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Activated carbon fiber is an effective reducing agent for many high oxidation state ions. The reduction-adsorption capacity for Pt(IV) of activated carbon fibers derived from viscose rayon, sisal, and pitch were studied by chemical analysis of the reaction solutions and XPS study of the deposited platinum. The reduction-adsorption capacity of the viscose-based fibers was found to be the highest. The reduction-adsorption capacity of the fibers increased with the time of activation. Significant reduction capacity was found on the viscose-based fiber even without activation. Under the acidic reaction condition, the deposited platinum was mainly in the elemental state. In the alkaline condition, the hydrolysis of Pt(IV) ions leads to the formation of PtO, which was not further reduced at room temperature. Heating of the specimen to 400 °C or above in vacuum converted the platinum to the elemental state.

In this paper, the reduction role of activated carbon fibre (ACF) for gold ions (Au 3+ ) was studied. On this basis, a technique for concentrating and recovering gold from solution was developed. The experimental results indicated that gold ions (Au 3+ ) can be adsorbed and reduced to elemental gold by ACF and the reduction-adsorption capacity of ACF for Au 3+ can reach 3000 mg Au/g ACF. The elemental gold produced crystallized on the surface of the ACF during the reaction. By the use of ACF paper to recovery Au 3+ from solution, a high recovery rate and capacity can be obtained. The use of ACF to smelt gold from solutions of gold ore can also produce high selectivities for gold.

In the present paper, we demonstrate the importance of the role of a mass transport pathway (MTP) in wormholelike mesoporous carbon (WMC) through studying the ion diffusion behaviors within two different wormholelike mesopore networks with and without MTP. Our results reveal that the introduction of MTP is very helpful in improving ion diffusion properties. The as-prepared WMC with a MTP of ca. 9.7 nm exhibits notably better electric double layer performance as compared to the conventional WMC without a MTP. For example, even at the quick sweep rate of 50 mV s(-1), the surface specific capacitance of the former is 21.6 microF cm(-2), which is almost 4 times as high as that of the latter (5.5 microF cm(-2)).

A novel type of hierarchical porous carbon has been successfully prepared by constructing intra- and inter-sphere -CO- crosslinking bridges of monodisperse styrene-divinylbenzene copolymer nanospheres. The -C(6)H(4)- crosslinking bridges ensure good stability of the nanospheres during swelling and crosslinking, and the -CO- crosslinking bridges play an important role in achieving good nanostructure inheritability during carbonization.

Polyaniline (PANI) with carbon aerogel (CA) as conducting filler has been synthesized by an in situ chemical oxidative polymerization method. Scanning electron microscopy, infrared spectra, cyclic voltammetry and X-ray diffraction indicate that the three-dimensional carbon nano-network of CA is entirely buried inside the PANI matrix and its introduction basically does not change the structure of PANI. The electrochemical performances of the as-prepared PANI materials with CA filler are evaluated by means of galvanostatic charge-discharge test, cyclic voltammetry and electrochemical impedance spectroscopy. It is found that the electrochemical performances of PANI are notably improved due to the introduction of CA filler. For example, when operating at a large current density of 50 mA cm(-2), CA-modified PANI with the optimal CA/aniline ratio of 1.0 wt% exhibits a specific capacitance as high as 226 F g(-1), whereas neat PANI has only 89 F g(-1). The CA modification mechanism of PANI has been discussed in detail.

In this work, kinetics of phase separation in the blends of polystyrene (PS) and poly(vinyl methyl ether) (PVME) was investigated by a simple and sensitive method, i.e., resonance light scattering (RLS) spectroscopy. Owing to the aggregation of chromophores (phenyl rings) in the systems when phase separation occurred, RLS intensities were drastically enhanced and hence acted as a characteristic indicator. At the early stage of phase separation, two different RLS behaviors corresponding to spinodal decomposition (SD) and nucleation and growth (NG) were observed. The Cahn-Hilliard (C-H) linearization theory was found not applicable for kinetics analysis of the scattering data at lambda346 nm due to RLS effect near the absorption band. Based on a decomposition reaction model, the apparent activation energy of SD phase separation was estimated by the Arrhenius equation. In view of its simplicity and sensitivity of measurement, affordability and availability of instrument, and wide application range of polymer blends, RLS proved to be an effective means for characterization of microstructural variation in polymer blends.

