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The quantification of electron beam damage in crystalline porous materials has been investigated under low-dose electron irradiation conditions.

We demonstrate an unusual crystal-structure transition from metal–organic frameworks (MOFs) composed of ortho-phthalate ligands.

Various hetero-elements were combined with porous SnO2 spheres simply by adding hetero-element sources to the precursor solutions of optimized synthetic conditions.

We demonstrate that the nanosize effect of a host matrix appears to affect the emission properties of guest dye molecules encapsulated in the pores of a metal–organic framework as a host (dye@MOF).

The application scope of metal-organic frameworks (MOFs) can be extended by rationally designing the architecture and components of MOFs, which can be achieved via a metal-containing solid templated strategy. However, this strategy suffers from low efficiency and provides only one specific MOF from one template. Herein, we present a versatile templated strategy in which organic ligands are weaved into hydrogen-bonded organic frameworks (HOFs) for the controllable and scalable synthesis of MOF nanotubes. HOF nanowires assembled from benzene-1,3,5-tricarboxylic acid and melamine via a simple sonochemical approach serve as both the template and precursor to produce MOF nanotubes with varied metal compositions. Hybrid nanotubes containing nanometal crystals and N-doped graphene prepared through a carbonization process show that the optimized NiRuIr alloy@NG nanotube exhibits excellent electrocatalytic HER activity and durability in alkaline media, outperforming most reported catalysts. The strategy proposed here demonstrates a pioneering study of combination of HOF and MOF, which shows great potential in the design of other nanosized MOFs with various architectures and compositions for potential applications.

The rational design and synthesis of frame-like hollow structures with unique three-dimensional open architectures for their diverse applications is still challenging. We herein propose a facile anisotropic surface modification and etching strategy for the synthesis of hollow structured ZIF-67 nanoframes. Our strategy relies on the structural and compositional distinctions between each crystallographic facet of truncated rhombic dodecahedrons ZIF-67 (tZIF-67 RDs) and the moderate coordinating and etching effects of cyanuric acid (CA). Thereby, the CA can anisotropically modify and protect the {110} facets from etching, causing the six {100} facets be selectively etched via an inside-out manner, and finally forming the hollow nanoframes. Interestingly, the surface modified hollow tZIF-67 RDs can further be facet-selectively etched by metal salts via an outside-in manner to give metal-doped tZIF-67 nanoframes. After calcination in reducing atmosphere, the metal-tZIF-67 hydrids are converted into metal-Co alloy/C composite catalysts with hollow nanoframed structures. Among them, the PtCo/C catalyst with only 5.9 wt.% Pt exhibits high catalytic activities and stabilities in the hydrogen evolution reaction (HER) in acidic solutions, outperforming the commercial 20 wt.% Pt/C catalyst. Our results offer insight into the development of metal-organic frameworks with compositional and structural multiplicity, which in turn could encourages more practical catalytic applications.

Porous ceria was obtained using a unique solvothermal reaction in acetonitrile, applying high temperature and pressure. The resulting material comprised homogeneous and monodisperse spheres and exhibited an extremely large surface area of 152 m2 g−1. From catalytic performance evaluation by vapor- and liquid-phase reactions, the synthesized porous ceria showed superior and different reaction activity compared with commercial CeO2. To examine the origin of the reaction activity of the present porous ceria, synchrotron hard X-ray photoelectron spectroscopy (HAXPES) measurements were carried out. The systematic study of HAXPES measurements revealed that the obtained porous ceria with the present solvothermal method contained a very high concentration of Ce3+. Moreover, O2-pulse adsorption analyses demonstrated a significant oxygen adsorption capacity exceeding 268 μmol-O g−1 at 400 °C owing to its high contents of Ce3+ species.

An unusual crystal phase transition was demonstrated in a zeolitic imidazolate framework with a rigid coordination network. Differential scanning calorimetry and powder X-ray diffraction revealed that nanosizing the crystal structure was crucial for the phase transition at low temperature. The thermodynamic parameters of the phase transition were determined by calorimetry.

