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Abstract Lithium–sulfur (Li–S) batteries have been regarded as promising next‐generation energy‐storage devices owing to their inherently high theoretical energy density. Unfortunately, the poor capacity and cycling life caused by severe polysulfide shuttle effect and sluggish redox kinetics in sulfur cathodes greatly impede the practical application of Li–S batteries. Herein, a new class of nanonetwork‐structured carbon decorated with oxygen‐vacancy‐containing cerium oxide nanoparticles (NSC–CeO2−x), in which carbon skeleton is composed of highly conductive carbon nanotube core welded by hybrid carbon shell, has been developed via one‐step heating treatment of hybrid molecular brush and further employed as functional interlayer to modify separator of Li–S battery. Owing to the synergistic effect of the highly active CeO2−x nanoparticles and the three‐dimensional carbon nanonetwork in enhancing the preservation of the soluble polysulfides and boosting the redox kinetics of sulfur species, the NSC–CeO2−x significantly promotes the electrochemical performance of sulfur cathode. As a result, the as‐constructed Li–S batteries exhibit an ultrahigh initial sulfur utilization of 92.9% and an extremely large capacity of 751 mA h g−1 at a high rate of 5 C. Remarkably, a stable capacity of 728 mA h g−1 over 300 cycles at 1 C is also achieved.

Carbon materials are key components in energy storage and conversion devices and most directly impact device performance. The need for advanced carbon materials has become more pressing with the increasing demand for high-performance energy conversion and storage facilities. Nonetheless, realizing significant performance improvements across devices remains challenging because of the difficulties in controlling irregularly organized microstructures and the specific carbon structures concerned. With the aim of realizing devisable structures, adjustable functions, and performance breakthroughs, this review proposes the concept of superstructured carbons. In fact, superstructured carbons are a category of carbon-based materials characterized by precisely built pores, networks, and interfaces. This unique category meets the particular functional demands of high-performance devices and exceeds the rigid structure of traditional carbons. In the context of these superstructured carbons, we present methods for realizing both custom-built structures and target-oriented functionalities. For specific energy-related reactions, we emphasize the targeted property-structure relationships in these well-defined superstructured carbons. Finally, future developments and practicability challenges of superstructured carbons are also proposed.

Abstract Carbon‐based nanomaterials have been regarded as promising non‐noble metal catalysts for renewable energy conversion system (e.g., fuel cells and metal–air batteries). In general, graphitic skeleton and porous structure are both critical for the performances of carbon‐based catalysts. However, the pursuit of high surface area while maintaining high graphitization degree remains an arduous challenge because of the trade‐off relationship between these two key characteristics. Herein, a simple yet efficient approach is demonstrated to fabricate a class of 2D N‐doped graphitized porous carbon nanosheets (GPCNSs) featuring both high crystallinity and high specific surface area by utilizing amine aromatic organoalkoxysilane as an all‐in‐one precursor and FeCl3·6H2O as an active salt template. The highly porous structure of the as‐obtained GPCNSs is mainly attributed to the alkoxysilane‐derived SiOx nanodomains that function as micro/mesopore templates; meanwhile, the highly crystalline graphitic skeleton is synergistically contributed by the aromatic nucleus of the precursor and FeCl3·6H2O. The unusual integration of graphitic skeleton with porous structure endows GPCNSs with superior catalytic activity and long‐term stability when used as electrocatalysts for oxygen reduction reaction and Zn–air batteries. These findings will shed new light on the facile fabrication of highly porous carbon materials with desired graphitic structure for numerous applications.

The authors use polyacrylamide grafted graphene oxide as a molecular brush to coat the commercial polypropylene separator. The bilayer design combines lithiophilicity chemistry and high mechanical strength, rendering high performance Li metal anodes and offering a strategy for the design of separators.

