Surface Plasmon Resonance (SPR) Electron and Energy Transfer in Noble Metal−Zinc Oxide Composite Nanocrystals

Abstract

Au-and Ag-ZnO composite nanocrystals having a dumbbell-like structure were successfully synthesized through the nucleation and decomposition of zinc hydroxide at the surface of pre-existing Au and Ag nanoparticles, respectively. The average size of the Au and Ag nanoparticles used was ∼4 nm and that of the ZnO nanocrystals was ∼10 nm. The composite nanocrystals show strong crystallinity of face-centered cubic and wurztite structures from Au or Ag and ZnO, respectively. The composite nanocrystals show enhanced UV light emission due not only to the surface electron transfer from the Au or Ag to the ZnO by the surface plasmon resonance (SPR) but also to the extension of the Fermi energy level to the ZnO. The Au-ZnO composite nanocrystals showed significantly suppressed visible light luminescence, while the Ag-ZnO did not show any apparent difference compared to the ZnO nanocrystals.

Enhanced photocatalytic activity in Ag-nanoparticle-dispersed BaTiO3 composite thin films: Role of charge transfer

“…The visiblerange emission around 424 nm, called nonradiative recombination, occurs possibly due to the recombination between e  in a defect level and h + in the VB. Similar behavior has been reported in noble metal/ZnO system [40]. The emission intensity of the Ag 25 /BTO increases compared to that of the monolithic BTO film, suggesting the occurrence of CT from Ag NPs to BTO (named CT SPR ) under visible light.…”

Dye-modified ZnO nanohybrids: optical properties of the potential solar cell nanocomposites

“…As Laali or Zobo molecule complexed with Zn 2? , the electron accumulates at the interface between the dye and ZnO, leading to the downward band bending of the ZnO side and thus to the easy electron transfer from Laali, in particular, to the ZnO side [26]. Figure 6 plausibly represent the band bending Fermi energy of the ZnO and electron transfer from Laali dye to the ZnO.…”

“…The reason for this is also due to the fact that, under this analogy, light scattering is stronger than absorption leading to efficient transfer of electron from Laali dye to ZnO as further provided in the literature [26] based on Rayleigh theory [27].…”

Sonophotocatalytic mineralization of Norflurazon in aqueous environment

“…Since the deferred recombination of electronic charges enhances the active radicals produced from the photocatalytic microenvironment. The loading of noble metal nanoparticles (Au, Ag and Pt) significantly increases the optical as well as catalytic properties of the resulting ZnO nanocatalysts (Subramanian et al, 2003;Lee et al, 2008;Wang et al, 2003).…”