Nonstoichiometric rutile TiO2 photoelectrodes for improved photoelectrochemical water splitting.

A new type of nonstoichiometric rutile titanium dioxide (TiO2) film with around 15 at% oxygen vacancies homogeneously distributed throughout the bulk was prepared. The resultant films, when used as a photoelectrode, showed a photoelectrochemical water splitting activity 1.7 times that of stoichiometric TiO2 at a bias of 0.

Nitrogen-doped carbon monolith for alkaline supercapacitors and understanding nitrogen-induced redox transitions.

A nitrogen-doped porous carbon monolith was synthesized as a pseudo-capacitive electrode for use in alkaline supercapacitors. Ammonia-assisted carbonization was used to dope the surface with nitrogen heteroatoms in a way that replaced carbon atoms but kept the oxygen content constant. Ammonia treatment expanded the micropore size-distributions and increased the specific surface area from 383 m(2) g(-1) to 679 m(2) g(-1).

Photocatalytic water oxidation on F, N co-doped TiO2 with dominant exposed {001} facets under visible light.

Visible-light-responsive anatase TiO(2) platelets with dominant {001} facets were prepared via a facile nitridation reaction from a TiOF(2) precursor. The in situ co-doping of N and F in the anatase TiO(2) nanoparticles leads to drastically enhanced absorption and excellent water oxidation performance in the visible light region.

Yolk/shell nanoparticles: new platforms for nanoreactors, drug delivery and lithium-ion batteries.

Yolk/shell or 'rattle-typed' nanomaterials with nanoparticle cores inside hollow shells are interesting among the complex hollow nanostructures. Yolk/shell nanoparticles (YSNs) are promising functional nanomaterials for a variety of applications such as catalysis, delivery, lithium-ion batteries and biosensors due to their tailorability and functionality in both the cores and hollow shells. This feature article provides an overview of advances in this exciting area of YSNs, covering systematic synthesis approaches and key promising applications based on the literature and our own recent work.

Nitrogen doping in ion-exchangeable layered tantalate towards visible-light induced water oxidation.

An ion-exchangeable layered photocatalyst CsCa(2)Ta(3)O(10) was doped with nitrogen. The as-prepared photocatalyst (N-doped CsCa(2)Ta(3)O(10)) is stable and demonstrates high performance for catalyzing water oxidation under visible light irradiation.

Preparation of capacitor's electrode from sunflower seed shell.

Series of nanoporous carbons are prepared from sunflower seed shell (SSS) by two different strategies and used as electrode material for electrochemical double-layer capacitor (EDLC). The surface area and pore-structure of the nanoporous carbons are characterized intensively using N2 adsorption technique. The results show that the pore-structure of the carbons is closely related to activation temperature and dosage of KOH.

Effect of surface phosphorus functionalities of activated carbons containing oxygen and nitrogen on electrochemical capacitance.

Micro/mesoporous activated carbons containing oxygen and phosphorus heteroatoms were modified by incorporation of nitrogen using melamine and urea precursors. The surface chemistry was analyzed by the means of elemental analysis, XPS, and (31)P MAS NMR. The results indicate that upon the incorporation of nitrogen at high temperatures not only new species involving carbon/nitrogen/oxygen are formed but also the phosphorous environment is significantly altered.

Solving hierarchical helical mesostructures by electron tomography.

A direct method to determine the pitch and chirality of complicated hierarchical helical mesostructures is presented by using the state-of-the-art electron tomography technique.

Mesoporous Co3O4 and Au/Co3O4 catalysts for low-temperature oxidation of trace ethylene.

Low-temperature catalysts of mesoporous Co(3)O(4) and Au/Co(3)O(4) with high catalytic activities for the trace ethylene oxidation at 0 degrees C are reported in this paper. The catalysts were prepared by using the nanocasting method, and the mesostructure was replicated from three-dimensional (3D) cubic KIT-6 silicas. High resolution transmission electron microscopy (HRTEM) studies revealed that {110} facets were the exposed active surfaces in the mesoporous Co(3)O(4), whereas the Co(3)O(4) nanosheets prepared by the precipitation method exhibited the most exposed {112} facets.