Abstract An activated carbon aerogel (ACA-500) with high surface area (1765 m2 g−1), pore volume (2.04 cm3 g−1), and hierarchical porous nanonetwork structure is prepared through direct activation of organic aerogel (RC-500) with a low potassium hydroxide ratio (1:1). Based on this substrate, a polyaniline (PANi)-coated activated carbon aerogel/sulfur (ACA-500-S@PANi) composite is prepared via a simple two-step procedure, including melt-infiltration of sublimed sulfur into ACA-500, followed by an in situ polymerization of aniline on the surface of ACA-500-S composite. The obtained ACA-500-S@PANi composite delivers a high reversible capacity up to 1208 mAh g−1 at 0.2C and maintains 542 mAh g−1 even at a high rate (3C). Furthermore, this composite exhibits a discharge capacity of 926 mAh g−1 at the initial cycle and 615 mAh g−1 after 700 cycles at 1C rate, revealing an extremely low capacity decay rate (0.48‰ per cycle). The excellent electrochemical performance of ACA-500-S@PANi can be attributed to the synergistic effect of hierarchical porous nanonetwork structure and PANi coating. Activated carbon aerogels with high surface area and unique three-dimensional (3D) interconnected hierarchical porous structure offer an efficient conductive network for sulfur, and a highly conductive PANi-coating layer further enhances conductivity of the electrode and prevents the dissolution of polysulfide species.

ABSTRACT A facile method is developed to synthesize silicone-toughened unsaturated polyester (SUP-M) by monomer copolymerization of anhydrides and diols with hydroxyl-terminated silicone. The structures and molecular weights of the SUP-M resins were characterized by Fourier transform infrared spectroscopy and gel permeation chromatography, respectively. The gelation time and mechanical properties, including impact strength, flexural strength, and tensile strength, were investigated. The fracture behaviors were studied by scanning electron microscopy, and their glass-transition temperature and storage modulus were measured by dynamic mechanical analysis. The experimental results showed that the impact strength of SUP-M can be obviously improved through copolymerization with a small amount of silicone without decreasing its mechanical properties. The impact strength, flexural strength, and tensile strength of SUP-M-0.5 are as high as 12.5 KJ m−2, 131 MPa, and 59 MPa, which are increased by 76.1%, 21.2%, and 6.7%, respectively, compared with those of unsaturated polyester. Impacts on SUP-M with low silicone content produce a large number of evenly and regularly distributed continuous narrow crack bands combined with many evenly distributed branching crazes, which are of great benefit in absorbing a large amount of impact energy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45562. [ABSTRACT FROM AUTHOR]

A nanopores array in ordered mesoporous materials matters significantly to the reactant molecules arriving at the active catalytic sites in the interior of the nanostructure. However, how this effect works in the case of electrocatalysis needs investigating. We present that the nanopores array of carbon supports plays a significant role in determining Pt's accessibility and electroactivity. The ordered mesoporous carbons with interconnected pore channels (CMK-3) provide Pt nanoparticles with more than one order of magnitude superior Pt utilization efficiency and alcohol electrooxidation activity to those with isolated pore channels by carbon wall (FDU-15). This becomes more prominent in the case of the electrooxidation of isopropanol with a bigger molecular size and lower polarization. These findings indicate the significant role of nanoarchitectures in Pt's accessibility and electroactivity. It is possible to extend this concept to the other fine chemistry typical of surface activity and facile mass transport of molecules. [ABSTRACT FROM AUTHOR]

Hierarchical porous carbon with ultrahigh surface area (i.e., 3350 m2g−1) is prepared by utilizing the natural well-defined organization of pores present in sisal fibers as the substrate for constructing hierarchical macro–meso–microporous structure, which allows for rapid molecular diffusion and high pore utilization and thus leads to excellent organic vapour adsorption performance. [ABSTRACT FROM AUTHOR]

