Time-resolved visible and infrared absorption difference spectroscopy data at both 298 and 77 K were obtained using cyanobacterial menB (-) mutant photosystem I particles with several non-native quinones incorporated into the A1 binding site. Data was obtained for photosystem I particles with phylloquinone (2-methyl-3-phytyl-1,4-naphthoquinone), 2-bromo-1,4-naphthoquinone, 2-chloro-1,4-naphthoq...

A series of organic sensitizers based on different configurations such as D-π-A, D-[π]n-A, D-π-[A]n, [D]n-π-A, D-π-A-π-D, D-π-[A]n-π-D and D-[π-A]n-π-D (where n = 1-4) are designed using theoretical methods. The effects of repeating π-linker, donor-acceptor moieties and the substitution of additional donor-acceptor moieties on the optoelectronic properties have been addressed. Our results show ...

The ichthyotoxin of Prymnesium parvum is inactivated by visible (400 to 510 mmu) as well as by ultraviolet light (255 mmu). The changes in the absorption spectrum of purified (pigment-free) ichthyotoxin during this process indicate that different mechanisms may be involved in the inactivation by visible or ultraviolet light. Photoinactivation is not affected by the presence of cells, cell pigme...

Erbium co-doped TiO2 /Ag catalysts are synthesized by using a simple, one-step solvothermal method and characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Raman analysis, X-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy. The catalysts exhibit anatase crystal structures with increased visible light absorption co...

Semiconductor compounds are widely used for photocatalytic hydrogen production applications, where photogenerated electron-hole pairs are exploited to induce catalysis. Recently, powders of a metallic oxide (Sr1-xNbO3, 0.03<x<0.20) were reported to show competitive photocatalytic efficiencies under visible light, which was attributed to interband absorption. This discovery expanded the range of...

In order to utilize visible light in photocatalytic reactions, nitrogen atoms were doped in commercially available photocatalytic TiO2 powders by using an organic compound such as urea and guanidine. Analysis by X-ray photoelectron spectroscopy (XPS) indicated that N atoms were incorporated into two different sites of the bulk phase of TiO2. A significant shift of the absorption edge to a lower...

A silver-acrylate nanocomposite was prepared using a novel one-pot strategy involving eosin dye as visible sensitizer and an amine derivative as radicals source. The mechanism highlighted by steady state photolysis and time resolved absorption spectroscopy lies on the initial formation of a strong ion pair complex between eosin and Ag + . Upon visible irradiation, the excited triplet state of t...

Optical glasses are optimized to provide excellent transmittance throughout the total visible range from 400 to 800 nm. Usually the transmittance range spreads also into the near UV and IR regions. As a general trend lowest refractive index glasses show high transmittance far down to short wavelengths in the UV. Going to higher index glasses the UV absorption edge moves closer to the visible ra...

To resolve the biggest problem in visible-to-UV photon upconversion based on sensitized triplet-triplet annihilation-the quenching of upconverted fluorescence by sensitizers-we discovered a superior sensitizer with less UV absorption intensity that enables highly efficient, low-power (0.78 mW cm(-2)) visible-to-UV upconversion.