Titanate-silica mesostructured nanocables: synthesis, structural analysis and biomedical applications.

1D hierarchical composite mesostructures of titanate and silica were synthesized via an interfacial surfactant templating approach. Such mesostructures have complex core-shell architectures consisting of single-crystalline H(2)Ti(3)O(7) nanobelts inside the ordered mesoporous SiO(2) shell, which are nontoxic and highly biocompatible. The overall diameter of as-prepared 1D hierarchical composite mesostructures is only approx.

Evolution of helical mesostructures.

An intriguing evolution from a simple internal helix to a hierarchical helical (HH) mesostructure with both internal and external helices or a complicated screwlike and concentric circular (CC) mesostructure is successfully observed. The complicated helical structures are determined by TEM studies and 3D electron tomography. We demonstrate a topological helix-coil transition between the internal and external helices to reveal the origin of the HH mesostructure and the relationship between the straight helical and HH rods.

Ti-Zr-O nanotube arrays with controlled morphology, crystal structure and optical properties.

A series of Ti-Zr-O nanotube arrays on Ti-Zr alloys with different ratios of Ti to Zr were prepared by a simple anodization process, and their morphologies, crystal structures and optical properties were investigated. It is found that the morphology, length, crystal structure and optical properties of Ti-Zr-O tubes can be well controlled by adjusting the ratio of Ti to Zr in Ti-Zr alloys. The tubes obtained evolved from circa (ca.

Enhanced photocatalytic hydrogen evolution by prolonging the lifetime of carriers in ZnO/CdS heterostructures.

Coupled ZnO/CdS heterostructures based on the Z-scheme mechanism are demonstrated to be highly active photocatalysts for H(2) evolution under simulated solar light irradiation due to the greatly prolonged lifetime of photoexcited carriers.

Fabrication of Graphene/Polyaniline Composite Paper via In Situ Anodic Electropolymerization for High-Performance Flexible Electrode.

Freestanding and flexible graphene/polyaniline composite paper was prepared by an in situ anodic electropolymerization of polyaniline film on graphene paper. This graphene-based composite paper electrode, consisting of graphene/polyaniline composite sheets as building blocks, shows a favorable tensile strength of 12.6 MPa and a stable large electrochemical capacitance (233 F g(-1) and 135 F cm(-3) for gravimetric and volumetric capacitances), which outperforms many other currently available carbon-based flexible electrodes and is hence particularly promising for flexible supercapacitors.

Hybrid nanocomposite colloidal crystals via in-situ synthesis of nanoparticles within polyelectrolyte shell.

Three-dimensional (3D) colloidal crystals with polyelectrolyte (PE)/nanoparticles (NPs) hybrid shells were fabricated by crystallization of PE multilayer-coated colloidal particles on quartz substrates followed by in-situ synthesis of NPs within the PE shell via ion-exchange and chemical reduction. Both metal (Ag) and semiconductor (CdS) NPs could be formed on the particle shell. It was also demonstrated that the position of the stop band of the colloidal crystal could be finely tuned by adjusting the shell composition.

Highly stable performance of supercapacitors from phosphorus-enriched carbons.

Phosphorus-rich microporous carbons (P-carbons) prepared by a simple H(3)PO(4) activation of three different carbon precursors exhibit enhanced supercapacitive performance in 1 M H(2)SO(4) when highly stable performance can be achieved at potentials larger than the theoretical decomposition potential of water. This ability of P-carbons greatly enhances the energy density of supercapacitors that are capable of delivering 16 Wh/kg compared to 5 Wh/kg for the commercial carbon. An intercept-free multiple linear regression model confirms the strongest influence of phosphorus on capacitance together with micropores 0.

Highly thermostable anatase titania-pillared clay for the photocatalytic degradation of airborne styrene.

Airborne styrene is a suspected human carcinogen, and traditional ways of mitigation include the use of adsorption technologies (activated carbon or zeolites) or thermal destruction. These methods presenttheir own shortcomings, i.e.

