Decomposition of methyl orange using C-60 fullerene adsorbed on silica gel as a photocatalyst via visible-light induced electron transfer

Visible-light induced electron transfer reactions of C60 fullerene adsorbed on silica gel (C60/SiO2 powder) to methyl orange in water have been studied. The C60/SiO2 powder was simply prepared by mixing a toluene solution of the C60 fullerene with silica gel followed by evaporating the toluene. Irradiation by visible light (>420 nm) of the methyl orange aqueous solution (25 μM) in the presence of the C60/SiO2 powder and ascorbic acid resulted in the decomposition of the methyl orange. These results showed that the degradation conversion reached 96% after a 25-min visible light irradiation. The reaction also occurred by the irradiation of sunlight. The reductive products of methyl orange, N,N-dimethyl-p-phenylenediamine and sulfanilic acid, were ascertained and monitored by liquid chromatography/mass spectrometry (LC/MS). The reaction did not occur in the dark and in the absence of C60/SiO2 or ascorbic acid. The possible mechanism of the reaction is discussed. Furthermore, the C60/SiO2 powder was applied to a continuous flow system for the photodecomposition of methyl orange. C60/SiO2 powder was packed in a glass tube. The methyl orange solution was pumped into the glass tube, and the tube was irradiated by visible light or sunlight. The continuous decomposition of methyl orange was achieved by this method.ArticleAPPLIED CATALYSIS B-ENVIRONMENTAL. 166:544-550 (2015)journal articl

Nanocomposite of silk fibroin nanofiber and montmorillonite: Fabrication and morphology

The purpose of our research is creating a new nanocomposite material. Generally silk fibroin (SF) is regarded as a promising base material for biomedical uses. The incorporation of montmorillonite (MMT) into SF fibers would improve physical properties of the SF fibers. We investigated a new method of combining electospun SF with MMT. Specifically, electrospun silk nanofibers were treated with methanol and dipped in a MMT suspension. We could obtain a nanosheet composite of silk nanofibers and MMT. Their ultrastructures were successfully visualized by high resolution transmission electron microscopy. This compound was comprised of individual silk nanofibers surrounded by thin layers of MMT, each with a thickness of about 1.2 nm. This structure was confirmed by elemental analysis. We also performed IR, NMR and X-ray diffraction analyses in conjunction with morphological data. Conclusively we obtained a new composite of silk nanofiber and MMT, which has never been reported. Using this unique nanocomposite biological tests of its application for a scaffold for tissue engineering are under way.ArticleINTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES. 57:124-128 (2013)journal articl

Structures and physiological functions of silica bodies in the epidermis of rice plants

We characterized silica structures in the epidermis of rice plant leaves and investigated their physiological functions from optical and mechanical viewpoints. By treating the distribution of silica bodies as a triangular lattice in the xy plane, and performing a theoretical optical analysis on this lattice, we discovered that a reduction in the photonic density of states may inhibit leaves of rice plant from being heated markedly higher than 20 degrees C. Ladderlike structures in the epidermis were mechanically investigated. These structures are conjectured to inhibit flat leaves from undergoing twisting torsions, which may assist the leaf to absorb sunlight more effectively for photosynthesis. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3232204]ArticleAPPLIED PHYSICS LETTERS. 95(12):123703 (2009)journal articl

Decomposition of methyl orange using C60 fullerene adsorbed on silica gel as a photocatalyst via visible-light induced electron transfer

Visible-light induced electron transfer reactions of C60 fullerene adsorbed on silica gel (C60/SiO2 powder) to methyl orange in water have been studied. The C60/SiO2 powder was simply prepared by mixing a toluene solution of the C60 fullerene with silica gel followed by evaporating the toluene. Irradiation by visible light (>420 nm) of the methyl orange aqueous solution (25 μM) in the presence of the C60/SiO2 powder and ascorbic acid resulted in the decomposition of the methyl orange. These results showed that the degradation conversion reached 96% after a 25-min visible light irradiation. The reaction also occurred by the irradiation of sunlight. The reductive products of methyl orange, N,N-dimethyl-p-phenylenediamine and sulfanilic acid, were ascertained and monitored by liquid chromatography/mass spectrometry (LC/MS). The reaction did not occur in the dark and in the absence of C60/SiO2 or ascorbic acid. The possible mechanism of the reaction is discussed. Furthermore, the C60/SiO2 powder was applied to a continuous flow system for the photodecomposition of methyl orange. C60/SiO2 powder was packed in a glass tube. The methyl orange solution was pumped into the glass tube, and the tube was irradiated by visible light or sunlight. The continuous decomposition of methyl orange was achieved by this method.ArticleAPPLIED CATALYSIS B-ENVIRONMENTAL. 166:544-550 (2015)journal articl