Ultraviolet photolysis of HOCl: REMPI measurement of the relative population of chlorine atom (P-2) spin-orbit states

The nascent chlorine atom (P-2) relative spin-orbit state population resulting from UV photolysis of HOCl has been measured by resonance-enhanced multiphoton ionization (REMPI) in single laser experiments. The ratio of (0.30 +/- 0.07) for Cl*:Cl has been obtained, indicating a stronger preference for production of ground-state Cl(P-2(3/2)) than expected from statistical weights. Also, the Cl+ arrival-time spectra show that most of the energy available in the photolysis is converted into kinetic energy of the photofragments

Ag/Pd core-shell nanoparticles by a successive method: Pulsed laser ablation of Ag in water and reduction reaction of PdCl2

In this study Ag/Pd nanoparticles (NPs) have been fabricated by a successive method; first, colloids of Ag nanoparticles (NPs) have been prepared in water by pulsed laser ablation in liquid (PLAL) method. Then PdCl2 solution (up to 0.2 g/l) were added to the as-prepared or aged colloidal Ag NPs. Characterizations were done using UV-vis spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmissions electron microscopy (TEM) techniques. Spectroscopy data showed that surface plasmon resonance (SPR) peaks of as-prepared Ag NPs at about lambda = 400nm were completely extinguished after addition of PdCl2 solution while this effect was not observed when aged Ag NPs are used. XRD and XPS results revealed that by addition of the PdCl2 solution into the as-prepared Ag NPs, metallic palladium, and silver chloride composition products are generated. TEM images revealed that as a result of this reaction, single and core-shell nanoparticles are obtained and their average sizes are 2.4 nm (Ag) and 3.2 nm (Ag/Pd). The calculated d-spacing values form XRD data with observations on high magnification TEM images were able to explain the chemical nature of different parts of Ag/Pd NPs. (C) 2013 Elsevier B.V. All rights reserved