Advanced Materials

The front cover illustrates a novel photoconductive nanotube by self-assembly of a dithienylethene-appended hexa-peri-hexabenzocoronene, where the graphite-like nanotubular wall is laminated on both sides by densely packed dithienylethene pendants. The closed form of the photochromic pendant (green) serves as a better electron acceptor than its open form (yellow), so the photoconductivity of the nanotube can be modulated by photochemical isomerization of the pendants. More details can be found in the article by Takuzo Aida and co-workers on p. 829.

The inside cover shows a background SEM image of hierarchical carbon monolith, a swirl of CO₂ molecular models, and two split hemispheres representing the building unit of the carbon framework with abundant porous channels. An-Hui Lu and co-workers report on p. 853 a nitrogen-doped porous carbon monolith with hierarchical pore structures (macroporous and microporous), which show high performance for CO₂ adsorption, making them excellent CO₂ capture materials.

High-quality single-walled carbon nanotube (SWCNT) dispersions are prepared with the aid of novel designed π-surfactants (see figure). Extensive characterization (absorption and emission spectroscopy, zeta-potential measurements, statistical atomic force microscopic analysis) is used to shed light on the dispersion efficiency and to establish structure–property relationships of the SWCNT–surfactant complexes.

Acetylenic scaffolding provides access to a diversity of planar, macrocyclic all-carbon π-chromophores, which include perethynylated dehydroannulenes, perethynylated expanded radialenes, and radiaannulenes and are potent electron acceptors. Peripheral substitution with electron donors leads to strongly enhanced optoelectronic properties and increased solubility and stability. Enantiomerically pure alleno-acetylenic macrocycles represent new chiral carbon-rich molecular architectures, featuring outstanding chiroptical responses.

A hydrothermal carbonization process from biomass allows fabrication of various novel carbon-based materials or composites with special chemical and/or physical properties, which have great potential for environmental, catalytic, biochemical, electric, and sensing applications (see figure).

A semiconducting organic nanotube composed of a graphite-like bilayer of columnarly assembled hexabenzocoronene units (see figure) changes its photoconductivity in response to photoisomerization of the photochromic dithienylethene pendants on the surface.

Onionlike mesoporous carbon and carbon–silica nanocomposites with multilayer vesicle structures can be synthesized by an organic–inorganic co-assembly method under hydrothermal conditions in an aqueous emulsion solution (see figure). The nanocomposite vesicles have ordered lamellar mesostructures with about 3–9 layers and carbon pillars are located between the neighboring shells.

Nanographene-constructed hollow carbon spheres (NGHCs) are fabricated using discotic nanographene as a building block and a silica/space/mesoporous silica sphere as a template. The resultant NGHCs exhibit uniform size and consist of dual walls. In the exterior walls of the NGHCs, nanochannels arrange perpendicularly to the surface, which is favorable for lithium ion diffusion from different orientations, while the interior graphitic solid walls can facilitate the collection and transport of electrons. The NGHCs show excellent electrochemical performance when used as anode material for lithium ion batteries.

Fluorescent nanodiamonds (FNDs) of 10–20 nm in size have been produced by helium ion irradiation and isolated by differential centrifugation. Spectroscopic characterization of the FNDs with fluorescence microscopy and fluorescence correlation spectroscopy indicates perfect photostability and use as an alternative to far-red fluorescent proteins for biolabeling and fluorescence resonance energy transfer applications.

Films of pyridinol-functionalized single-walled carbon nanotubes (SWNTs) exhibit strong electrical response to HCl and in situ optical and electrical measurements reveal that the acid–base equilibrium couples to the oxidation of the SWNTs, inducing electron transfer from the semiconducting SWNTs upon protonation of the pyridine group.

A polymer gel derived from resorcinol and formaldehyde can be prepared in around 5 min using lysine as polymerization catalyst and nitrogen source. After pyrolysis of this polymer gel, a new type of nitrogen-containing carbon monolith was obtained (see figure), which exhibits the highest CO₂-adsorption capacity to date of up to 3.13 mmol g⁻¹ at room temperature.