Tetsu Tatsuma

Nanoporous TiO(2) films loaded with gold and silver nanoparticles exhibit negative potential changes and anodic currents in response to visible light irradiation, so that the films would potentially be applicable to inexpensive photovoltaic cells, photocatalysts and simple plasmon sensors.

TiO2 coatings are known to protect some metals, including type 304 stainless steel, from corrosion on the basis of its reductive energy generated under UV irradiation. A TiO2 coating is coupled with a WO3 coating as an electron pool, in which the reductive energy can be stored. A WO3 film on a type 304 stainless steel plate can be charged by a UV-irradiated TiO2 coating on the same plate, in a 3 wt % NaCl aqueous solution, pH 5. The charged WO3 coating can protect the stainless steel plate from

Recent development of nanoplasmonics has stimulated chemists to utilize plasmonic nanomaterials for efficient and distinctive photochemical applications, and physicists to boldly go inside the "wet" chemistry world. The discovery of plasmon-induced charge separation (PICS) has even accelerated these trends. On the other hand, some confusion is found in discussions about PICS. In this perspective, we focus on differences between PICS and some other phenomena such as co-catalysis effect and plasmo

Reductive energy generated at a TiO2 photocatalyst under UV light can be stored in WO3 by coupling them together, and the stored energy can be used after dark. However, the reduction of WO3 requires cation intercalation for charge neutralization. Thus, behavior of the TiO2−WO3 composite on an ITO electrode was examined in nonelectrolytic media. When the TiO2 and WO3 were close to each other (less than 1 mm), WO3 could be reduced even in pure water or humid air (relative humidity ≥25%), by irradi

Glutathione-protected Au25 as well as Aun (n = 15, 18, 22, 29, 33, 39) clusters adsorbed on TiO2 electrodes exhibit anodic photocurrents and negative shifts of photopotential in response to visible and/or near-infrared light (400 < λ < 900 nm) on the basis of HOMO−LUMO and similar transitions, indicating that the electrodes are applicable to the conversion of light to electricity (see figure).

In the multicolor photochromism of TiO2 nanoporous films loaded with photocatalytically deposited Ag nanoparticles, visible light-induced electron transfer from Ag to oxygen molecules plays an essential role. Here we examined the effect of TiO2 on the electron transfer. We found that not only photocatalytically deposited Ag, but also electrodeposited Ag and commercially available Ag nanoparticles in a nanoporous TiO2 film exhibit the multicolor photochromism. The electrodeposited Ag exhibits the

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnzyme monolayer- and bilayer-modified tin oxide electrodes for the determination of hydrogen peroxide and glucoseTetsu. Tatsuma, Yusuke. Okawa, and Tadashi. WatanabeCite this: Anal. Chem. 1989, 61, 21, 2352–2355Publication Date (Print):November 1, 1989Publication History Published online1 May 2002Published inissue 1 November 1989https://pubs.acs.org/doi/10.1021/ac00196a007https://doi.org/10.1021/ac00196a007research-articleACS PublicationsRequest reuse

The remote bleaching of a dye, methylene blue, by UV-irradiated TiO2 was studied in the gas phase. A TiO2-coated glass plate was faced to a glass plate coated with methylene blue, separated by a small gap (12.5 to 500 μm), and the TiO2 coating was irradiated with UV light from the back. As a result, methylene blue was bleached in the gas phase containing oxygen, although it was inhibited by ethanol vapor. The remote bleaching is not a simple reduction of methylene blue to its leuco form; methyle

An ITO electrode was coated with a nanoporous TiO2 film, and the film was loaded with Au nanoparticles with different diameters (15, 40 and 100 nm). The electrode exhibited plasmon-induced photocurrents in the presence of Fe(2+/3+) couple under visible light (lambda > 420 nm). The quantum efficiency increased with increasing particle size, whereas the maximum photocurrent density decreased.

The remote oxidation of organic materials via the gas phase was studied in detail. A TiO2-coated glass plate was faced to an organic film separated by a small gap (50 μm to 2.2 mm), and the TiO2 was irradiated with UV light. As a result, aromatic and aliphatic substances were oxygenated and decomposed to generate CO2 by active oxygen species that were generated at the TiO2 surface and transported in the gas phase. The amount of CO2 generated during the irradiation with 1 mol of photons was estim

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPeroxidase-incorporated polypyrrole membrane electrodesTetsu. Tatsuma, Masayuki. Gondaira, and Tadashi. WatanabeCite this: Anal. Chem. 1992, 64, 10, 1183–1187Publication Date (Print):May 15, 1992Publication History Published online1 May 2002Published inissue 15 May 1992https://doi.org/10.1021/ac00034a019RIGHTS & PERMISSIONSArticle Views260Altmetric-Citations114LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article dow

Super-hydrophobic and super-hydrophilic gold surfaces were prepared by modifying microstructured gold surfaces with thiols. The perfluorodecanethiol (PFDT)-modified rough gold surface was converted from super-hydrophobic (water contact angle = 150–160°) to super-hydrophilic (0–10°) by photocatalytic remote oxidation using a TiO2 film. During the remote oxidation, oxygen-containing groups were introduced to the thiol, and finally, even sulfur atoms were removed. Super-hydrophobic/super-hydrophili

Localized surface plasmon resonance (LSPR) sensors serve as sensitive analytical tools based on refractive index changes, which can be applied to affinity-based chemical sensing and biosensing. However, to select the monitoring wavelength, monodisperse Au or Ag nanoparticles must be synthesized. Here we developed LSPR sensors that operate at arbitrary wavelengths after preirradiation at the corresponding wavelength. Polydisperse plasmonic Ag nanospheroids or nanorods are photocatalytically depos