Integration of graphene with polymers to construct three-dimensional porous graphene/polymer composites (3DGPCs) has attracted considerable attention in the past few years for both fundamental ...studies and diverse technological applications. With the broad diversity in molecular structures of graphene and polymers via rich chemical routes, a number of 3DGPCs have been developed with unique structural, electrical, and mechanical properties, chemical tenability, and attractive functions, which greatly expands the research horizon of graphene-based composites. In particular, the properties and functions of the 3DGPCs can be readily tuned by precisely controlling the hierarchical porosity in the 3D graphene architecture as well as the intricate synergistic interactions between graphene and polymers. In this paper, we review the recent progress in 3DGPCs, including their synthetic strategies and potential applications in environmental protection, energy storage, sensors, and conducting composites. Lastly, we will conclude with a brief perspective on the challenges and future opportunities.
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IJS, KILJ, NUK, PNG, UL, UM
The increasing concerns about environmental issues caused by fossil fuels, and the demand for renewable energy have trigged extensive research into efficient energy storage and conversion systems. ...Owning to their unique properties of a high specific area, well-defined pore size, and tunable molecular structure, 2D metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs), as two typical classes of 2D porous polymers, have been considered as intriguing materials for energy storage and conversion. This review provides a comprehensive overview of the up-to-date synthesis strategies of 2D MOFs and COFs, and their further applications. We mainly focus on the top-down and bottom-up synthesis methods, and applications in supercapacitors, lithium-ion batteries, batteries beyond lithium-ion batteries (lithium-sulfur batteries, and sodium-ion batteries), and electrocatalysts for CO
2
reduction, oxygen evolution, oxygen reduction, and hydrogen evolution.
The synthetic methods of two-dimensional polymers and their applications in energy storage and conversion are reviewed with an emphasis on the underlying method-structure-property relationships.
Functionalized graphene hydrogels are prepared by a one‐step low‐temperature reduction process and exhibit ultrahigh specific capacitances and excellent cycling stability in the aqueous electrolyte. ...Flexible solid‐state supercapacitors based on functionalized graphene hydrogels are demonstrated with superior capacitive performances and extraordinary mechanical flexibility.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The synthesis of crystalline two-dimensional polymers (2DPs) with proper bandgaps and well-defined repeating units presents a great challenge to synthetic chemists. Here we report the first solution ...synthesis of a single-layer/few-layer triazine-based 2DP via trimerization of carbonitrile at the interface of dichloromethane and trifluoromethanesulfonic acid. The processable triazine-based 2DP can be assembled into mechanically strong layered free-standing films with a high specific surface area via filtration. Moreover, the highly crystalline triazine-based 2DP can function as the active semiconducting layer in a field-effect transistor via drop coating and exhibits slightly bipolar behavior with a high on/off ratio of 103 and a remarkable mobility of 0.15 cm2 V–1 s–1.
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IJS, KILJ, NUK, PNG, UL, UM
2D transition metal carbides and/or nitrides (MXenes), by virtue of high electrical conductivity, abundant surface functional groups and excellent dispersion in various solvents, are attracting ...increasing attention and showing competitive performance in energy storage and conversion applications. However, like other 2D materials, MXene nanosheets incline to stack together via van der Waals interactions, which lead to limited number of active sites, sluggish ionic kinetics, and finally ordinary performance of MXene materials/devices. Constructing 2D MXene nanosheets into 3D architectures has been proven to be an effective strategy to reduce restacking, thus providing larger specific surface area, higher porosity, and shorter ion and mass transport distance over normal 1D and 2D structures. In this review, the commonly used strategies for manufacturing 3D MXene architectures (3D MXenes and 3D MXene‐based composites) are summarized, such as template, assembly, 3D printing, and other methods. Special attention is also given to the structure–property relationships of 3D MXene architectures and their applications in electrochemical energy storage and conversion, including supercapacitors, rechargeable batteries, and electrocatalysis. Finally, the authors propose a brief perspective on future opportunities and challenges for 3D MXene architectures/devices.
