ALTHOUGH the possibility of water photolysis has been investigated by many workers, a useful method has only now been developed. Because water is transparent to visible light it cannot be decomposed directly, but only by radiation with wavelengths shorter than 190 nm (ref. 1).

Electrochemical Photolysis of Water at a Semiconductor Electrode

Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

To use solar irradiation or interior lighting efficiently, we sought a photocatalyst with high reactivity under visible light. Films and powders of TiO 2- x N x have revealed an improvement over titanium dioxide (TiO 2 ) under visible light (wavelength 2 has proven to be indispensable for band-gap narrowing and photocatalytic activity, as assessed by first-principles calculations and x-ray photoemission spectroscopy.

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Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

The surface science of titanium dioxide

A photocatalyst element structure includes a photocatalyst element that includes a flat photocatalyst sheet and an undulating photocatalyst sheet overlapped on the flat photocatalyst sheet. The flat photocatalyst sheet and the undulating photocatalyst sheet include a porous titanium foil having a non-periodic spongy structure impregnated with anatase titanium dioxide particles. The photocatalyst element structure can include a plurality of the photocatalyst elements so that the flat photocatalyst sheet and the undulating photocatalyst sheet alternate.

Photocatalyst element structure, ultraviolet radiation air purification system, photocatalyst sheet, and method of manufacturing photocatalyst sheet

Anodically oxidized diamond electrodes have enabled direct oxidation of not only thiols but also disulfides such as oxidized glutathione. Coupled with LC separation after sample pretreatment, simultaneous determination of oxidized and reduced glutathione in rat whole blood was achieved at 1.50 V vs Ag/AgCl. The present method was comparable with enzymatic assay in real sample analysis.

Amperometric Detection of Oxidized and Reduced Glutathione at Anodically Pretreated Diamond Electrodes

Photoacoustic spectroscopy of the passive film on iron

We report a bidirectional reversible light-induced excited spin state trapping (LIESST) effect featuring an associated memorey effect in an Fe(II) spin-crossover complex [FeL(CN)2]·H2O (where L is a Schiff-base macrocyclic ligand). Depending on the illumination history, bidirectional LIESST processes have been successfully observed that are induced by irradiation with the same two wavelengths. A large zero-point energy difference, strong overlapping spectra of the high-spin and low-spin bands and image internal pressure could account for this photomagnetic phenomenon.

Photoinduced magnetic memory effect in an iron (II) spin-crossover complex

The photoelectrochemical behavior of p-type boron phosphide (p-BP) in acidic solution was investigated. The p-BP photocathode was stable in sulfuric acid solution under irradiation, and the band gap deduced from the photocurrent action spectrum in acidic solution was 2.0 eV. The gas evolved from p-BP photocathode was hydrogen which was obtained with a current efficiency of ca. 100%. The photocurrent was markedly increased by suitable ruthenium treatment of the BP. A photoelectrochemical cell (PEC), Pt(H2)/0.5 M H2SO4(1 M=1 mol dm−3)/ /0.5 M H2SO4/p-BP, was shown to have an open-circuit photovoltage of 0.45 V and a fill factor of 0.25.

Akira Fujishima

Papers

Photocatalyst element structure, ultraviolet radiation air purification system, photocatalyst sheet, and method of manufacturing photocatalyst sheet

Amperometric Detection of Oxidized and Reduced Glutathione at Anodically Pretreated Diamond Electrodes

Photoacoustic spectroscopy of the passive film on iron

Photoinduced magnetic memory effect in an iron (II) spin-crossover complex

Photoelectrochemical Behavior of p-Type Boron Phosphide Photoelectrode in Acidic Solution