Novel boron nitride hollow nanoribbons.

Novel BN hollow nanoribbons (BNHNRs) were fabricated by a simple ZnS nanoribbon templating method. Such BNHNRs have a distinct structure and show unique optical properties, as demonstrated from Raman, Fourier transform infrared spectroscopy, UV-vis spectroscopy, and cathodoluminescence spectroscopy, when compared with other forms of BN nanostructures. With high crystallinity, the BNHNRs exhibit an extraordinary ultraviolet CL emission at 5.

Self-assembly and cathodoluminescence of microbelts from Cu-doped boron nitride nanotubes.

We report the self-assembly of microbelts from Cu-doped boron nitride nanotubes by chemical vapor deposition using Cu as a catalyst. The BN nanotubes with Cu-encapsulated flat tips have uniform outer diameters of approximately 240 nm, inner diameters of approximately 210 nm, and lengths of approximately 10 microm, and Cu is found to uniformly dope into the nanotubes. Most importantly, the nanotubes are self-assembled to form microbelts with 10 microm in width and tens of micrometers in length.

Molecular events in deliquescence and efflorescence phase transitions of sodium nitrate particles studied by Fourier transform infrared attenuated total reflection spectroscopy.

The NaNO(3) droplets with sizes of 1-5 microm generated from a nebulizer were deposited on a ZnSe substrate in a Fourier transform infrared attenuated total reflection (FTIR-ATR) chamber. After solidification of the droplets with dry N(2) gas passing through the chamber, the solid NaNO(3) particles were monitored by in situ FTIR-ATR spectra in cycles of deliquescence and efflorescence processes with varying relative humidities (RHs). With an increase in the RH, a dominant peak at approximately 3539 cm(-1), together with three relatively weak peaks at approximately 3400, approximately 3272, and approximately 3167 cm(-1), in the O-H stretching band of water was resolved by the high signal-to-noise ratio FTIR-ATR spectra.

Computational study of methyl derivatives of ammonia borane for hydrogen storage.

The structures and thermodynamic properties of methyl derivatives of ammonia-borane (BH3NH3, AB) have been studied with the frameworks of density functional theory and second-order Møller-Plesset perturbation theory. It is found that, with respect to pure, methyl ammonia-boranes show higher complexation energies and lower reaction enthalpies for the release of H2, together with a slight increment of the activation barrier. These results indicate that the methyl substitution can enhance the reversibility of the system and prevent the formation of BH3/NH3, but no enhancement of the release rate of H2 can be expected.

Amorphous TiO(2) nanotube arrays for low-temperature oxygen sensors.

Titania nanotube arrays (TNTA) were synthesized on a titanium substrate using anodic oxidation in an electrolyte containing ammonium fluoride and evaluated for low-temperature oxygen sensing. Their sensing properties were tested at different temperatures (50, 100, 150, 200, 250 and 300 °C) when exposed to various oxygen concentrations. The as-prepared TNTA are amorphous and exhibit much higher carrier concentration than that of annealed TNTA.

Mesoporous silica templated biolabels with releasable fluorophores for immunoassays.

A novel class of fluorescent immuno-biolabeling systems with extremely high F/P ratio (approximately 1000-6000) were prepared by combining the template method and layer-by-layer (LbL) technique. Labels were constructed by loading organic dye fluorescein diacetate (FDA) molecules onto hollow periodic mesoporous organosilica (H-PMO) particles followed by ployelectrolyte encapsulation and antibody attachment. The labeling systems were stimuli-responsive to the addition of concentrated NaOH with the loaded dye molecules being released and detected in a well-controlled manner.

Anatase TiO2 single crystals with a large percentage of reactive facets.

Owing to their scientific and technological importance, inorganic single crystals with highly reactive surfaces have long been studied. Unfortunately, surfaces with high reactivity usually diminish rapidly during the crystal growth process as a result of the minimization of surface energy. A typical example is titanium dioxide (TiO2), which has promising energy and environmental applications.