Submicron-sized niobia (Nb2O5) porous spheres with a high specific surface area (300 m2 g−1) and nano concave–convex surfaces were synthesized via a rapid one-pot single-step alcothermal reaction. Prolonged reaction time or high reaction temperatures resulted in a morphology change of Nb2O5 from amorphous sphere to rod crystals with hexagonal crystal phase. A similar alcothermal reaction yielded TiO2–Nb2O5 composite porous spheres, whose Ti : Nb molar ratio was controlled by changing the precursor solution component ratios. A simple thermal treatment of amorphous TiO2–Nb2O5 porous spheres consisting of 1 : 2 (molar ratio) Ti : Nb at 600 °C for 2 h induced crystal phase transfer from amorphous to a monoclinic crystal phase of submicron-sized TiNb2O7 porous spheres with a specific surface area of 50 m2 g−1.

Ni nanoparticle catalysts embedded in ZrO

Taking advantages of the high heat tolerance, large specific surface area, and rough surface morphology created by agglomeration of fine primary particles, a solvothermally prepared CeO2 aggregate, SiO2–CeO2 nanocomposite, and TiO2–CeO2 nanocomposite are proposed to be used as sintering-resistant catalyst supports in highly exothermic reactions. Well-dispersed Ru metal catalysts were deposited on support surfaces by the precipitation–deposition method. The methanation of CO2 by H2, which is a highly exothermic reaction, was selected as a probe reaction in order to evaluate the catalytic activity and sintering-resistant capability of Ru catalysts deposited on those prepared supports. As expected, the low temperature (150–200 °C) activity and CH4 production of the Ru catalysts on the prepared CeO2 aggregate and TiO2–CeO2 nanocomposites were better than those on commercial CeO2 aggregates. Moreover, long-term stability (400 °C, 24 h; 50–300 °C, 10 cycles) was also achieved in the catalysts on these prepared supports.

We propose a novel method for the fabrication of CeO2 nanoparticles (NPs) with enhanced heat tolerance. SiO2 was mixed with CeO2 at the nano-level to yield SiO2‒CeO2 NP composites by a solvothermal reaction of precursor solutions consisting of Si(OEt)4, Ce(NO3)3·6H2O, and N,N,N′,N′-tetramethylethylenediamine in methanol. SiO2 content in the SiO2‒CeO2 NP composites was freely controllable by adjusting the Si(OEt)4 mol fraction in range of 0–0.5 in the precursor solutions. With an increase of SiO2 content in the SiO2‒CeO2 NP composites, the primary particle sizes of the CeO2 NPs decreased, and the specific surface areas of the SiO2‒CeO2 NP composites increased remarkably. For SiO2‒CeO2 NP composites obtained from a precursor solution consisting of 1:1 Si(OEt)4 and Ce(NO3)3·6H2O, the specific surface area was over 300 m2/g. Excellent heat tolerance was achieved through the retention of small size of CeO2 crystallites, as well as the large specific surface areas of the SiO2‒CeO2 NP assemblies, even after calcination at 850 °C for 3 h or at 700 °C for 72 h in air.

Mesoporous spherical aggregates of Nb-doped anatase TiO2 nanoparticles were synthesized by a simple one-pot solvothermal method in supercritical methanol and were evaluated as anode materials for L...

Porous ceria was obtained using a unique solvothermal reaction in acetonitrile, applying high temperature and pressure. The resulting material comprised homogeneous and monodisperse spheres and exhibited an extremely large surface area of 152 m

A characteristic effect of a nano-concave-convex structure of a zirconia nanoparticle assembly with an inherent porous structure and huge surface area enabled us to introduce systematic surface modification by thermal treatment to smooth surface and polymer impregnation to mask the nano-concave-convex structure of the zirconia nanoparticle assembly. A polymer composite prepared from 30 wt% poly(N-isopropylacrylamide) containing 0.02 wt% zirconia nanoparticle assembly with the inherent nano-concave-convex surface structure showed the highest tensile strength in mechanical tensile testing. However, both sintered zirconia nanoparticle assembly with smooth surface and zirconia nanoparticle assemblies with polymer masked surface showed lower strength with longer elongation at break in mechanical tensile testing.

