Hybrid plasmonic tubular nanostructures: synthesis, optical and photoelectrocatalytic property

Abstract

Utilizing sustainable and clean solar energy in the visible-NIR range to drive chemical transformation has been a key resolution to solve the energy crisis. Recently, rational design of photocatalysts that conjugate plasmonic nanostructures with catalytic metal nanostructures has attracted particular research interests. This dissertation describes the design principles of plasmonic-catalytic hybrid tubular nanostructures and investigates their application in photoelectrocatalytic reactions.First, we introduced the mechanism of plasmon-mediated catalysis and current research of plasmonic photocatalysts. Specifically, managing the energy flow from the plasmonic entity to the catalytic entity is the crucial part for customizable design of photoelectrocatalysts. We also summarized the design principles of general electrocatalysts and synthesis of hollow nanostructures. Second, we reported a facile but highly reproducible synthetic strategy to fabricate catalytic Pt hollow nanotubes (NTs). Scalable fabrication of ultrathin Pt NTs can be achieved through simple mediation of the concentration of the surfactant employed in the reaction. Third, we reported a template-directed synthesis of PtAu NTs with tunable localized surface plasmon resonance (LSPR) bands in the visible-near infrared region (NIR). The geometric dependent LSPR band shift was systematically studied based off the spectra from both experiment and finite-difference time-domain (FDTD) simulations. It was found that the PtAu NTs exhibited the LSPR characters of both rodlike and hollow nanostructures. Finally, we investigated the photoelectrocatalytic performance of the PtAu NTs under visible-NIR light irradiation. The optimized photocatalytic activity of the PtAu NTs towards the electrooxidation of methanol was achieved by maximizing their LSPR absorption cross sections at longer wavelengths in the visible-NIR region. Meanwhile, combining the superior intrinsic electrocatalytic performance of PtAu NTs towards methanol oxidation, we expected the bimetallic PtAu tubular nanostructure could effectively convert visible light energy to drive the electrochemical transformation.