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Sunlight‐Driven Hydrogen Peroxide Production from Water and Molecular Oxygen by Metal‐Free Photocatalysts
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Dr. Yasuhiro Shiraishi Shunsuke Kanazawa Yusuke Kofuji Hirokatsu Sakamoto Dr. Satoshi Ichikawa Dr. Shunsuke Tanaka Prof. Takayuki Hirai 《Angewandte Chemie (International ed. in English)》2014,53(49):13454-13459
Design of green, safe, and sustainable process for the synthesis of hydrogen peroxide (H2O2) is a very important subject. Early reported processes, however, require hydrogen (H2) and palladium‐based catalysts. Herein we propose a photocatalytic process for H2O2 synthesis driven by metal‐free catalysts with earth‐abundant water and molecular oxygen (O2) as resources under sunlight irradiation (λ>400 nm). We use graphitic carbon nitride (g‐C3N4) containing electron‐deficient aromatic diimide units as catalysts. Incorporating the diimide units positively shifts the valence‐band potential of the catalysts, while maintaining sufficient conduction‐band potential for O2 reduction. Visible light irradiation of the catalysts in pure water with O2 successfully produces H2O2 by oxidation of water by the photoformed valence‐band holes and selective two‐electron reduction of O2 by the conduction band electrons. 相似文献
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Kazuya Takemoto Yoshiki Sakuma Shinichi Hirose Tatsuya Usuki Naoki Yokoyama Toshiyuki Miyazawa Motomu Takatsu Yasuhiko Arakawa 《Physica E: Low-dimensional Systems and Nanostructures》2005,26(1-4):185
We present an optical spectroscopy and photon correlation measurement at telecommunication wavelengths performed on single InAs/InP quantum dots. Two main approaches brought high optical quality: an application of a ‘double-cap’ growth method to metalorganic chemical vapor deposition, and fabrication of a small mesa structure using low-damage wet chemical etching. Sharp and discrete exciton transition lines have been observed on the single quantum dots, which widely cover the spectral range of 1.3–1.55 μm. Using a pulsed excitation source and gated single-photon detection modules, we observed a photon antibunching behavior for an isolated exciton emission line, indicating nonclassical light emission near the wavelength of 1.3 μm. 相似文献
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Karina R. Vega‐Villa Connie M. Remsberg Yusuke Ohgami Jaime A. Yáñez Jody K. Takemoto Preston K. Andrews Neal M. Davies 《Biomedical chromatography : BMC》2009,23(6):638-646
A stereospecific method of analysis of racemic taxifolin (+/?3,5,7,3′,4′‐pentahydroxyflavanone) in biological fluids is necessary to study pharmacokinetics and disposition in fruit and herbs. A simple high‐performance liquid chromatographic method was developed for the determination of all four taxifolin enantiomers. Separation was achieved on a Chiralcel® OJ‐RH column with UV detection at 288 nm. The standard curves in serum were linear over a range of 0.5–100.0 µg/mL for each enantiomer. The mean extraction efficiency was >88.0%. Precision of the assay was <15% (CV), and was within 12% at the limit of quantitation (0.5 µg/mL). The bias of the assay was <15%, and was within 6% at the limit of quantitation. The assay was successfully applied to stereospecific disposition of taxifolin enantiomers in rats and to the quantification of taxifolin enantiomers in tu fu ling (Rhizoma smilacis glabrae) and apple (Malus × domestica). Copyright © 2009 John Wiley & Sons, Ltd. 相似文献