Ultrafine titania nanocrystals were synthesized using a rapid heating, one-pot solvothermal method. These nanocrystals are extremely small with a narrow size distribution (3.0 ± 0.4 nm). The detailed structural analysis by using transmission electron microscopy reveals periodic alignment of the resultant titania nanocrystals with hexagonal symmetry due to their size uniformity. The drop-casting deposition and calcination of these nanocrystals are also enable to convert into mesoporous thin layer films with nano convex-concave surface. The resultant transparent mesoporous thin layer exhibits not only anti-reflection properties but also high photocatalytic activity.

A single-step synthetic method was developed to obtain ultrafine MgO nanocrystals by ultimately simple solvothermal treatment of a precursor solution containing magnesium acetylacetonate in acetonitrile at 400 °C for 10 min. HRTEM images and calculations based on Scherer equation showed that the average size of obtained ultrafine MgO nanocrystals was ca. 7 nm.

Non-thermal helium atmospheric pressure plasma jet treatment is applied to the surface activation of porous TiO2 nanoparticle assemblies. Treatment conditions such as the working distance of the plasma discharge, helium gas flow rate, and treatment time are optimized for effective removal of contaminants from the assembly surface. Laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) is applied to detect trace amounts of contaminants on assembly surfaces. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations confirm that the nanoparticle assemblies retain their original perfect spherical structures as well as their ultra-fine convex-concave nano-surfaces even after the plasma jet treatment. N2 adsorption/desorption and X-ray diffraction (XRD) measurements show no significant changes in their BET specific surface areas and crystal structures, respectively. The plasma jet-treated TiO2 nanoparticle assemblies show a 3.8 fold improvement in their reaction rate constants for methylene blue degradation and a 2 fold enhancement of their photocurrents under UV irradiation when compared with untreated TiO2.

The characteristics of nano-fillers in a polymer matrix have a significant influence on the microstructural, thermo-mechanical, optical, and conductivity properties of organic-inorganic nanocomposites. In this study, we investigated the influence of inorganic component – ZnO nanoparticles (NPs) on the characteristics and properties of PVA-ZnO nanocomposites which have been applied as an insulation layer in a resistive switching (RS) device. Three nanocomposites originating from three different types of ZnO NPs exhibit different RS characteristics: Abnormal volatile RS is observed with the ∼20-nm-sized spherical-like NPs (Z1) and 15–20-nm-sized mixed shaped NPs (Z2), whereas normal nonvolatile bipolar RS is observed with the 50–150-nm-sized hexagonal rod-like NPs (Z3). The concentration and size of the intrinsic defects of the ZnO NPs as well as the thickness of the PVA-ZnO interface are responsible for the different charge transport paths, operating voltage ranges, and ON/OFF switching ratios of the memory devices. Simultaneously, the distinct sizes and morphologies of the ZnO NPs can affect the nanoholes among the PVA chains and induce various fractional free volumes in the nanocomposites. It may modify the conductivity of the nanocomposite layer or the resistance ratio of the memory devices. Understanding the influence of ZnO NPs size, morphology, and defects on the characteristics of RS of PVA-ZnO nanocomposites can help in the selection and management of functional applications, especially in the data storage field.

Nanofiber bundles of TiO2 with a unique cheek-brush morphology were prepared by simple, rapid, one-pot, single-step, and template-free solvothermal treatment of a titanium alkoxide and aromatic ester in methanol. The solvothermal reaction was performed by heating a mixture of titanium tetraisopropoxide and dimethyl phthalate in methanol to 300 °C. The precursor solution had to be kept at room temperature for 20 min before heating the solution to obtain a cheek-brush morphology. The heating rate (5–6 °C/min), final reaction temperature (300 °C), and holding time at the final temperature (10 min) were also crucial for formation of the cheek-brush morphology. A systematic study of additives in the precursor solution showed that aromatic esters such as diethyl phthalate and methyl benzoate gave cheek-brush morphologies. The cheek-brush TiO2 assemblies were used to crosslink a poly(N-isopropylacrylamide) hydrogel; the brushes enhanced the physical adhesion properties of the hydrogel. The hydrogel prepared from a 20wt% polymer containing 0.02wt% of the cheek-brush TiO2 assemblies had an 11 % and 9.1 % higher ultimate tensile strength and elongation ability, respectively, compared with a prototype hydrogel without a crosslinker. A hydrogel prepared using TiO2 spheres of a similar size had an 11 % and 18 % lower ultimate tensile strength and elongation ability, respectively, compared with the prototype hydrogels.

