We report on an easy synthesis method for the preparation of a hybrid composite of Pt-loaded MWCNTs@MOF-5 [Zn4O(benzene-1,4-dicarboxylate)3] that greatly enhanced hydrogen storage capacity at room temperature. To prepare the composite, we first prepared Pt-loaded MWCNTs, which were then incorporated in-situ into the MOF-5 crystals. The obtained composite was characterized by various techniques such as powder X-ray diffractometry, optical microscopy, porosimetry by nitrogen adsorption, and hydrogen adsorption. The analyses confirmed that the product has a highly crystalline structure with a Langmuir specific surface area of over 2000 m2/g. The hybrid composite was shown to have a hydrogen storage capacity of 1.25 wt% at room temperature and 100 bar, and 1.89 wt% at cryogenic temperature and 1 bar. These H2 storage capacities represent significant increases over those of virgin MOF-5s and Pt-loaded MWCNTs.

Despite that metal organic frameworks (MOFs) have been considered as an effective hydrogen adsorbent, there has been little systematic information available on the effect of synthetic parameters on the evolution of structural features such as crystal structure and pore characteristics and further on hydrogen storage capacity of MOFs. We, therefore, carried out a systematic study to find the effects of the synthetic conditions on the evolution of crystal structure, pore characteristics, and hydrogen storage capacities of MOF-5s through both experimental and computational studies. We found that the precursor concentration had a noticeable influence on the degree of interweaving in the MOF-5s: high concentrations favored interwoven crystal forms, whereas low concentrations favored noninterwoven crystal forms. This variation has led to a substantial difference in the pore characteristics. Since the interweaving reduced pore volume and constricted pore dimensions, the Langmuir specific surface areas of the MOF-5s decreased from 2696 to 1006 m2/g, with concurrent evolution of ultramicroporosity. Moreover, the changes in the pore characteristics have significantly affected the hydrogen storage capacities of the product. Cryogenic hydrogen storage capacity at 1 bar of the interwoven MOF-5s was enhanced from 1.03 wt % (noninterwoven MOF-5) to 1.76 wt % due to highly developed ultramicroporosity. Our results indicate that this simple but efficient concentration controlled synthesis method not only provides highly interwoven and/or noninterwoven MOF-5s but also allows a control of the pore characteristics and H2 storage capacity of MOF-type materials. The understanding of this correlation is particularly useful to establish favorable synthetic criteria for the preparation of MOF-type materials with rational designs.

In this work, we synthesized a novel perylene tetracarboxylic acid diimides derivative (APBI-G) which shows a strong self-assembling tendency to the semiconducting nano/microwires based on the augmented intermolecular hydrogen bonding interaction. We demonstrate the spinning of continuous thread of APBI-G from the liquid–liquid interface and also the fabrication of patterned nano/microwire arrays using MIMIC (micromolding in capillaries) method. MIMIC-fabricated APBI-G nano/microwires showed the excellent uniaxial orientation, large birefringence, and reproducible electrical conductivity (1.93 ± 0.47 × 10−6 S cm−1).

We developed a very simple, template-free, and environmentally friendly one-step chemical synthesis route to fabricate unagglomerated polypyrrole (PPy) nanospheres. The proposed new fabrication method enables the production of size-controlled unagglomerated PPy nanospheres without the help of any supporting materials such as “hard” and “soft” templates and under mild conditions, viz., room temperature, atmospheric pressure, and no need for acid. From the theoretical calculation, we could find that our novel system was suitable to prepare the unagglomerated PPy spheres. The process is discussed on the basis the classical colloidal and microemulsion theory.

1-D carbon nanomaterials were prepared by a novel catalyst-free and template-free synthesis based on the carbonization of in situ formed fibrous polymer precursors. The products had ribbon-like shapes and a mean diameter of ∼40 nm. The proposed method is simple, inexpensive, and environmentally friendly, and yields promising candidate materials for applications such as electrostatic dissipation and touch screens.

Metal−organic frameworks (MOFs) are a rapidly growing class of microporous materials. Various MOFs with tailored nanoporosities have recently been developed as potential storage media for natural gases and hydrogen. However, wider applications have been limited because even atmospheric moisture levels cause MOF instability, and unexpectedly low H2 storage capacity, at 298 K. To overcome these problems, we synthesized a hybrid composite of acid-treated multiwalled carbon nanotubes (MWCNTs) and MOF-5 [Zn4O(bdc)3; bdc = 1,4-benzenedicarbocylate] (denoted MOFMC). In a successful synthesis, well-dispersed MWCNTs in dimethylformamide (DMF) were mixed with a DMF solution of zinc nitrate tetrahydrate and terephthalic acid. The MOFMCs obtained had the same crystal structure and morphology as those of virgin MOF-5, but exhibited a much greater Langmuir specific surface area (increased from 2160 to 3550 m2/g), about a 50% increase in hydrogen storage capacity (from 1.2 to 1.52 wt % at 77 K and 1 bar and from 0.3 to 0.61 wt % at 298 K and 95 bar), and much improved stability in the presence of ambient moisture.