In this paper, we report the electrochemical capacitive properties of polystyrene-based hierarchical porous carbon (PS-HPC) for supercapacitors. Compared to many porous carbons such as a commercially available activated carbon and an ordered mesoporous carbon, PS-HPC has a unique three-dimensionally (3D) interconnected micro-, meso- and macroporous network and thus exhibits faster ion transport behavior and a larger utilization of surface area in electric double layer capacitors. The 3D interconnected meso- and macroporous network originates respectively from the compact and loose aggregation of crosslinked polystyrene-based carbon nanoparticles, and is able to facilitate rapid ion transfer/diffusion rates. Furthermore, PS-HPC's micropores exist from the 3D interconnected network inside these crosslinked polystyrene-based carbon nanoparticles, thus giving an exceptional electrochemically accessible surface area for charge accumulation. As a result, the capacitance retention ratio and capacitance per surface area of PS-HPC at a high sweep rate of 200 mV s−1are as high as 84% and 28.7 μF cm−2, respectively. These encouraging results demonstrate the promising application of PS-HPC for high performance supercapacitors. [ABSTRACT FROM AUTHOR]

A new type of nanoporous carbon material by pyrolysis of styrene-acrylonitrile random copolymer (SAN)/multiwalled carbon nanotube (MWCNT) composite was prepared. The thermal decomposable styrene component of the SAN could act as a soft template to form abundant nanopores with the help of the pristine nanotubular framework of the MWCNT. The measured Brunauer-Emmett-Teller surface area of the SAN/ MWCNT-based carbon was up to 376 m²/g with a MWCNT content of 10 wt%, 11 and 14 times as large as those of SAN-based and polyacrylonitrile/MWCNT-based carbons, respectively. As a result, the highest specific capacitance of an as-prepared SAN/MWCNT-based carbon reached 118 F/g, which is much higher than those of the latter two. [ABSTRACT FROM AUTHOR]

A simple and effective template-free method to fabricate hierarchical porous carbon (HPC) has been successfully developed by adopting linear polystyrene resin as raw material, anhydrous aluminium chloride as Friedel–Crafts catalyst, and carbon tetrachloride as crosslinker and solvent. Experimental results show that the as-constructed carbonyl (–CO–) crosslinking bridges between polystyrene chains provide simultaneously to its hierarchical porous polystyrene precursor, both a high crosslinking density and a proper amount of oxygen atoms, and thus achieve good framework carbonizability and nanostructure inheritability during carbonization. The as-prepared HPC's hierarchical porous structure exhibits interesting uniqueness: micropores (<2 nm) are from the network inside crosslinking polystyrene-based carbon nanoparticles of 10–30 nm in size, and mesopores (2–50 nm) and macropores (50–400 nm) result from the compact and loose aggregation of these network nanoparticles, respectively; and these micro-, meso- and macropores are three-dimensionally interconnected to each other. Its Brunauer–Emmett–Teller surface area and total pore volume are 679 m2g−1and 0.66 cm3g−1, respectively. [ABSTRACT FROM AUTHOR]

Abstract  In this paper, we investigated the requirements of organic gels for a successful ambient pressure drying by analyzing the role of the strength, the pore size and the surfactant of organic gels in decreasing the drying shrinkage of organic aerogels. Experimental results showed the effect of the decrease of the surface tension, resulting from the surfactant, on the drying shrinkage was very small and negligible. The drying shrinkage depended strongly on the strength and the pore size. Subsequently, the respective role of the strength and the pore size was evaluated. It can be found that the strength plays a greater role than the pore size. [ABSTRACT FROM AUTHOR]

In this article, activated carbon aerogels (ACAs) were prepared by CO2 activation. Their pore structures were investigated by N2 adsorption–desorption analysis. ACAs have excellent microporosity (e.g. 0.36 cm3/g) and mesoporosity (e.g. 1.72 cm3/g). Adsorption characteristics of phenol, methylene blue, I2, and VB12 on ACAs in the liquid phase were studied by static adsorption experiments. Results showed that CO2 activation process is an effective way to introduce micropores in carbon aerogels, which is enhanced with the increase of activation time. As a result, the adsorption capacities of the four mentioned adsorbates on ACAs were improved gradually with the increase of activation time. However, mesopore volume is also a factor on improving adsorption properties for the relatively giant molecules methylene blue and VB12. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [ABSTRACT FROM AUTHOR]