Five novel surfactants were prepared by modifying the three hydroxy groups of sodium cholate with triethylene glycol chains endcapped with an amide (SC-C1 , SC-n C4 , and SC-n C5 ) or a carbamoyl group (SC-On C4 and SC-Ot C4 ). The phase behavior of aqueous mixtures of these surfactants with 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) was systematically studied by 31 P NMR spectroscopy. The surfactants endcapped with carbamate groups (SC-On C4 and SC-Ot C4 ) formed magnetically alignable bicelles over unprecedentedly wide ranges of conditions, in terms of temperature (from 21-23 to >90 °C), lipid/surfactant ratio (from 5 to 8), total lipid content (5-20 wt %), and lipid type [DMPC, 1,2-dilauroyl-sn-glycero-3-phosphatidylcholine (DLPC), or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC)]. In conjunction with appropriate phospholipids, the carbamate-endcapped surfactants afforded unique bicelles, characterized by exceptional thermal stabilities (from 0 to >90 °C), biomimetic lipid compositions (DMPC/POPC=25:75 to 50:50), and extremely large 2 H quadrupole splittings (up to 71 Hz).

A millimeter-long metal–organic framework fiber has been successfully constructed. The fiber structure was unexpectedly found via the solvent vaporization process of a dispersion of a Zn-based MOF crystal. Detailed experiments and structural analysis indicate that a humid environment is a key to the growth of the fiber structure, inducing drastic transformation of the MOF crystal morphology from the nanoscopic to macroscopic scale. Synchrotron X-ray single-crystal diffraction analysis reveals that the complete crystal transformation from the Zn-MOF sheet to Zn-MOF fiber is accompanied by water coordination and ligand rearrangement. The highly anisotropic MOF fiber is easily converted to an electro-conductive fiber while maintaining the long-fiber morphology.

A simple synthetic approach to Al2O3–TiO2 and ZnO–TiO2 mesoporous hollow composite assemblies consisting of homogeneously mixed primary particles at the nano scale was demonstrated. The composites, Al2O3–TiO2 and ZnO–TiO2, have a large specific surface area (250–600 m2 g–1) and were synthesized by high-temperature and high-pressure treatment of precursor solutions containing Al(OiPr)3 or Zn(OAc)2, Ti(OiPr)4, and phthalic acid in methanol. Aggregated, fused spherical, and individual spherical morphologies of the hollow assemblies with amorphous Al2O3 and anatase TiO2 were obtained, depending on the Al/Ti ratio of the precursor solutions. Hollow spherical composite assemblies with amorphous ZnO and anatase TiO2 phases were obtained by treating precursor solutions with lower Zn contents (5–25 %). A phase transition from anatase to rutile was not observed for the Al2O3–TiO2 composite assemblies (50 % Al) even at 1000 °C. The band gap energies of the ZnO–TiO2 hollow assemblies were tuned (3.12–3.21 eV) by changing their Zn content.

In this study, a novel hydrothermal route has been developed for the synthesis of MoS2/graphene composite with controllable structures, in which ammonium molybdatetetrahydrate, as-prepared graphene oxide (GO), and thioacetamide were used as staring materials. Effects of Mo4+-to-C precursor ratios and crystalline time on the structures, components and morphologies of MoS2/graphene were investigated. MoS2/graphene samples were characterized using XRD, FESEM, HRTEM, FTIR, Raman spectroscopy, HAADF-STEM/EDS, HXPES and electrical measurements. The results show that petal-like MoS2 nanostructures with ultrathin petals (~1–10 layers) and coexistence of 1T- and 2H-MoS2 phases can be synthesized on graphene surface in a short time (~2 h). Comparison of crystallization conditions, we found that the crystallization time had a significant effect on the size of the MoS2 nanopetals. The shorter the reaction time is, the thinner the petal-like MoS2 nanoscale is. On the other hand, by adjusting the ratios of Mo4+to C (denoted as: MoS2/C (1:2), MoS2/C (3:2), MoS2/C (2.5:1) and MoS2/C (3:1)), different MoS2/graphene architectures including “sandwich-liked”, “layer–by–layer” and “anchored” can be obtained. On the basis of these results, a possible growth mechanism of MoS2nanopetals on GO was proposed. Interestingly, the as-synthesized material depicts its memristive behavior through the Volt-Ampere characteristics, suggesting a potential application in logic memory devices.