The development of one-dimensional fluorescent nanowires (1D-NWs) and their higher-dimensional architectures such as nanowebs and nanofabrics (2D-NFs) could open a new area in nanomaterials science and nanotechnology. In particular, fluorescent π-electronic 1D-NWs are considered promising materials for realizing innovative nanodevices together with semiconductors and metallic NWs. We earlier reported that 1-cyano-trans-1,2-bis-(3′,5′-bis-trifluoromethyl-biphenyl)ethylene (CN-TFMBE), a simple but very peculiar derivative of oligo(p-phenylene vinylene)s (OPV) composed of a cyano-stilbene backbone, self-assembles easily into 1D-NWs with highly enhanced fluorescence emission in the solid state. We report herein surprising new outcomes obtained from a more detailed exploration of the self-association behavior of CN-TFMBE and its analogues. We found that CN-TFMBE self-assembled into highly fluorescent 1D-NWs and 2-D NFs very easily and massively, irrespective of whether drop casting, spin coating, or vacuum deposition was used for processing. However, we additionally found that, if the backbone cyano group or trifluoromethyl substituents were removed from CN-TFMBE, the resulting molecule did not form 1D-NWs under any conditions. Through structural analyses using mid- and wide-angle X-ray diffraction methods and multiscale computer simulation techniques, we formulated molecular structural guidelines for programming π-electron molecules into highly fluorescent 1D-NWs and 2-D NFs. Interestingly, we demonstrated that R,G,B,Y-color tuned 1D-NWs and NFs could be easily and massively fabricated based on our guidelines. This class of highly fluorescent color-tuned organic π-electronic nanomaterial is expected to open a new phase in applications such as nanoscale optoelectronics, sensing, and biological devices.

A brief review on spherical carbons, including fullerenes and related spherical particles, is first provided, followed by a review of the results on air activation, porosity and applications focused on glass-like carbon spheres derived from phenolic resin spheres. Kinetic studies of the oxidation in air provide a fundamental understanding of activation process of glass-like carbon spheres. On the basis of the results, a new activation procedure, viz. two-step activation, is proposed, which provides ca. 10% higher oxidation yield in obtaining a comparative pore structure. Some possibilities for applications of these glass-like carbon spheres are also described, such as the adsorption/desorption of CO2 gas and chlorinated methanes, the adsorption of organic molecules from their aqueous solutions, and the provision of electrodes for electric double layer capacitors and lithium ion rechargeable batteries.

This study reports the dual-functions of ferrous sulfate, i.e. as a carbon-yield-enhancer and as a pore-size-controller, in the preparation of porous carbons from rice straws. Through the impregnation of rice straws with 0.5 M aq. FeSO4, the carbon yield of the resultant porous carbons increased by ca. 10% and the size of the newly created pores was precisely controlled at the diameter of 0.53 nm during carbonization process. The observed results were discussed from the view points of the thermal degradation mechanism of cellulose and the pillar effects by the in-situ formed crystallites of Fe3O4. The inherent magnetic property due to the presence of magnetite, Fe3O4, was an additional merit of the obtained porous carbons.

We report a new method that enables the facile synthesis of monodisperse zinc oxide (ZnO) quantum dots (QDs) with high quality photoluminescence (PL) characteristics. In the proposed method, ZnO QDs are grown on acid-treated multiwalled carbon nanotubes (a-MWCNTs) under remarkably mild reaction conditions (low temperature, short time, atmospheric pressure, and no need for subsequent thermal annealing). The ZnO QDs grown on the a-MWCNTs were monodisperse and highly crystalline, and had diameters of about 7 nm. Moreover, the a-MWCNT-grown ZnO QDs exhibited a definitive blue emission without defect-related blue–green emission, features that are indicative of definite quantum confinement effects and high quality.