MnO(2) as one of the most promising candidates for electrochemical supercapacitors has attracted much attention because of its superior electrochemical performance, low cost, and environmentally benign nature. In this Letter, we explored a novel route to prepare mesoporous MnO(2)/carbon aerogel composites by electrochemical deposition assisted by gas bubbles. The products were characterized by energy-dispersive spectrometry (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The MnO(2) deposits are found to have high purity and have a mesoporous structure that will optimize the electronic and ionic conductivity to minimize the total resistance of the system and thereby maximize the performance characteristics of this material for use in supercapacitor electrodes. The results of nitrogen adsorption-desorption experiments and electrochemical measurements showed that these obtained mesoporous MnO(2)/carbon aerogel composites had a large specific surface area (120 m(2)/g), uniform pore-size distribution (around 5 nm), high specific capacitance (515.5 F/g), and good stability over 1000 cycles, which give these composites potential application as high-performance supercapacitor electrode materials.

A novel ordered mesoporous carbon with an interconnected channel structure (OMC-IC) has been successfully fabricated by adding proper hydrophilic SiO(2) nanoparticles to the solution of triblock copolymer F127 and phenol-formaldehyde resol. Experimental results show that the presence of SiO(2) nanoparticles does not hamper the self-assembly of F127 and resol to form an ordered two-dimensional hexagonal mesostructure. The neighboring channels of the OMC-IC are interconnected after removing SiO(2) nanoparticles with a diameter larger than the thickness of the carbon wall. Such an interconnectivity of channels is beneficial in improving ion diffusion properties. The as-prepared OMC-IC exhibits much lower impedance to ion transport within both the channels and the micropores in the carbon wall, and thus has better electric double layer performance as compared to the conventional OMC with an unconnected channel structure.

In this paper, the feasibility of using carbon aerogels (CAs) as bed electrodes in a three-dimensional electrode reactor for the electrochemical treatment was studied. It was found that the removal efficiency depended on the airflow, the feed phenol concentration, pH, the ratio of aerogels mass to solution volume, and repeated times. Compared with commercial carbon particle electrodes, the CAs prepared exhibited stronger and longer-term activity to remove phenol simulated wastewater. For 250 mg L −1 of phenol solution, 98% of the initial phenol chemical oxygen demand (COD) can be removed after treatment for 20 min. Moreover, high removal efficiency can be kept basically after being reused many times (e.g. 93% and 82% after 20 times and 50 times, respectively).

An activated carbon aerogel with a hierarchical pore structure was prepared through KOH activation with a KOH/organic aerogel with mass ratio 3:1, followed by carbonization at 900 ℃ for 3 h. The activated carbon aerogel was used as a conductive host of elemental sulfur to prepare a composite by a melt-infiltration method. Nitrogen adsorption, SEM, TEM, XRD and XPS were used to characterize the structure and morphology of the samples before and after the sulfur infiltration. Cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy were used to evaluate the electrochemical performance of the composite as a cathode in lithium ion batteries. It is found that the composite has a sulfur content of up to 66.2%, a high initial discharge capacity of 1 287 mAh·g-1 at a current density of 0.2 C and a retained capacity of 643 mAh·g-1 after 200 cycles, which are much higher than those of a sulfur cathode without the carbon host. The composite also exhibits excellent rate capability.

