Prolonged Hot Electron Dynamics in Plasmonic‐Metal/Semiconductor Heterostructures with Implications for Solar Photocatalysis

• DOI: 10.1002/ange.201404259
• Publication Date: 2014-06-11T12:38:24Z
• Authors: Joseph S. DuChene; Brendan C. Sweeny; Aaron C. Johnston...; Dong Su; Eric A. Stach; Wei David Wei
• Keywords: Visible spectrum; Plasmonic Nanoparticles

Abstract Ideal solar‐to‐fuel photocatalysts must effectively harvest sunlight to generate significant quantities of long‐lived charge carriers necessary for chemical reactions. Here we demonstrate the merits augmenting traditional photoelectrochemical cells with plasmonic nanoparticles satisfy these daunting photocatalytic requirements. Electrochemical techniques were employed elucidate mechanics plasmon‐mediated electron transfer within Au/TiO 2 heterostructures under visible‐light ( λ >515 nm) irradiation in solution. Significantly, discovered that transferred electrons displayed excited‐state lifetimes two orders magnitude longer than those photogenerated directly TiO via UV excitation. These further enable visible‐light‐driven H evolution from water, heralding a new paradigm solar energy conversion.