Water reduction and oxidation on Pt-Ru/Y2Ta2O5N2 catalyst under visible light irradiation

Y2Ta2O5N2 is presented as a novel photocatalyst with high activity for water splitting under visible-light irradiation in the presence of appropriate sacrificial reagents; the activity for reduction to H-2 is increased by the incorporation of Pt or Ru as a co-catalyst, with a significant increase in production efficiency when both Pt and Ru are present.

Photo-sensitized oxidation in natural water via .OH radicals

A method is presented for determining production and consumption rates of .OH radicals produced photochemically in natural surface waters. It is based on the determination of the kinetics by which the concentration of a specified trace compound decreases during irradiation. In samples from Lake Greifensee (Switzerland) low production rates for .OH limit its possible effects. In addition, fast consumptions by the natural dissolved organic solutes and by the bicarbonate protect organic micropollutants from oxidation by .OH. Neither direct nor indirect H2O2 photolysis was a significant source of .OH in the lakewater studied lacking iron, whereas nitrate photolysis could have been a source. Comparison with reaction kinetic formulations allows generalizations for other types of waters.

Rare-earth-metal mixed hydride/aryloxide complexes bearing mono(cyclopentadienyl) ligands. Synthesis, CO2 fixation, and catalysis on copolymerization of CO2 with cyclohexene oxide

Hydrogenolysis of mono(cyclopentadienyl)-ligated rare-earth-metal bis(alkyl) complexes Cp'Ln-(CH2SiMe3)2(THF) (Ln = Y (1a), Dy (1b), Lu (1c); Cp' = C5Me4SiMe3) with PhSiH3 afforded the mixed hydride/alkyl complexes [Cp'Ln(mu-H)(CH2SiMe3)(THF)](2) (Ln = Y (2a), Dy (2b), Lu (2c)). The overall structure of complexes 2a-c is a C-2-symmetric dimer containing a planar symmetric Ln(2)H(2) core at the center of the molecule. Deprotonation of ArOH (Ar = C6H2-Bu-t(2)-2,6-Me-4) by the metal alkyl group of 2a-c led to formation of the mixed hydride/aryloxide derivatives [Cp'Ln(mu-H)(OAr)](2) (Ln = Y (3a), Dy (3b), Lu (3c)), which adopt the dimeric structure through hydride bridges with trans-accommodated terminal aryloxide groups.

Controllable synthesis of VSB-5 micirospheres and microrods: Growth mechanism and selective hydrogenation catalysis

Nanoporous VSB-5 nickel phosphate molecular sieves with relatively well controllable sizes and morphology of microspheres assembled from nanorods were synthesized at 140 degrees C over a short time in the presence of hexamethylenetetramine (HMT) by a facile hydrothermal method. The pH value, reaction time, and ratio of HMT to NaHPO2-H2O crucially influence the morphology and quality of the final products.

Electrochemical characteristics of mediated laccase-catalysis and electrochemical detection of environmental pollutants

Laccase has been immobilized on the carbon nanotubes modified glassy carbon electrode surface by adsorption. As-prepared laccase retains good electrocatalytic activity to oxygen reduction by using 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) as the mediator. It can be used as a biosensor for the determination of catechol with broad linear range.

Macroporous Pt modified glassy carbon electrode: preparation and electrocatalytic activity for methanol oxidation

Three-dimensional (3D) macroporous Pt (MPPt) with highly open porous walls has been successfully synthesized using the hydrogen bubble dynamic template synthesis and galvanic replacement reaction. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electrochemical methods were adopted to characterize their structures and properties.

Platinum-coated gold nanoporous film surface: Electrodeposition and enhanced electrocatalytic activity for methanol oxidation

This report describes the preparation of Pt-nanoparticle-coated gold-nanoporous film (PGNF) on a gold substrate via a simple "green" approach. The gold electrode that has been anodized under a high potential of 5 V is reduced by freshly prepared ascorbic acid (AA) solution to obtain gold nanoporous film electrode. Then the Pt nanoparticle is grown on the electrode by cyclic voltammetry (CV).

Quantum dots-bienzyme hybrid system for the sensitive determination of glucose

In this paper, we attempt to develop a sensitive detection method for glucose with the combination of the unique optical property of quantum dots and the specificity of enzymatic reactions. With glucose and hydroquinone as substrates, benzoquinone that intensively quenches the photoluminescence of quantum dots can be produced via the catalysis of bienzyme (glucose oxidase and horseradish peroxidase) system. A relatively low detection limit of 1.0 x 10(-8) mol/L can be achieved. Two linear ranges from 1.0 x 10(-6) to 1.5 x 10(-4) M and from 1.5 x 10(-4) to 1.0 x 10(-3) M were obtained.

Direct Electrochemistry and Electrocatalysis of Hemoglobin in Lipid Film Incorporated with Room-Temperature Ionic Liquid

A facile phospholipid/room-temperature ionic liquid (RTIL) composite material based on dimyristoylphosphatidylcholine (DMPC) and 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF6) was exploited as a new matrix for immobilizing protein. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were adopted to characterize this composite film. Hemoglobin (Hb) was chosen as a model protein to investigate the composite system. UV-vis absorbance spectra showed that Hb still maintained its heme crevice integrity in this composite film.