We have prepared carbon aerogels (CAs) doped with cobalt or nickel through sol-gel polymerization of formaldehyde with the potassium salt of 2,4-dihydroxybenzoic acid, followed by ion exchange with M(NO3)2 (where M = Co2+ or Ni2+), supercritical drying with liquid CO2, and carbonization at temperatures between 400 and 1050 degrees C under a N2 atmosphere. The nanostructures of these metal-doped carbon aerogels were characterized by elemental analysis, nitrogen adsorption, high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Metallic nickel and cobalt nanoparticles are generated during the carbonization process at about 400 and 450 degrees C, respectively, forming nanoparticles that are approximately 4 nm in diameter. The sizes and size dispersion of the metal particles increase with increasing carbonization temperatures for both materials. The carbon frameworks of the Ni- and Co-doped aerogels carbonized below 600 degrees C mainly consist of interconnected carbon particles with a size of 15-30 nm. When the samples are pyrolyzed at 1050 degrees C, the growth of graphitic nanoribbons with different curvatures is observed in the Ni- and Co-doped carbon aerogel materials. The distance of graphite layers in the nanoribbons is approximately 0.38 nm. These metal-doped CAs retain the overall open cell structure of metal-free CAs, exhibiting high surface areas and pore diameters in the micro- and mesoporic region.

Copper-doped carbon aerogels, which were prepared by sol-gel polymerization of a mixture of resorcinol, formaldehyde and copper ions, followed by supercritical drying with liquid CO2 and carbonization at different temperatures under a N2 atmosphere, were characterized by magnetic susceptibility and temperature-dependent conductivity measurements. The experimental results show that the magnetic susceptibilities (χ) of all the copper-doped carbon aerogels are larger than that of the blank carbon aerogel. The temperature-dependent magnetic susceptibilities of the copper-doped carbon aerogels are well fit to a Curie function in the low temperature region (below 45 K). According to the Curie constant obtained, the spin concentration (N) of the copper-doped carbon aerogels was calculated and the results show that the spin concentration of doped samples increases at first with an increase in the copper concentration used in doping, and then drops from the maximum in N and χ when the copper concentration is further increased above 0.1 wt%. Magnetic susceptibility results suggest that copper-doped carbon aerogels carbonized at 800 °C are more disordered than those carbonized at 1000 °C. The conductivity of these copper-doped carbon aerogels is apparently higher than that of the blank carbon aerogel, especially at low temperature (T < 45 K). The temperature-dependent resistivities of both the copper-doped and the blank carbon aerogels follow a linear functional form log ρ(T) ∼ (1/T)1/2 with two distinct regions below and above 45 K, indicating that the conduction of both the copper-doped and the blank carbon aerogels obey a tunneling and/or a hopping mechanism.

Constructing three-dimensionally interconnected nanoscale networks is critical for porous materials to achieving enhanced pore accessibility and fast mass transport. Currently, development of facile and effective methods for fabrication of three-dimensional polymeric and carbonaceous networks with a well-defined nanostructure is still challenging. Herein, we present a successful development of a novel class of polymeric and carbonaceous nanoscale networks based on the union of self-assembly and hypercrosslinking. A poly(methyl methacrylate)-b-polystyrene (PMMA-b-PS) diblock copolymer was first self-assembled into uniform PMMA@PS core–shell nanospheres, and then the resulting nanospheres were used as building blocks to construct polymeric nanoscale networks by hypercrosslinking. Due to their hypercrosslinked framework, the as-prepared polymeric nanoscale networks were further transformed into carbonaceous nanoscale networks after carbonization. The resulting nanoporous materials have well-developed three-dimensionally interconnected hierarchical porosity and thus hold great promise in many applications, for example, as CO2 capture materials and as supercapacitor electrodes.

Hollow polymer nanospheres (HPNSs) have received an increased level of attention, not only for their fundamental scientific interest, but also for technological applications. Despite a great deal of research effort, most of the current HPNSs are suffering from a poor polydispersity as well as a particle size larger than 500 nm. Here, we report the synthesis of highly monodisperse hollow microporous polystyrene nanospheres (MHMPNSs) with diameters as low as 120 nm based on a facile hypercrosslinking strategy. We utilize the rapid formation of an almost unreactive crosslinked polystyrene outer skin during the initial hypercrosslinking process, to minimize the undesired inter-sphere crosslinking. Due to the intra-sphere hypercrosslinking, the resulting MHMPNSs possess a well-developed microporous shell structure. The MHMPNSs are able to be used as potential absorbents toward organic vapors, because of their unique hollow core and microporous shell characteristics.