To find a novel high-performance anode material for lithium-ion batteries, a new form of carbon characterized by highly crimped and crystalline nanofibrillar microtextures was produced by heat treating polyacrylonitrile/FeCl3 hybrid precursor and subsequent thermal annealing under hydrogen gas. This form of carbon exhibits a rechargeable capacity of ∼630 mAh/g, which is superior to that of graphite, with a Coulomb efficiency of ∼70%. Further, the new form of carbon was found to exhibit an efficiency of lithium ion insertion/extraction of ∼100% in the voltage range from 0.06 to 0.80 V, with a capacity of ∼400 mAh/g. We speculate that this excellent capacity is due to the characteristic structure of this form of carbon, i.e. its highly entangled web-like hyperstructure consisting of highly crimped and crystalline nanofibrillar microtextures, which enables good permeation and has high resilience to volume deformation during the insertion/extraction of Li ions.

We have synthesized a novel class of excited-state intramolecular proton transfer-active molecule (DOXG) forming columnar liquid crystals with enhanced fluorescence emission. The intramolecularly H-bonded core of DOXG produced columnar hexagonal and rectangular phases during cooling as a result of strong core-to-core interactions. In its mesophase, DOXG produced tilted stacking (J-type) in the inner column due to the elliptical molecular shape, bringing about a strong (quantum yield of 34%) and large Stokes' shifted (173 nm) fluorescence emission.

An amphiphilic diblock copolymer (PEtOz-PCL) based on hydrophilic poly(2-ethyl-2-oxazoline) (PEtOz) and hydrophobic poly(ε-caprolactone) (PCL) was adsorbed in aqueous phase on the surface of single-wall carbon nanotube to produce PEtOz-PCL-encapsulated SWCNTs (PEtOz-PCL/SWCNT) with the diameter about 30 nm. The Raman spectroscopy analysis indicated that the nanotubes were physically encapsulated by the block copolymer without chemical denaturation of the nanotube. PEtOz-PCL/SWCNTs exhibited pH-responsive reversible complexation with poly(acrylic acid) or poly(methacrylic acid) in aqueous phase due to the pH-dependent hydrogen bonding between the PEtOz outer shell of PEtOz-PCL/SWCNTs with carboxyl groups. In addition, by using PEtOz as a template for the formation of metal nanoparticles, Au and Pd nanoparticles were successfully hybridized with PEtOz-PCL/SWCNTs.

Electrochemical capacitors based on RuO2 were prepared onto electrospun TiO2 nanorods. Further heat treatment of the TiO2 at 800 °C under nitrogen was found to greatly improve the electrochemical performance of the RuO2 electrodes, especially at fast charge-discharge rates. The specific capacitance was found to decrease by only 33% when the scan rate increased from 10 to 1000 mV s−1 (from 687 to 460 F g−1). The characteristic response time of the RuO2 electrode was found to be 0.15 s when a heat-treated TiO2 substrate was used, which is 20 times better than that of the pristine TiO2 used.

The geometric effect of graphite nanofibers (GNFs) as a support for PtRu electrocatalysts on the oxidation of methanol for direct methanol fuel cells (DMFCs) was studied using X-ray diffraction, field emission transmission electron microscopy (FETEM) and electrochemical measurements. A high loading of 60 wt% PtRu catalyst, which is readily applicable to DMFCs, was well dispersed on GNFs. Further, the shape of the supported metal particles was affected by interactions with the GNFs. Electrochemical analysis indicated that GNF-supported PtRu catalysts resulted in an increased catalytic activity of about 100% over that of Vulcan XC-72 supported catalysts. FETEM data indicate that the enhanced activities result from a geometric modification of the catalyst particles by specific interactions between the GNFs and the supported PtRu nanoparticles.

Electrodeposition of RuO2 on electrospun TiO2 nanorods using cyclic voltammetry is shown to increase the capacitance of RuO2. This phenomenon can be attributed to the large surface areas of the nanorods. Among several ranges of deposition, the range from 0.25 to 1.45 V with respect to Ag/AgCl was effective. The electrode deposited with this range exhibited a specific capacitance of 534 F g−1 after deposition for 10 cycles with a scan rate of 50 mV s−1. The structural water content in RuO2 was quite different depending on the deposition potential range. Higher amounts of structural water increased the charge storage capability. The stability of the electrode was tested using cyclic voltammetry over 300 cycles.

The tensile-recoil compressional behavior of the carbon nanotube reinforced mesophase pitch (MP)-based composite carbon fibers (CNT-re-MP CFs) was investigated by using Instron and SEM. The CNT-re-MP CFs exhibited improved, or at least equivalent, compressive strength as compared with commercial MP-based carbon fibers. Particularly, when CNT of 0.1 wt% was reinforced, the ratios of recoil compressive strengths to tensile strength of CNT-re-MPCFs were much higher (the difference is at least 10% or higher) than those for the commercial counterparts and even than those for PAN-based commercial carbon fibers. FESEM micrographs showed somewhat different fractography from that of a typical shear failure as the CNT content increased.