Laser flash photolysis study of the photochemical formation of colloidal Ag nanoparticles in the presence of benzophenone

Kometani, Noritsugu; Doi, Hidenori; Asami, Kōji; Yonezawa, Yoshiro

doi:10.1039/b205829d

Cited by 55 publications

(37 citation statements)

References 22 publications

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“…It is seen that the kinetic model thus represents the concentration dependences of the MFEs very well, both at short and long times. Whereas the quenching rate constant k 2 differs by less than 20 % from the one found in homogeneous solution, [6] k 1 is an order of magnitude lower than the values reported for hydrogen abstraction from SDS by triplet benzophenone, [25][26][27] which were obtained by RYDMR (reaction-yield-detected magnetic resonance) measurements. The most likely reason is a different electronic configuration of the triplet, np* in the case of benzophenone and pp* in the case of xanthone.…”

Section: Resultscontrasting

confidence: 53%

Quenching Mechanisms and Diffusional Pathways in Micellar Systems Unravelled by Time‐Resolved Magnetic‐Field Effects

Goez

Henbest

Windham

et al. 2009

Chemistry A European J

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Magnetic-field effects (MFEs) are used to investigate the photoreaction of xanthone (A) and DABCO (D) in anionic (SDS) or cationic (DTAC) micelles at high pH (DABCO = 1,4-diazabicyclo[2.2.2]octane, SDS = sodium dodecyl sulfate, DTAC = dodecyl trimethyl ammonium chloride). From MFE experiments with nanosecond time resolution, the radical anion A(.)(-) can be observed without any interference from the much more strongly absorbing triplet (3)A*, the different quenching processes can be separated and their rates can be measured. Triplet (3)A* is quenched dynamically both by the SDS micelle (k(1) = 5.0x10(5) s(-1)) and by DABCO approaching from the aqueous phase (k(2) = 2.0x10(9) M(-1) s(-1)). Static quenching by solubilised DABCO (association constant with the SDS micelles, 1.5 M(-1)) also participates at high DABCO concentrations, but is chemically nonproductive and does not lead to MFE generation. The MFEs stemming from the radical ion pairs A(.)(-) D(.)(+) are about 40 times larger in the anionic micelles than in the cationic ones despite a higher yield of free radicals in the latter case. This can be rationalised by different diffusional dynamics: Because of the location of their precursors, A(.)(-) and D(.)(+) are formed at opposite sides of the micelle boundary. Subsequently, the negatively charged Stern layer of the SDS micelle traps the radical cation, which then undergoes surface diffusion, so both the recombination probability and the spin mixing are high; in contrast, the positive surface charge of the DTAC micelle forces the radical cation into the bulk of the solution, thus efficiently blocking a recombination.

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Section: Resultscontrasting

confidence: 53%

Quenching Mechanisms and Diffusional Pathways in Micellar Systems Unravelled by Time‐Resolved Magnetic‐Field Effects

Goez

Henbest

Windham

et al. 2009

Chemistry A European J

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“…On the other hand, benzophenone is a typical hydrogen-abstraction type activator. Benzophenone ketyl radical (BPK) formed by the hydrogen abstraction reaction of the benzophenone triplet from ethanol is able to reduce Ag + ions [27].…”

Section: Resultsmentioning

confidence: 99%

Synthesis of ruthenium particles by photoreduction in polymer solutions

Harada

Takahashi

2008

Journal of Colloid and Interface Science

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“…Photochemical reduction is an important approach and has been applied to the synthesis of metallic nanoparticles [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53]. However, its use in the synthesis of bimetallic nanoparticles is not well established.…”

Section: Synthesis Of Plasmonic Bimetallic Alloy Nanoparticlesmentioning

confidence: 99%

Recent Advances in the Synthesis of Plasmonic Bimetallic Nanoparticles

2009

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The importance of plasmonic nanoparticles in sensor development, imaging, photodiagnostics, and optoelectronics has resulted in a strong interest toward the development of straightforward synthetic methods for their preparation. In this article, we review some of the most significant advances that have been made in the synthesis of plasmonic bimetallic nanoparticles. Approaches to control morphology, with an emphasis on reactions that produce uniform particles with well-defined sizes and shapes and in high yields, are described. In addition, several characterization techniques that have been employed to elucidate the morphology of the particles are illustrated.

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Laser flash photolysis study of the photochemical formation of colloidal Ag nanoparticles in the presence of benzophenone

Cited by 55 publications

References 22 publications

Quenching Mechanisms and Diffusional Pathways in Micellar Systems Unravelled by Time‐Resolved Magnetic‐Field Effects

Quenching Mechanisms and Diffusional Pathways in Micellar Systems Unravelled by Time‐Resolved Magnetic‐Field Effects

Synthesis of ruthenium particles by photoreduction in polymer solutions

Recent Advances in the Synthesis of Plasmonic Bimetallic Nanoparticles

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