In situ polymerization of a bicellar mixture composed of a phospholipid and polymerizable surfactants afforded unprecedented stable bicelles. The polymerized composite showed an aligned phase over a wide thermal range (25 to >90 °C) with excellent 2H quadrupole splitting of the solvent signal, thus implying versatility as an alignment medium for NMR studies. Crosslinking of the surfactants also brought favorable effects on the kinetic stability and alignment morphology of the bicelles. This system could thus offer a new class of scaffolds for biomembrane models.

Benzhydrol was directly reduced to diphenylmethane by α-hydroxyaldehydes and dialdehyde, being saccharide degradates, without using a hydride reagent, in supercritical water at 400 °C for 10 min. A lower-temperature reaction in subcritical water at 300 °C primarily generated 1,1,2,2-tetraphenylethane. A plausible reaction pathway was proposed, involving radical formation via the degradation of hemiacetal intermediates derived from benzhydrol and aldehydes.

CeO_2-ZrO_2 composite nanoparticles with mesoporous and spherical morphologies were assembled into different homogeneously dispersed, domain, and core-shell structures by changing the reaction conditions, such as the heating rate, acid, and solvent, in supercritical alcohols. Ce_xZr_O_2 with homogeneous structures were prepared from Ce(NO_3)_3 and ZrO(NO_3)_2 in the presence of formic acid in methanol by rapid heating (500℃/min) to 300℃, while CeO_2–ZrO_2 with domain structures were obtained by slow heating (5.4℃/min). Treatment of mesoporous and spherical ZrO_2 nanoparticles with a Ce(NO_3)_3 solution in supercritical conditions yielded CeO_2-ZrO_2 nanocomposites with core-shell morphologies, while solvents playing a key role in controlling the thickness of the outer shell; methanol produced a very thin outer shell (

The ability of a rapid-heating solvothermal process to synthesize porous nanocrystal assemblies composed of the multiple transition metals was demonstrated. The rapid heating facilitated the quick formation of nascent nanocrystals to generate homogeneous mixed transition-metal oxides. Systematic studies of the synthesis of mixed-metal oxides under various experimental conditions indicated that the present simple method is suitable to develop a wide variety of binary and ternary transition-metal systems such as Co/Mn, Ni/Mn, and Co/Mn/Fe mixed-metal oxides. The products obtained from the rapid heating process were hierarchically assembled porous nanospheres composed of sub-10 nm nanocrystals, which had an extraordinarily high surface area and nano/mesopores. Electrochemical tests revealed the high catalytic ability of the porous nanocrystal assemblies in water oxidation.

[a] School of Environmental Science and Engineering, KochiUniversity of Technology,185 Miyanokuchi, Tosayamada, Kami, Kochi 782-8502, JapanE-mail: wang.pengyu@kochi-tech.ac.jpkobiro.kazuya@kochi-tech.ac.jphttp://www.env.kochi-tech.ac.jp/kobiro/external/index.html[b] Center for Collaborative Research, Anan National College ofTechnology,265 Aoki Minobayashi, Anan, Tokushima 774-0017, Japan[c] Surface Physics Group, Surface Physics and Structure Unit,Advanced Key Technologies Division, National Institute forMaterials Science,1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan[d] Synchrotron X-ray Station at SPring-8, National Institute forMaterials Science1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, JapanSupporting information for this article is available on theWWW under http://dx.doi.org/10.1002/ejic.201402646.

