Black TiO2 attracts enormous attention due to its large solar absorption and induced excellent photocatalytic activity. Herein, a new approach assisted by hydrogen plasma to synthesize unique H‐doped black titania with a core/shell structure (TiO2@TiO2‐xHx) is presented, superior to the high H2‐pressure process (under 20 bar for five days). The black titania possesses the largest solar absorption (≈83%), far more than any other reported black titania (the record (high‐pressure): ≈30%). H doping is favorable to eliminate the recombination centers of light‐induced electrons and holes. High absorption and low recombination ensure the excellent photocatalytic activity for the black titania in the photo‐oxidation of organic molecules in water and the production of hydrogen. The H‐doped amorphous shell is proposed to play the same role as Ag or Pt loading on TiO2 nanocrystals, which induces the localized surface plasma resonance and black coloration. Photocatalytic water splitting and cleaning using TiO2‐xHx is believed to have a bright future for sustainable energy sources and cleaning environment.

Utilizing solar energy for hydrogen generation and water cleaning is a great challenge due to insufficient visible-light power conversion. Here we report a mass production approach to synthesize black titania by aluminium reduction. The obtained sample possesses a unique crystalline core-amorphous shell structure (TiO 2 @TiO 2Àx ). The black titania absorbs $65% of the total solar energy by improving visible and infrared absorption, superior to the recently reported ones ($30%) and pristine TiO 2 ($5%). The unique core-shell structure (TiO 2 @TiO 2Àx ) and high absorption boost the photocatalytic water cleaning and water splitting.The black titania is also an excellent photoelectrochemical electrode exhibiting a high solar-to-hydrogen efficiency (1.7%). A large photothermic effect may enable black titania "capture" solar energy for solar thermal collectors. The Al-reduced amorphous shell is proved to be an excellent candidate to absorb more solar light and receive more efficient photocatalysis.

Modification of rutile titanium dioxide (TiO2) for hydrogen generation and water cleaning is a grand challenge due to the chemical inertness of rutile, while such inertness is a desired merit for its stability in photoelectrochemical applications. Herein, we report an innovative two-step method to prepare a core-shell nanostructured S-doped rutile TiO2 (R'-TiO2-S). This modified black rutile TiO2 sample exhibits remarkably enhanced absorption in visible and near-infrared regions and efficient charge separation and transport. As a result, the unique sulfide surface (TiO(2-x):S) boosts the photocatalytic water cleaning and water splitting with a steady solar hydrogen production rate of 0.258 mmol h(-1) g(-1). The black titania is also an excellent photoelectrochemical electrode exhibiting a high solar-to-hydrogen conversion efficiency of 1.67%. The sulfided surface shell is proved to be an effective strategy for enhancing solar light absorption and photoelectric conversion.

A novel architecture of 3D graphene growth on porous Al2O3 ceramics is proposed for thermal management using ambient pressure chemical vapor deposition. The formation mechanism of graphene is attributed to the carbothermic reduction occurring at the Al2O3 surface to initialize the nucleation and growth of graphene. The graphene films are coated on insulating anodic aluminum oxide (AAO) templates and porous Al2O3 ceramic substrates. The graphene coated AAO possesses one‐dimensional isolated graphene tubes, which can act as the media for directional thermal transport. The graphene/Al2O3 composite (G‐Al2O3) contains an interconnected macroporous graphene framework with an extremely low sheet electrical resistance down to 0.11 Ω sq−1 and thermal conductivity with 8.28 W m−1 K−1. The G‐Al2O3 provides enormous conductive pathways for electronic and heat transfer, suitable for application as heat sinks. Such a porous composite is also attractive as a highly thermally conductive reservoir to hold phase change materials (stearic acid) for thermal energy storage. This work displays the great potential of CVD direct growth of graphene on dielectric porous substrates for thermal conduction and electronic applications.

The simultaneous control of the tacticity and molecular weight of poly(N-vinylpyrrolidone) during radical polymerization is reported for the first time. For molecular weight control, xanthates of (O-ethylxanthylmethyl)benzene and [1-(O-ethylxanthyl)ethyl]benzene were used as RAFT/MADIX chain transfer agents (CTAs) for the radical polymerization of N-vinylpyrrolidone (NVP). Both led to a controlled/living radical polymerization, and the latter showed higher chain transfer ability under the optimal conditions; the molecular weight distribution was 1.36 when the molecular weight was up to 26 700. The polymerization was studied between 20 and 120 °C and at various concentrations of CTA. All the polymerizations showed an induction period and rate retardation dependent on both the concentration of CTA and temperature. For tacticity control, the polymerization was carried out in fluoroalcohols via a conventional radical process without CTAs to give syndiotactic polymers. The polymer tacticity was dependent on the amount of the fluoroalcohol, and a more acidic and bulkier fluoroalcohol led to a higher syndiotacticity. Especially with (CF3)3COH, the r dyad increased to 62.6% from 53.5% for the atactic poly(NVP) obtained in the usual solvents. The 1H NMR analysis of the mixture of NVP and the fluoroalcohols indicated that a 1:1 hydrogen-bonding complex was formed, suggesting that the complex was responsible for the tacticity control of the polymer. When the CTA was used in the fluoroalcohols, the living and syndiospecific polymerization proceeded to enable the simultaneous control of the molecular weight and the tacticity.

