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.

/pdf/visible-light-photocatalysis-in-nitrogen-doped-titanium-np6nklr9gh.pdf

Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides

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

The surface science of titanium dioxide

We report a high-efficiency photoinduced phase transition in a spin-crossover complex [FeL(CN)2]∙H2O (where L is a N3O2 Schiff-base macrocyclic ligand) A single-shot laser pulse (8ns duration) is applied to induce the phase transformation, exhibiting molecular-structural, chromatic, and magnetic changes inside a thermal hysteresis loop (216K) The condensation of long lifetime photoexcited high-spin sites accounts for the cooperative photoexcitation process

Photoinduced phase transition in an iron(II) spin-crossover complex with a N3O2 macrocyclic ligand

A scanning tunneling microscope under potentiostatic control in visible light illumination was used in aqueous solutions to investigate an in situ dynamical light‐induced morphological transformation of n‐MoS2, a representative layer‐type semiconductor electrode. In a KCl solution, light‐induced corrosion originated from ‘‘layer‐island’’ structures, island edges, and depressions, all of which served as active reaction sites. The electrode surface was then morphologically transformed by photoelectrochemical processes into a stable van der Waals’ surface. Additionally, the effect of I− ions on the suppression of photocorrosion of n‐MoS2 was investigated.

Photoelectrochemical in situ observation of n‐MoS2 in aqueous solutions using a scanning tunneling microscope

Photoelectrochemical polymerization of pyrrole occurs at irradiated areas of semiconducting electrodes in aqueous solution of pyrrole. Organic conducting polypyrrole patterns were formed on semiconductors by area-selective irradiation of the semiconductor electrodes. The deposition rate was 0.5–0.7 μm per 100 mC. The conductivity of the deposited polypyrrole film was ca. l S cm−1

/pdf/generation-of-organic-conducting-patterns-on-semiconductors-2t6cui27mk.pdf

Akira Fujishima

Papers

Photoinduced phase transition in an iron(II) spin-crossover complex with a N3O2 macrocyclic ligand

Photoelectrochemical in situ observation of n‐MoS2 in aqueous solutions using a scanning tunneling microscope

Generation of organic conducting patterns on semiconductors by photoelectrochemical polymerization of pyrrole

Unusually long-lived light-induced metastable state in a thermochromic copper(II) complex.

A new method of pH control by use of a polypyrrole coated electrode