A general method to prepare polymer gels containing anisotropically oriented graphene oxide (GO) or reduced graphene oxide (RGO) was developed, by using the magnetically induced orientation of GO. Under a magnetic field, an aqueous dispersion of GO was gelated by in situ cross-linking polymerization of an acryl monomer and a cross-linker. In the resultant hydrogel, the orientation of GO was retained even in the absence of the magnetic field, because the gel network trapped GO via noncovalent interactions and efficiently suppressed the structural relaxation of GO. The locked structure enabled quantitative investigation on the magnetic orientation of GO using 2D small-angle X-ray scattering, which revealed that GO nanosheets orient parallel to the magnetic field with an order parameter of up to 0.80. Systematic studies with varying gelation conditions indicate that the present method can afford a wide range of GO-hybridized anisotropic materials, in terms of GO alignment direction, sample shape, and GO concentration. Also by virtue of the locked structure, the orientation of GO in the hydrogel was well preserved throughout the in situ chemical reduction of GO, yielding an RGO-hybridized anisotropic hydrogel, as well as the conversion of the hydrogel into organo- and ionogels through the replacement of the internal water with solvents. As a preliminary demonstration of the present method for practical application, a polymer-composite film containing RGO oriented vertical to the film surface was prepared, and its anisotropically enhanced electroconductivity along the orientation direction of RGO was confirmed by the flash-photolysis time-resolved microwave conductivity measurement.

Novel clay–polymer composite hydrogels with high water content (up to 98 wt %) are developed, in which mechanical properties are reinforced by the formation of multiple ion-pairs between the polymer chains and clay nanosheets (CNS). When a small amount of guanidinium-pendant methacrylamide (0.1–0.2 wt %) is copolymerized with a neutral monomer (0.5–2.0 wt %) in an aqueous dispersion of CNS (1.0–3.0 wt %), a self-standing hydrogel with satisfactory mechanical toughness and elasticity results, despite its high water content (95–98 wt %). The mechanical properties and swelling behaviors of the hydrogels can be tuned by the amount of the guanidinium-pendant acrylamide. A systematic study indicates that the ion pairs, formed between the guanidinium groups in the polymer chains and the oxyanions on the surfaces of the CNS, serve as crosslinking points in the three-dimensional network developed in these hydrogels. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 839–847

Cup-shaped nanocarbons and fullerene (C60) have been successfully organized as composite nanoclusters by using a rapid solvent mixing method. The resulting clusters were assembled on the nanostructured SnO2 electrode for photoelectrochemical measurements. This composite cluster film electrode afforded the drastic enhancement in the photoelectrochemical performance as well as the broader photoresponse in the visible region as compared with the reference system containing C60 cluster because of the efficient electron transport ability of cup-shaped nanocarbons. This makes cup-shaped nanocarbon materials a promising candidate for developing efficient photoelectrochemical and photovoltaic cells.

Porphyrin-functionalized cup-shaped nanocarbons (CNC-H2P) have been assembled onto nanostructured SnO2 films using an electrophoretic deposition method to examine the photoelectrochemical properties. The obtained CNC-H2P nanohybrid films were examined by a series of steady-state and time-resolved spectroscopic measurements and photoelectrochemical measurements. The resulting nanohybrid film afforded drastic enhancement in the photoelectrochemical performance as well as broader photoresponse in the visible region as compared with the reference CNC system without porphyrins. The enhancement of photocurrent generation may be caused by the efficient electron injection from the long-lived charge-separated state of CNC-H2P upon photoexcitation. This feature makes cup-shaped nanocarbon materials a useful candidate for developing efficient photoelectrochemical and photovoltaic cells.

