Photocatalysis of Au25-modified TiO2 under visible and near infrared light

Visible light-driven photocatalysis of Au₂₅-modified TiO₂ was investigated. It induces oxidation of phenol derivates and ferrocyanide and reduction of Ag⁺, Cu²⁺ and dissolved oxygen. Thermodynamically uphill reactions such as oxidation of phenol accompanied by reduction of Cu²⁺ are also driven. The photocatalysis, which is based on the excitation of Au₂₅, is observed even under 860 nm light.     

Amino-functionalized SBA-15 type mesoporous silica having nanostructured hexagonal platelet morphology

Amino-functionalized SBA-15 type mesoporous silicas having unique hexagonal platelet morphologies with short channels (100-300 nm) running parallel to the thickness of the nanostructured hexagonal platelet type morphologies have been directly synthesized by co-condensation of aminopropyltriethoxysilane (APTES) and sodium metasilicate as a silica source in the presence of Pluronic P123 triblock copolymer as a structure directing agent.     

Formation of highly ordered mesoporous titania films consisting of crystalline nanopillars with inverse mesospace by structural transformation

Highly ordered mesoporous titania films consisting of crystalline nanopillars with open-spaced, perpendicular, and continuous porosity have been prepared via structural transformation from a 3D hexagonal mesostructure during the thermal treatment. The mechanism of the structural transformation is explained by the crystallization of the titania framework and the large contraction of the initial 3D hexagonal mesostructured film upon calcination. This structural transformation provides a new approach to generate mesoporous thin-film materials with unique structures.     

Mechanisms of photocatalytic remote oxidation

The mechanisms of photocatalytic remote oxidation have been elucidated. Hydrogen peroxide, generated on a photocatalyst (TiO2, Pt-TiO2, or Ag-TiO2), is transported in air and then photocleaved into hydroxyl radicals by UV light in the vicinity of a substrate, and the hydroxyl radicals attack the substrate.     

Sobolev embeddings for Riesz potential spaces of variable exponents near 1 and Sobolev's exponent

Our aim in this paper is to deal with Sobolev embeddings for Riesz potentials of order α for functions f satisfying the Orlicz type condition

     

Crystal-like periodic mesoporous organosilica bearing pyridine units within the framework

Periodic mesoporous organosilica with densely packed pyridine units within the framework and crystal-like molecular-scale periodicity was synthesized. The framework pyridines were chemically active and fully accessible for protonation and Cu(2+) adsorption.     

Remote energy storage in Ni(OH)2 with TiO2 photocatalyst

Oxidative energy generated by UV-irradiated TiO2 photocatalyst was stored in Ni(OH)2 that was 12.5-50 microm apart from the TiO2. It is likely that active oxygen species generated on TiO2 diffused into the gas phase and oxidized Ni(OH)2. Loading the TiO2 with Pt accelerated the remote energy storage by an order of magnitude. It was revealed that the stored energy could be taken out and used chemically or electrochemically. The oxidized Ni(OH)2 was reduced by gaseous formaldehyde, formate, ethanol and H2O2.     

Visible light-induced photocatalysts with reductive energy storage abilities

Reductive energy from visible light-responsive Au–TiO₂ photocatalyst, which is based on plasmon resonance absorption of Au nanoparticles, can be stored in WO₃ as a reductive energy storage material. About 60% of the charge stored in WO₃ is consumed on the WO₃ and the other 40% is on the Au–TiO₂ by reduction of ambient O₂. Electrochemically pretreated MoO₃ can also be used as an energy storage material.     

Synthesis of optically active,unnatural α-substituted glutamic acid derivatives by a chiral calcium-catalyzed 1,4-addition reaction

The first catalytic asymmetric 1,4-addition reactions of azlactones with acrylic esters have been developed. A chiral coordinative calcium catalyst was found to be effective for these reactions, and the desired 1,4-adducts were obtained in good yields and enantioselectivities. The product was converted to the corresponding α-alkylated glutamic acid by acid hydrolysis.     

Electroactive supramolecular self-assembled fibers comprised of doped tetrathiafulvalene-based gelators

New electroactive supramolecular fibers have been formed by self-assembly of the derivatives of tetrathiafulvalene (TTF) in liquid crystals. These derivatives are designed and prepared by introducing the TTF moiety to the scaffold derived from amino acids such as L-isoleucine whose derivatives function as organogelators. These TTF-based gelators form stable fibrous aggregates in liquid crystals. These fibers are the first example of hydrogen-bonded one-dimensional aggregates having electroactive moieties whose electrical conductivities were measured after doping. Their electronic states have also been characterized by spectroscopic methods. Unidirectionally aligned fibers are formed in the oriented liquid crystal solvents on the rubbed polyimide surface for further functionalization of the fibers.