Abstract Phenol can be used as a cheap raw material to prepare organic and carbon aerogels based upon the gelation and supercritical drying in ethanol. In addition, organic and carbon aerogels could also be obtained by directly drying phenol-furfural alco-gels at ambient pressure under proper preparation conditions. The effect of the preparation conditions, such as the phenol-furfural (PF) concentration, the mass ratio of HCl to phenol (HCl/P), the mole ratio of phenol to furfural (P/F) and the gelation temperature, on the gelation ability and the bulk density was studied. The aerogels obtained have a three-dimensional network that consists of approximately 20 nm particles, which define numerous mesopores with diameter less than 50 nm. Organic aerogels obtained have high BET surface areas of 267–503 m/g and large mesopore volumes of 0.657–2.734 cm/g. Carbonization generates numerous micropores of ca. 0.45 nm in diameters but impairs to some extent the mesopore structure. As a result, carbon aerogels have high BET surface areas of 507–561 m/g, large micropore volumes of 0.106–0.168 cm/g and small mesopore volumes of 0.505–0.710 cm/g relative to their organic aerogel precursors. XRD characterization indicates that carbon aerogels are more crystalline than activated carbon but less than graphite. [ABSTRACT FROM AUTHOR]

Activated carbon fiber/carbon aerogel (ACF/CA) composites were fabricated by gelling a mixture of ACF and resorcinol and furfural, followed by supercritical drying of the mixture in isopropanol. The product then went through carbonization in a nitrogen atmosphere. The fabrication conditions, such as the mass content of R-F, the content of the ACF added, and the gelation temperature, were explored. The textures and pore structures of the ACF/CA composites thus obtained were characterized using transmission electron microscopy, scanning electron microscopy, and a surface area analyzer. The mechanical properties of the samples were assessed primarily through compressive tests. The experimental results indicated that the added ACF disperses uniformly in the resulting ACF/CA composites. The carbon matrix of the ACF/CA composites also consisted of interconnected carbon nanoparticles with sizes in the range of 20 to 30 nm. The ACFs can reinforce the related carbon aerogels when they originally have low mass density and are weak in mechanical strength. When large amounts of ACF were added to the composites, the micropore area and micropore volume of the composites increased, but their external surface area decreased. The mesopore volumes and the related diameters and mesopore size distributions of the ACF/CA composites were mainly affected by the mass density of the composites. The micropore sizes of all the composites were sharply concentrated at about 0.5 nm. [ABSTRACT FROM AUTHOR]

Cu-loaded carbon aerogel was prepared by soaking sol-gel production, obtained from K-salt of 2,4-dihydroxybenzoic acid, into Cu(NO 3 ) 2 solution. XPS measurement demonstrated that Cu concentration is higher in the outside region of bulk samples, indicating that Cu may be incorporated through an immersing process rather than ion-exchanging. TEM observation showed that, like an aerogel sample with K ions, Cu-loaded organic aerogels had porous texture in which gel particles about 20-30 nmφ were interconnected with each other. Metal-loading process used in this study was considered as a promising method to disperse metals without changing original structure of carbon aerogels. [ABSTRACT FROM AUTHOR]

Conjugated microporous polymers are developed as a new platform for lithium-battery energy storage, which features a near-unity coulombic efficiency, high capacity and cycle stability. The polymers exhibit synergistic structural effects on facilitating charge dynamics by virtue of their built-in redox skeletons, open nanopores and large surface areas. [ABSTRACT FROM AUTHOR]

Studies the effect of addition of inhibitor carbon monoxide in activating gas on the pore structure of activated carbon fiber with carbon dioxide activation. Characteristics of activated carbon fibers; Nitrogen adsorption isotherms; Relation between the decrease in the total pore volume and mesopore volume and the increase in carbon monoxide flow rate.