Ultrafast Dynamics of Plasmon-Exciton Interaction of Ag Nanowire- Graphene Hybrids for Surface Catalytic Reactions

Abstract

Using the ultrafast pump-probe transient absorption spectroscopy, the femtosecond-resolved plasmon-exciton interaction of graphene-Ag nanowire hybrids is experimentally investigated, in the VIS-NIR region. The plasmonic lifetime of Ag nanowire is about 150 ± 7 femtosecond (fs). For a single layer of graphene, the fast dynamic process at 275 ± 77 fs is due to the excitation of graphene excitons, and the slow process at 1.4 ± 0.3 picosecond (ps) is due to the plasmonic hot electron interaction with phonons of graphene. For the graphene-Ag nanowire hybrids, the time scale of the plasmon-induced hot electron transferring to graphene is 534 ± 108 fs, and the metal plasmon enhanced graphene plasmon is about 3.2 ± 0.8 ps in the VIS region. The graphene-Ag nanowire hybrids can be used for plasmon-driven chemical reactions. This graphene-mediated surface-enhanced Raman scattering substrate significantly increases the probability and efficiency of surface catalytic reactions co-driven by graphene-Ag nanowire hybridization, in comparison with reactions individually driven by monolayer graphene or single Ag nanowire. This implies that the graphene-Ag nanowire hybrids can not only lead to a significant accumulation of high-density hot electrons, but also significantly increase the plasmon-to-electron conversion efficiency, due to strong plasmon-exciton coupling.

Hot‐Electron‐Mediated Photochemical Reactions: Principles, Recent Advances, and Challenges

“…[66] Recently, graphene-plasmonic nanostructure (Ag nanowire and bowtie nanoantenna arrays) hybrid platforms have been utilized for surface catalytic reactions. [67,68,88] Owing to the strong plasmon-exciton coupling, the Ag/graphene hybrid platform increased the plasmon-toelectron conversion efficiency and induced a significant accumulation of high-density hot electrons, thereby enhancing the efficiency of surface catalytic reactions in comparison with those individually assisted by single Ag nanowires or graphene monolayers. [67] Furthermore, the plasmon-driven surface-catalyzed reaction could be controlled by altering the electron transfer as a function of the number of graphene layers.…”

“…[67,68,88] Owing to the strong plasmon-exciton coupling, the Ag/graphene hybrid platform increased the plasmon-toelectron conversion efficiency and induced a significant accumulation of high-density hot electrons, thereby enhancing the efficiency of surface catalytic reactions in comparison with those individually assisted by single Ag nanowires or graphene monolayers. [67] Furthermore, the plasmon-driven surface-catalyzed reaction could be controlled by altering the electron transfer as a function of the number of graphene layers. [68] As mentioned above, DMAB can be produced from pNTP through plasmon-driven surface-catalyzed chemical reactions.…”

“…Since 2010, various experimental and theoretical results have supported the production of DMAB from pATP by plasmon-driven surface-catalyzed chemical reactions. [61][62][63][64][65][66][67][68][69][70][71][72] Adv. Optical Mater.…”

Exciton-plasmon coupling interactions: from principle to applications

“…Ding et al [141] constructed a hybrid system of silver nanowire and graphene, which was used to promote chemical reactions by extending the electronic lifetime. The advantages of this hybrid device are shown in Figure 8 through ultrafast pump-probe transient absorption (UPPTRA) spectroscopy and surface reactions on this hybrid nanostructure.…”

Pt-Based Nanostructures for Observing Genuine SERS Spectra of p-Aminothiophenol (PATP) Molecules

“…Among various nanostructures, the hollow nanostructure has attracted significant attention owing to its high surface area [6], low density, and potential applications in a series of technologies, such as catalysis [7], optical detection [8][9][10][11], and photothermal therapy [12]. Therefore, it is of interest to explore hollow-structured nanomaterials in the hope of disclosing their important physical properties.…”