In situ generation of catalyst-coated cadmium sulfide particles in polymerized and unpolymerized surfactant vesicles and their utilization for efficient visible-light-induced hydrogen production

Quenching of CdS Fluorescence with Benzyl Alcohol via Transmembrane Diffusion in Dihexadecyl Phosphate Vesicles

“…In agreement with the earlier observations, 7c-e the typical absorption and emission spectra of the CdS particles incorporated into DHP vesicles unambiguously indicated the quantum-sized characteristics (Figure ) with an average diameter of about 5 nm. 1a, Although CdS particles were formed on both sides of the DHP vesicles, previous studies pointed out that only those CdS particles were emissive which were located at the interior vesicle surfaces. 7e,8a The emission maximum at 514 nm indicates a predominantly excitonic fluorescence . Similar fluorescence properties were observed with quantum-sized CdS particles prepared in montmorillonite clay and in Langmuir−Blodgett films, probably as a consequence of the tight packing in these systems.…”

“…Since earlier observations indicated a significant aging effect, 7e,8a most of the quenching experiments were carried out 30 min after the in situ formation of CdS (i.e., 30 min after the introduction of H 2 S). Fluorescence measurements carried out on the same system a week after the preparation of CdS confirmed that aging dramatically diminishes (by about 10 times) the quenching efficiency of benzyl alcohol.…”

“…In studies of CdS-particle-mediated transmembrane photoelectron transfer in dihexadecyl phosphate (DHP) vesicles benzyl alcohol was used as an efficient sacrificial electron donor because it is capable of diffusing through the DHP membrane without destroying it . Quantum yield measurements indicated that in the case of CdS particles located on the inner surface of the vesicles the rate-determining step of the photoinduced electron transfer was the membrane-limited diffusion of benzyl alcohol. 7d,e Since CdS particles prepared inside the DHP vesicles display photoluminescence which can be quenched with benzyl alcohol, this phenomenon offers a possibility to obtain quantitative information on this transmembrane diffusion. Since this electron donor is a local anaesthetic compound, investigation of its diffusion may also contribute to the characterization of the anaesthetic−membrane interactions of physiological significance. , …”

Photovoltaic effect in symmetrical cells of a liquid crystal porphyrin

“…Increased crystallinity has often improved the photoelectronic properties of organic thin films,12JS~Z2~23 although some counterexamples have been reported. These cells showed photovoltaic characteristics comparable to some of the better organic solar cells3-' even though they were completely symmetrical and relatively thick (1)(2)(3)(4)(5)(6). These cells consisted of an LCP capillary-filled between two pieces of indium-tin oxide (ITO) coated glass separated by polymer spacers (see Figure 1).…”

Nanocrystal Quantum Dots: From Discovery to Modern Development

“…The study of semiconductor particles in liquid colloids does not share the long history of stained-glass development. In the 1970s and 1980s, chemists in the United States and Europe, including Bard, Fendler, Gratzel, and Henglein − among others, began to explore semiconductor colloids, mostly for solar energy applications. While these particles were generally too large to show confinement, Henglein did observe optical size effects and modeled them semiclassically.…”