A functional polyacrylic acid (PAA) adsorbent has been prepared for metal chelate affinity chromatography. It has been found to chelate nickel ion Ni2+ strongly, and was evaluated for the ability to bind proteins containing neighbouring histidine residues. The principle of the technique was illustrated with Aeromonas hydrophila outer membrane protein OmpTS. DNA elements coding for adjacent histidines were fused to the Aeromonas hydrophila ompTS gene. Subsequent expression in E. coli resulted in the production of hybrid protein His6-OmpTS that could be purified by Ni2+-PAA affinity chromatography. The remarkable specificity found makes it an attractive addition to the range of adsorbents for metal chelate affinity chromatography.

Abstract -- The copper-doped carbon aerogels were fabricated by ion exchange method. Their structures were investigated by surface area detection, TEM, SEM and XPS. The experimental results showed that the copper-doped carbon aerogels produced have low mass density, a high density of nano-pores and high surface areas. Many copper nano-particles were produced after carbonization of copper-doped carbon aerogels. Before carbonization, part of the copper atoms were reduced into low valence compounds, such as Cu2O.

The ordered 2D reverse hexagonal pore morphology facilitates rapid ion diffusion more than the disordered wormhole-like pore morphology, thus leading to superior electrochemical properties such as rate capabilities.

A very important yet really challenging issue to address is how to greatly increase the energy density of supercapacitors to approach or even exceed those of batteries without sacrificing the power density. Herein we report the fabrication of a new class of ultrahigh surface area hierarchical porous carbon (UHSA-HPC) based on the pore formation and widening of polystyrene-derived HPC by KOH activation, and highlight its superior ability for energy storage in supercapacitors with ionic liquid (IL) as electrolyte. The UHSA-HPC with a surface area of more than 3000 m(2) g(-1) shows an extremely high energy density, i.e., 118 W h kg(-1) at a power density of 100 W kg(-1). This is ascribed to its unique hierarchical nanonetwork structure with a large number of small-sized nanopores for IL storage and an ideal meso-/macroporous network for IL transfer.

A facile route to fabricate nitrogen-doped ordered nanoporous carbons (NONCs) was developed based on in situ polydopamine coating onto the pore surface of ordered nanoporous silica. The NONC exhibits very attractive capacitive properties, including unusually large capacitances up to 538 F g−1, highly efficient electrochemically active surface area and good cycling stability.

Controlling carbon frameworks of nanocarbons from microporous to nonporous without imposing any additional treatment on a given type of precursor currently remains a great challenge. Here, a facile approach for tailoring different pore characteristics of carbon frameworks for nanocarbons from polypyrrole (PPy) precursors has been achieved based on the significant effect of reaction medium on the conjugation degree of PPy chains. Nanocarbon from PPy synthesized in NaOH solution (CPPy-NaOH) has numerous micropores with a BET surface area up to 482 m2 g−1, which is 10-fold higher than that of nanocarbon with an almost nonporous carbon framework from PPy polymerized in HCl solution (CPPy-HCl). This could be attributed to a distinct difference in the conjugation degree of the PPy chains. A much lower conjugation degree for the PPy precursor of CPPy-NaOH facilitates formation of micropores during carbonization. CPPy-NaOH exhibits much higher specific capacitance than CPPy-HCl. Furthermore, CPPy-NaOH gives much larger surface efficiency and higher capacitance retention ratios as compared to a commercial activated carbon for supercapacitors.

