from study to study. A potential factor to the property differences relates to variability in the MAX phase precursors. To illustrate this, Ti3AlC2, the precursor for Ti3C2Tx MXene, was synthesized using three car...
Article
Lightweight and mechanically flexible materials that can provide efficient electromagnetic interference (EMI) shielding are highly desirable for protecting portable and smart electronic devices against electromagnetic pollution. Here, the authors report a tunable design of a three‐dimensional (3D) porous aerogel structure made of 2D transition meta...
Article
Full-text available
A broadband microwave absorbing composite with a multi-scale layered structure is proposed, in which a reduced graphene oxide (RGO) film sandwiched between two layers of epoxy glass fiber laminates serves as the frequency selective surface (FSS). RGO films with the desired electrical properties were synthesized directly by hydrothermal reaction, va...
Article
2D few-layered Ti3C2TX MXene (f-Ti3C2TX) has been proved to be one of the most promising electromagnetic interference (EMI) materials, but its EM absorption properties and loss mechanism have not been studied so far. Herein, for the first time, ordered lamellar f-Ti3C2TX/SiCnws hybrid foams with ultralow density are synthesized by a combination of...
Article
Water-based polyurethane/alumina hollow microsphere (WPU-hAl2O3) composite films were prepared via a facile spin coating method. The pristine WPU, as the matrix of the composite films, was tailor-made by hAl2O3 with the diameter of 2-5 μm to improve the mechanical and physical properties of the films. The hardness, surface morphology, infrared emis...
Article
Electromagnetic (EM) absorbing and shielding materials have attracted great interests due to the increasing electromagnetic pollutions in the past years. Microstructure plays a crucial role in determining the performance of the above materials. Herein, a scale‐like structure based on Ti3C2 Mxenes is proposed to approach improved EM absorption prope...
Article
Red blood cell like-mesoporous carbon hollow microspheres (RBC-PCHMs) have been synthesized by modified stöber method with following pyrolysis and etching procedures. The as-synthesized carbon spheres show unique red blood cell like morphology with interior void and mesoporous shell. The composite mixing phenolic resin with 10 wt. % RBC-PCHMs exhib...
Article
Full-text available
Ti2CTx MXene and derivatives with various heterogeneous structure are constructed via etching and a facile oxidation treatment. Effect of the different oxidation conditions on the structure evolution and phase composition is studied in detail. Compared with the pristine Ti2CTx MXene, the improvement in the electromagnetic wave absorption capability...
Article
Full-text available
Microwave absorbers with layered structures that can provide abundant interfaces are highly desirable for enhancing electromagnetic absorbing capability and decreasing the thickness. The atomically thin layers of two-dimensional (2D) transition metal carbides (MXenes) make them a convenient precursor for synthesis of other 2D and layered structures...
Article
Full-text available
Ti3C2Tx MXenes modified with in situ grown carbon nanotubes (CNTs) are fabricated via a simple catalytic chemical vapor deposition (CVD) process. The as-prepared Ti3C2Tx/CNT nanocomposites show that one-dimensional (1D) carbon nanotubes are uniformly distributed in the interlayers of two-dimensional (2D) Ti3C2Tx MXene flakes. Compared with the pris...
Article
Three-dimensional (3D) flexible foams consisting of reduced graphene oxides (rGO) and in-situ grown SiC nanowires (NWs) were prepared using freeze-drying and carbothermal reduction process. By means of incorporating SiC nanowires into rGO foams, both the thermostability and electromagnetic absorption of the composites were improved. It was demonstr...
Article
Three-dimensional (3D) macroscopic covalently bonded carbon nanowires/graphene (CNWs/G) architectures can achieve the extraordinary properties based on theoretical work. A series of 3D structures have been recently fabricated. However, these architectures are far from theoretical model because CNWs are difficult to perfectly connect with the graphe...
Article
In this work, mesoporous carbon hollow microspheres (PCHMs) with designable mesoporous shell and interior void are constructed by a facile in situ stöber templating approach and a pyrolysis-etching process. The PCHMs are characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectra, Raman, nitrogen ads...
Article
The porous alumina ceramics with closed pores were fabricated using C@Al2O3 microspheres as pore-forming agent. The closed pores with a diameter about 5 μm were successfully obtained in the dense matrix, owing to the additive C@Al2O3 microspheres. Different amount of C@Al2O3 microspheres was added to investigate the effects of closed pores on therm...
Article
Full-text available
Electromagnetic (EM) absorbing and shielding composites with tunable absorbing behaviors based on Ti3C2 MXenes are fabricated via HF etching and annealing treatment. Localized sandwich structure without sacrificing the original layered morphology is realized, which is responsible for the enhancement of EM absorbing capability in the X-band. The com...
Article
Strontium-doped barium aluminosilicate ceramics were prepared by the sol-gel and hot-pressing processes. The experimental results show that doped Sr promotes the hexacelsian-to-celsian phase transformation of barium aluminosilicate ceramics. When the mass ratio of Sr increases, the dielectric constant of the samples decreases from 6.03 to 5.37, whi...
Article
A high-performance electromagnetic wave absorbing composite based on graphene and polysiloxane-derived SiOC ceramic is realized via the polymer pyrolysis process. Hierarchical architecture consisting of two-dimensional graphene and one-dimensional SiC nanowire in ceramic matrix is achieved owing to the heterogeneous nucleation of SiC nanowires prom...
Article
BaAl2Si2O8 (BAS) glass-ceramic powders were prepared by sol-gel method. Graphene oxide (GO)/BAS mixture powders were prepared by a simple mixing process of GO and BAS. Dense and uniform reduced graphene oxide (RGO)/BAS composites were fabricated by the hot-pressing of GO/BAS, which was accompanied by the in-situ thermal reduction of GO. Microstruct...
Article
Core/shell structured C/ZnO nanoparticles were synthesized by a two-step process based on hydrothermal method. The experimental results show that ZnO nanoparticles attach on the surface of carbon spheres through the surfacial functional groups. The core/shell structure enhances the electromagnetic wave attenuation capability owing to defects, multi...
Article
Nano SiC modified silicon oxycarbide (n-SiC/SiOC) ceramics were prepared through the pyrolysis of a mixture of liquid polysiloxane and n-SiC with an average grain diameter of 30 nm. After adding n-SiC, palingenetic SiC nanograins with an average grain diameter smaller than 10 nm, and nanosized free carbon were gradually separated from the amorphous...
Article
Carbon nanotube-ZnO composite powders, which act as high-temperature electromagnetic wave absorbents, are prepared by homogeneous precipitation. Carbon nanotube-ZnO/glass composites are fabricated by pressureless sintering. ZnO nanoparticles are assembled on the surface of carbon nanotubes, which produces heterostructure and enhances polarization a...
Article
Graphene-wrapped ZnO hollow spheres were synthesized by a two-step process which combined hydrothermal reaction with surface modification. The experimental results show that reduced graphene oxide sheets entirely adhere to the surface of ZnO hollow sphere consisting of nanoparticles. The unique structure effectively decreases the density of the com...
Article
ZAO ceramic target was fabricated by cold isotatic pressing and pressureless sintering ZAO powder used method of homogeneous precipitation. Then, ZAO film was deposited by RF magnetron sputtering of the lab-made ZAO target. The microstructures and phases of ZAO target and its film were characterized by scanning electron microscopy (SEM), energy dis...

Projects

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Project