3D MXene architectures, by virtue of their high surface area, outstanding electrical conductivity, rich ion transport channels, abundant functional groups, and high reactivity, show great potential for electrochemical energy storage and conversion. This review summarizes the commonly used strategies for the construction of 3D MXene architectures, and their applications in supercapacitors, rechargeable batteries, and electrocatalysis.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Lithium-sulfur batteries can deliver significantly higher specific capacity than standard lithium ion batteries, and represent the next generation of energy storage devices for both electric vehicles ...and mobile devices. However, the lithium-sulfur technology today is plagued with numerous challenges, including poor sulfur conductivity, large volumetric expansion, severe polysulfide shuttling and low sulfur utilization, which prevent its wide-spread adoption in the energy storage industry. Here we report a freestanding three-dimensional （3D） graphene frame- work for highly efficient loading of sulfur particles and creating a high capacity sulfur cathode. Using a one-pot synthesis method, we show a mechanically robust graphene-sulfur composite can be prepared with the highest sulfur weight content （90% sulfur） reported to date, and can be directly used as the sulfur cathode without additional binders or conductive additives. The graphene-sulfur composite features a highly interconnected graphene network ensuring excellent conductivity and a 3D porous structure allowing efficient ion transport and accommodating large volume expansion. Additionally, the 3D graphene framework can also function as an effective encapsulation layer to retard the polysulfide shuttling effect, thus enabling a highly robust sulfur cathode. Electrochemical studies show that such composite can deliver a highest capacity of 969 mAh-g-1, a record high number achieved for all sulfur cathodes reported to date when normalized by the total mass of the entire electrode. Our studies demonstrate that the 3D graphene framework represents an attractive scaffold material for a high performance lithium sulfur battery cathode, and could enable exciting opportunities for ultra-high capacity energy storage applications.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Graphene sheets were stably dispersed in water by functionalization with sulfonated polyaniline (SPANI), and the composite film of SPANI-functionalized graphene showed improved electrochemical ...stability and enhanced electrocatalytic activity.
3D electrodes with interconnected and interpenetrating pathways enable efficient electron and ion transport. In this Review, the design and synthesis of such 3D electrodes are discussed, along with ...their ability to address charge transport limitations at high areal mass loading and to enable composite electrodes with an unprecedented combination of energy and power densities in electrochemical energy storage devices.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Conducting polymers generally show high specific capacitance but suffer from poor rate capability and rapid capacitance decary which greatly limits their practical applications in supercapacitor ...electrodes. To this end, many studies have focused on improving the overall capacitive performance by synthesizing nanostructured conducting polymers or by depositing a range of coatings to increase the active surface area exposed to the electrolyte and enhance the charge transport efficiency and structural stability. Despite this, simultaneously achieving high specific capacitance, good rate performance, and long cycle life remains a considerable challenge. Among the various two-dimensional （2D） layered materials, octahedral （1T） phase molybdenum disulfide （MoS2） nano- sheets have high electrical conductivity, large specific surface areas, and unique surface chemical characteristics, making them an interesting substrate for the controlled growth of nanostructured conducting polymers. This paper reports the rational synthesis of carbon shell-coated polyaniline （PANI） grown on 1T MoS2 monolayers （MoS2/PANI@C）. The composite electrode comprised of MoS2/ PANI@C with a -3 nm carbon shell exhibited a remarkable specific capacitance of up to 678 F-g-1 （1 mV.s-1）, superior capacity retention of 80% after 10,000 cycles and good rate performance （81% at 10 mV.s-1） due to the multiple synergic effects between the PANI nanostructure and 1T MoS2 substrates as well as protection by the uniform thin carbon shell. These properties are comparable to the best overall capacitive performance achieved for conducting polymers-based supercapacitor electrodes reported thus far.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We report the preparation of mechanically strong and ductile poly(vinyl alcohol)/graphene oxide (GO) composite films with a layered structure simply by vacuum filtration. The Young’s modulus and ...tensile yield strength of the composite film containing 3
wt.% GO were measured to be 4.8
GPa and 110
±
7
MPa, respectively. Furthermore, it is flexible and exhibits a large elongation at break (36
±
4%). The high mechanical properties of the composite films are mainly due to the homogeneous dispersion and alignment of GO sheets in the polymer matrix and strong interfacial interactions between both components.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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