A novel type of nanoporous carbon with a 3D nanonetwork-interconnected 2D ordered mesoporous structure is successfully fabricated based on the self-assembly of triblock copolymer F127 and phenol–formaldehyde resol among the nanonetwork from tetraethyl orthosilicate. The as-constructed nanoporous carbons have two unique nanostructure advantages: (1) different from common solid framework for nanonetwork-structured carbons, their carbon framework is made of 2D ordered hexagonal mesopores; (2) unlike isolated mesopores for conventional ordered mesoporous carbons, their neighboring ordered mesopores are interconnected by 3D network-like mesopores. Such a well-defined carbon nanostructure is favorable for fast mass transport, mainly because it can make full use of both the 2D ordered mesoporous structure and the 3D interconnected nanonetwork. The as-prepared nanoporous carbons exhibit great potential as adsorbents toward organic vapor and as electrodes for supercapacitors.

A new class of advanced porous network structured carbon materials exhibits very attractive capacitive properties when utilized as electrodes for organic electrolyte supercapacitors, including large capacitances up to 210 F g−1, unusually high energy densities of 21.4–41.8 W h kg−1 at power densities of 67.5–10 800 W kg−1, and excellent cycling stability.

Copper-series, nickel-series, and copper-cobalt composite-series catalysts supported on activated carbon fiber were prepared in this paper. Their structures and catalytic activities for the reduction of nitric oxide with ammonia were investigated simultaneously.

In order to improve the reduction ability and capacity of ACF, some metal-containing ACF (Me-ACF) were prepared. Their structures and reduction properties were investigated at the same time. On the basis of experimental results, a redox mechanism was proposed.

Hierarchical porous carbons (HPCs) possess a multimodal pore size distribution of micro-, meso-, and/or macropores, and thus show high electrochemically accessible surface area, short diffusion distance, and high mass transfer rate when used as electrode materials in energy storage devices. Because of this, HPCs show excellent rate capabilities and have attracted considerable attention in recent years. Normally, HPCs are prepared by templating methods or combined templating/activation methods, in which carbons are inverse replicas of the template and the pore structure parameters of HPCs can be easily tuned. Recently, simpler template-free methods have been developed and show a promising future. In this review, we describe the recent advances in design, preparation, and electrochemical performance of HPCs, with particular attention to the main achievements using HPCs developed in our groups since 2008. Finally we give a brief Outlook.

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.

A unique hierarchical architecture is successfully constructed in a wormhole-like mesopore structure via a multiple nanocasting route. This novel type of hierarchical porous carbon (HPC) consists of three-dimensional ordered macropores (ca. 150 nm) with interconnecting pore windows, and the walls of these macropores are rich in wormhole-like mesopores (ca. 2.7 nm) and large spherical mesopores (ca. 10 nm), as well as a significant microporosity, presenting a macro-meso-microporous structure with a three-dimensional interconnectivity. Such a hierarchically porous structure may provide fine diffusion pathways for reaction species, which is demonstrated by the experimental result of an enhanced performance in a supercapacitor. For example, with the introduction of a hierarchical porous structure for fast transport and effective access of ions, the as-prepared HPC exhibits a specific capacitance as high as 247 F g(-1), whereas traditional wormhole-like mesoporous carbon has only a specific capacitance of 176 F g(-1).

Hierarchical porous carbon with ultrahigh surface area (i.e., 3350 m2 g−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.

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.

Two typical carbon materials (ordered mesoporous carbon and carbon nanotube) were chosen as scaffolds in combination with semiconductor quantum dots (SQDs) for making light-harvesting assemblies. The effects of interfacial morphology on photoelectric performance of the carbon-based heterostructures have been investigated in detail. The enhanced photoresponse shows a strong dependence on the interfacial morphology as a result of direct interfacial contacts between SQDs and carbon materials, which plays a major role in increasing charge generation at the interface and transport pathways for photoinduced electron transfer. The methodology to enhance the photoresponse through tuning interfacial morphology proves to be a potent alternative in fabricating photochemical energy conversion systems.