Cup-shaped nanocarbons (CNC) generated by the electron-transfer reduction of cup-stacked carbon nanotubes have been functionalized with porphyrins (H(2)P) as light-capturing chromophores. The resulting donor-acceptor nanohybrid has been characterized by thermogravimetric analysis (TGA), Raman and IR spectroscopy, transmission electron microscopy, elemental analysis, and UV/Vis spectroscopy. The weight of the porphyrins attached to the cup-shaped nanocarbons was determined as 20% by TGA and elemental analysis. The UV/Vis absorption spectrum of CNC-(H(2)P)(n) in DMF agrees well with that obtained by the superposition of reference porphyrin (ref-H(2)P) and cup-shaped nanocarbons. The photoexcitation of the CNC-(H(2)P)(n) nanohybrid results in formation of the charge-separated (CS) state to attain the longest CS lifetime (0.64+/-0.01 ms) ever reported for donor-acceptor nanohybrids, which may arise from efficient electron migration following the charge separation. The formation of a radical ion pair was detected directly by electron spin resonance (ESR) measurements under photoirradiation of CNC-(H(2)P)(n) with a high-pressure mercury lamp in frozen DMF at 153 K. The observed ESR signal at g = 2.0044 agrees with that of ref-H(2)P(*+) produced by one-electron oxidation with [Ru(bpy)(3)](3+) in deaerated CHCl(3), indicating the formation of H(2)P(*+). The electron-acceptor ability of the reference CNC compound (ref-CNC) was also examined by the electron-transfer reduction of ref-CNC by a series of semiquinone radical anions.

SiO2–TiO2 composite nanoparticle assemblies with or without alkyl surface modification and bearing a higher-order hollow spherical morphology were successfully synthesized by a simple, rapid, one-pot, and single-step solvothermal method using a precursor solution consisting of n-octyl-Si(OMe)3 or Si(OEt)4, Ti(OiPr)4, o-phthalic acid, and acetic acid in methanol. The addition of acetic acid is essential for a high yield of nanoparticle assemblies with hollow spherical morphology and a high content of Si. The Si/Ti atomic ratio in the SiO2–TiO2 composite nanoparticle assemblies was easily controlled by changing the Si/Ti atomic ratio in the precursor solutions. The TiO2 nanoparticles exhibited good dispersibility in a polar solvent (methanol), while the n-octyl-modified SiO2–TiO2 composite nanoparticle assemblies were readily dispersed in a nonpolar solvent (toluene). Thus, the hydrophilic–lipophilic balance of the SiO2–TiO2 nanoparticle assemblies with hollow spherical morphology was directly controlled by the one-pot and single-step solvothermal method.

The photoinduced electron-transfer reduction of cup-stacked carbon nanotubes (CSCNTs) with 1-benzyl-1,4-dihydronicotinamide dimer [(BNA)2] results in the electrostatic destacking of CSCNTs to afford CSCNTs with uniform size.

ABA-triblock copolyethers 1a-1c as linear polymeric binders, in combination with clay nanosheets (CNSs), afford high-water-content moldable supramolecular hydrogels with excellent mechanical properties by constructing a well-developed crosslinked network in water. The linear binders carry in their terminal A blocks guanidinium ion (Gu(+)) pendants for adhesion to the CNS surface, while their central B block comprises poly(ethylene oxide) (PEO) that serves as a flexible linker for adhered CNSs. Although previously reported dendritic binder 2 requires multistep synthesis and purification, the linear binders can be obtained in sizable quantities from readily available starting materials by controlled polymerization. Together with dendritic reference 2, the modular nature of compounds 1a-1c with different numbers of Gu(+) pendants and PEO linker lengths allowed for investigating how their structural parameters affect the gel network formation and hydrogel properties. The newly obtained hydrogels are mechanically as tough as that with 2, although the hydrogelation takes place more slowly. Irrespective of which binder is used, the supramolecular gel network has a shape memory feature upon drying followed by rewetting, and the gelling water can be freely replaced with ionic liquids and organic fluids, affording novel clay-reinforced iono- and organogels, respectively.

A donor-acceptor nanohybrid composed of single-walled carbon nanotubes (SWNTs) and coenzyme Q(10) (CoQ(10)) undergoes efficient photoinduced electron transfer from SWNT to CoQ(10) to produce the charge-separated state as indicated by femtosecond laser flash photolysis and ESR measurements.

The electron-transfer reduction of cup-stacked carbon nanotubes (CSCNTs) with sodium naphthalenide and the subsequent treatment with 1-iodododecane results in electrostatically destacking of CSCNTs to afford cup-shaped carbons with controlled diameter and size. The dodecylated cup-shaped carbons were highly dispersed and stable in nonpolar solvents, such as THF, tetrachloroethylene, and chloroform, as compared with the pristine CSCNTs.