In the present paper, we combine absorption and Raman scattering measurements to characterize agg... more In the present paper, we combine absorption and Raman scattering measurements to characterize aggregated TSPP in homogeneous aqueous solution. We deduce that aggregation evolves through the formation of TSPP diacid and that the diacid is the repeating unit in the aggregate. We ...
International Journal of High Speed Electronics and Systems, 2008
The sol-gel method has been employed in the fabrication of mesoporous composite films consisting ... more The sol-gel method has been employed in the fabrication of mesoporous composite films consisting of a nonionic surfactant, Pluronic P123, as the organic component, and silica as the inorganic component. The hybrid nature of these films resulted in their having an internal structure consisting of nanometer size self-assembled organic mesostructures surrounded by a silica framework. These films served as the host matrix for the laser dye coumarin 481 (C481) and an energy transfer complex formed between C481 and J-aggregated meso-tetra(4-sulfonatophenyl)porphyrin (TSPP). Upon exposure to methanol vapor, a rapid and reversible decrease in fluorescence intensity occurs for films containing C481 alone as well as containing both C481 and TSPP. Steady-state and time-resolved spectroscopic studies suggest that the decrease in fluorescence intensity is primarily due to an excited state interaction between methanol and C481; while, additionally, morphological changes within the film appear to ...
We present a facile and efficient photobromination technique for the covalent sidewall functional... more We present a facile and efficient photobromination technique for the covalent sidewall functionalization of SWNT using N-bromosuccinamide as the bromine source.
ABSTRACT This study analyzes the synthesis of carbon-supported core–shell structured Cu@Pd cataly... more ABSTRACT This study analyzes the synthesis of carbon-supported core–shell structured Cu@Pd catalysts (Cu@Pd/C) through a galvanic replacement reaction to be utilized in the electrocatalytic oxidation of formic acid. The strategy used in this study explores the relationship among lattice strain, electronic structure, and catalytic performance. X-ray diffraction and X-ray photoelectron spectroscopy indicate that the inclusion of Cu in the nanocatalyst increases lattice strain and results in a downshift of the d-band of palladium. Electrochemical tests show that Cu@Pd/C catalysts exhibit weaker adsorption strength for CO with increased Cu content, which can be attributed to the downshift of the electronic d-band. For the synthesized materials, the Cu@Pd/C catalyst with a Cu:Pd atomic ratio of 27:73 is found to have the highest activity for formic acid oxidation. A peaklike plot between activity and atomic composition is acquired and reveals the relationship among lattice strain, electronic structure, and catalytic performance.
In the present paper, we combine absorption and Raman scattering measurements to characterize agg... more In the present paper, we combine absorption and Raman scattering measurements to characterize aggregated TSPP in homogeneous aqueous solution. We deduce that aggregation evolves through the formation of TSPP diacid and that the diacid is the repeating unit in the aggregate. We ...
International Journal of High Speed Electronics and Systems, 2008
The sol-gel method has been employed in the fabrication of mesoporous composite films consisting ... more The sol-gel method has been employed in the fabrication of mesoporous composite films consisting of a nonionic surfactant, Pluronic P123, as the organic component, and silica as the inorganic component. The hybrid nature of these films resulted in their having an internal structure consisting of nanometer size self-assembled organic mesostructures surrounded by a silica framework. These films served as the host matrix for the laser dye coumarin 481 (C481) and an energy transfer complex formed between C481 and J-aggregated meso-tetra(4-sulfonatophenyl)porphyrin (TSPP). Upon exposure to methanol vapor, a rapid and reversible decrease in fluorescence intensity occurs for films containing C481 alone as well as containing both C481 and TSPP. Steady-state and time-resolved spectroscopic studies suggest that the decrease in fluorescence intensity is primarily due to an excited state interaction between methanol and C481; while, additionally, morphological changes within the film appear to ...
We present a facile and efficient photobromination technique for the covalent sidewall functional... more We present a facile and efficient photobromination technique for the covalent sidewall functionalization of SWNT using N-bromosuccinamide as the bromine source.
ABSTRACT This study analyzes the synthesis of carbon-supported core–shell structured Cu@Pd cataly... more ABSTRACT This study analyzes the synthesis of carbon-supported core–shell structured Cu@Pd catalysts (Cu@Pd/C) through a galvanic replacement reaction to be utilized in the electrocatalytic oxidation of formic acid. The strategy used in this study explores the relationship among lattice strain, electronic structure, and catalytic performance. X-ray diffraction and X-ray photoelectron spectroscopy indicate that the inclusion of Cu in the nanocatalyst increases lattice strain and results in a downshift of the d-band of palladium. Electrochemical tests show that Cu@Pd/C catalysts exhibit weaker adsorption strength for CO with increased Cu content, which can be attributed to the downshift of the electronic d-band. For the synthesized materials, the Cu@Pd/C catalyst with a Cu:Pd atomic ratio of 27:73 is found to have the highest activity for formic acid oxidation. A peaklike plot between activity and atomic composition is acquired and reveals the relationship among lattice strain, electronic structure, and catalytic performance.
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