Nanocapsule derived from hyperbranched polymer bears a number of active functional groups in the core; such a structure feature renders it possible to meticulously engineer the core of the nanocapsule and thus provides a unique opportunity to evaluate the structure-property relationship. Here the amino protons of HPEI (M n ) 10 000 Da) are 15%, 30%, 60%, and 86% alkylated with 2-dodecyloxymethyloxirane, leading to core-shell structured amphiphilic macromolecules (CAMs) with such different shell density as HP(EI-OH 0.15 C12 0.15 ) (3a), HP(EI-OH 0.30 C12 0.30 ) (3b), HP(EI-OH 0.60 C12 0.60 ) (3c), and HP(EI-OH 0.86 C12 0.86 ) (3d), respectively. The cores of 3a-3d are further chemically modified by complete alkylation of the residual amino protons with propylene oxide, leading to HP(EI-OH 1 C12 0.15 ) (4a), HP(EI-OH 1 C12 0.30 ) (4b), HP(EI-OH 1 C12 0.60 ) (4c), and HP(EI-OH 1 C12 0.86 ) (4d), respectively. Nanocapsule with thick shell is also obtained by alkylation of HPEI with epoxy polystyrene (M n ) 1800), leading to HPEI with 15% (HP(EI-OH 0.15 PS 0.15 ), 7a), 30% (HP(EI-OH 0.30 PS 0.30 ), 7b), and 60% (HP(EI-OH 0.60 PS 0.60 ), 7c) of the amino protons being alkylated. Water-soluble, anionic dyes can be encapsulated by these CAMs. It is found that 7a-7c exist as unimolecular inverted micelles in the tested range while 3a-3d and 4a-4d exist as aggregates in chloroform, indicating that a thick shell is crucial to the nature of unimolecular micelle. It is also found that the guest releasing ability is dependent on the nature of the functional groups in the core but independent of the shell density; thus, encapsulation of methyl orange by 3a-3c is reversible, while that by 4a-4c is irreversible. Congo red can be encapsulated by the aggregate of 3a-3d or 4a-4d, but excessive Congo reds cause precipitation of the aggregate. Finally, it is noticed that the molecule recognition property is also dependent on the nature of the functional groups in the core but independent of the shell density and shell thickness; as a result, a CAM with a designed core can highly selectively encapsulate a guest from a mixture.

Controlled radical polymerization of N‐vinylcaprolactam (NVCL) via reversible addition‐fragmentation chain transfer (RAFT) polymerization or macromolecular design via the interchange of xanthate (MADIX) was described, employing 2‐diphenylthiocarbamoylsulfanyl‐2‐methyl‐propionic acid (CTA1), ((O‐ethylxanthyl)methyl)benzene (CTA2) and (1‐(O‐ethylxanthyl)ethyl)benzene (CTA3) as chain transfer agents (CTA). It was found that all the CTAs led to controlled radical polymerization of NVCL, with the molecular weight increased along with the conversion of monomer and a relatively narrow molecular weight distribution could be obtained, as determined with matrix‐assisted laser desorption and ionization time‐of‐flight (MALDI‐TOF) and gel permeation chromatography (GPC), the polydispersity indices, as determined by MALDI‐TOF, were typically on the order of 1.24, but the polymerization did not proceed in a strictly living manner. The chain transfer ability of these CTAs was in the following order: CTA1 ≈ CTA2 < CTA3. MALTI‐TOF measurement showed that the major population of polymer retained the chain‐end functional group, but minor population deactivated by radical coupling. In preparation of the block copolymer of NVCL and vinyl acetate (VAc) by sequential polymerization, the sequence of monomer addition was important. Using VAc as the first monomer could lead to a block copolymer presenting a unimodal GPC trace and a narrow PDI index, and if NVCL was used as the first monomer, the polymerization was less well controlled. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3756–3765, 2008

A novel architecture of graphene paper is proposed to consist of "1D metallic nanowires/defect-free graphene sheets". Highly conductive and flexible papers of 1D silver nanowires (Ag NWs) and chemical vapor deposition (CVD) graphene sheets as an example were fabricated by a simple filtration method. CVD graphene paper possesses much higher electrical conductivity of 1097 S/cm, compared with other reported carbon-related papers (graphene, carbon nanotube, etc.). With the addition of Ag NWs to form Ag NWs/graphene paper, the electrical conductivity is further improved up to 3189 S/cm, even higher than ∼2000 S/cm of bulk graphite. Ag NWs/graphene papers have very good flexibility with the only <5% loss of electrical conductivity over 500 times mechanical bending. Highly conductive composite papers have potential in high-performance, flexible energy conversion and storage devices.