The ultrafast transfer of plasmon-induced hot electrons is considered an effective kinetics process to enhance the photoconversion efficiencies of semiconductors through strong localized surface plasmon resonance (LSPR) of plasmonic nanostructures. Although this classical sensitization approach is widely used in noble-metal-semiconductor systems, it remains unclear in nonmetallic plasmonic heterostructures. Here, by combining ultrafast transient absorption spectroscopy with theoretical simulations, IR-driven transfer of plasmon-induced hot electron in a nonmetallic branched heterostructure is demonstrated, which is fabricated through solvothermal growth of plasmonic W O nanowires (as branches) onto TiO electrospun nanofibers (as backbones). The ultrafast transfer of hot electron from the W O branches to the TiO backbones occurs within a timeframe on the order of 200 fs with very large rate constants ranging from 3.8 × 10 to 5.5 × 10 s . Upon LSPR excitation by low-energy IR photons, the W O /TiO branched heterostructure exhibits obviously enhanced catalytic H generation from ammonia borane compared with that of W O nanowires. Further investigations by finely controlling experimental conditions unambiguously confirm that this plasmon-enhanced catalytic activity arises from the transfer of hot electron rather than from the photothermal effect.

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Because of their perfect geometrical symmetry, spherical metal nanoparticles have attracted much attention for various applications, including fundamental studies and construction of plasmonic devices. In this work, monodisperse silver nanospheres (Ag NSs) in aqueous solution were directly prepared by a continuous process of seed-mediated growth followed by oxidative etching. Silver nanocubes (Ag NCs) were synthesized by a seed-mediated growth method and subsequently were transformed to Ag NSs by simple injection of Cu to the freshly prepared Ag NCs solution. Not requiring any centrifugation steps at both growth and etching stages makes this procedure convenient and efficient. The etching process and morphology evolution of silver nanostructure were monitored by UV-vis spectromater, SEM, and XRD. Monodisperse Ag NSs with broadly tunable diameters (from 37 to 68 nm) have been successfully prepared. The optical property of Ag NSs has been studied and the experimental results show fairly good consistency with simulation results. Furthermore, these Ag NSs prepared by our approach could be constructed into ordered superlattice by self-assembly technique based on their high monodispersity and sphericity.

Plasmonic noble‐metal nanostructures have been introduced into semiconductor photocatalytsts to enhance the efficiency of solar‐to‐fuels conversion. However, most researches in this field focus on the utilization of a single resonance mode of plasmonic noble‐metal to sensitize the photo‐activity of semiconductor. Here, a novel UV‐vis‐NIR‐driven plasmonic photocatalyst is developed through selective assembly of the Pt and CdS nanostructures onto the Au nanorods (NRs) via a controllable multi‐step wet‐chemistry route. By combining finite element simulations with transient absorption (TA) results, it is demonstrated that the dual‐resonance modes of anisotropic Au NRs can induce a unique synergistic effect between the plasmonic resonance energy transfer (RET) and hot electron transfer (HET) processes within the Au‐Pt‐CdS NRs. As such, upon simulated sunlight irradiation, the photocatalytic activity of Au‐Pt‐CdS NRs for H2 generation is higher than that of the optimal Pt‐loaded CdS nanoparticles (NPs) by almost one order of magnitude.