Generation Of Chemical Species Research Articles

Synthesis and Properties of Au Hydride

AbstractThe generation of chemical species from gases, noble metals and light interacting with localized surface plasmons represents a new paradigm for achieving low energy sustainable reaction pathways. Here, we demonstrate that the dissociation reaction of H2 meditated by the decay of localized surface plasmons of gold nanoparticles leads to the generation of a new material as detected by a change in the optical properties of the gold nanostructures. The effective permittivity measured by in situ spectroscopic ellipsometry shows a blue‐shift of 0.02 eV in the surface plasmon resonance, demonstrating the plausible formation of a metastable gold hydride layer on the surface of nanoparticles following the dissociation of H2. The formation of this gold hydride through the interaction of gold with atomic H is supported by first‐principles simulations. These calculations do not indicate a significant charge transfer upon hydrogenation of the (111) surface but rather large Friedel charge oscillations within the gold layer. Moreover, our blue‐shift is produced by the formation of a hydride leading to changes in critical band gaps in the electronic structure. For a coverage of 11%, the calculated peak of the imaginary part of the ZZ‐component of the dielectric tensor undergoes a blue shift of 28 nm from a hydrogen free peak at 574 nm.

Volume Effects of Atmospheric-Pressure Plasma in Liquids

Generation of chemical species by atmospheric-pressure plasma treatment of aqueous liquids is a result of reactions at the plasma/gas–liquid interface and subsequent diffusion and convection processes into the liquid volume. Using color forming reactions, acidification as well as generation of nitrite is visualized in the water treated by a surface dielectric barrier discharge under atmospheric conditions in ambient air.

D123 大気圧アルゴンプラズマ流と水の干渉機構(プラズマ利用技術の進展II)

The interaction mechanism between an argon plasma flow at atmospheric pressure and water surface was studied. The generation and residual of reactive oxygen species (ROS) in purified water were focused in this study. Exposure of a water surface to the plasma flow at atmospheric pressure for 10 min generated ROS in purified water. The ROS concentration increased greater than 30,000 counts/10 s with 43% of the ROS still remaining after 30min in air, whereas exposure only to the plasma emission did not affect the level of ROS in purified water. The generation of chemical species which were transported to the water surface was also clarified. The ROS in the former water had a weak bacteriostatic effect.