Gold Nanoparticles Located at the Interface of Anatase/Rutile TiO₂ Particles as Active Plasmonic Photocatalysts for Aerobic Oxidation

Abstract

Visible-light irradiation (λ > 450 nm) of gold nanoparticles loaded on a mixture of anatase/rutile TiO(2) particles (Degussa, P25) promotes efficient aerobic oxidation at room temperature. The photocatalytic activity critically depends on the catalyst architecture: Au particles with <5 nm diameter located at the interface of anatase/rutile TiO(2) particles behave as the active sites for reaction. This photocatalysis is promoted via plasmon activation of the Au particles by visible light followed by consecutive electron transfer in the Au/rutile/anatase contact site. The activated Au particles transfer their conduction electrons to rutile and then to adjacent anatase TiO(2). This catalyzes the oxidation of substrates by the positively charged Au particles along with reduction of O(2) by the conduction band electrons on the surface of anatase TiO(2). This plasmonic photocatalysis is successfully promoted by sunlight exposure and enables efficient and selective aerobic oxidation of alcohols at ambient temperature.

Solar-Powered Plasmon-Enhanced Heterogeneous Catalysis

“…Oxidation performed according to traditional catalysis, as well as oxidation on semiconductor photocatalysts such as TiO 2 , usually occurs under harsh conditions (e.g., high temperature and pressure) or delivers strong oxidation power [106,109]. However, the generation of plas- [109].…”

Elucidating the real-time Ag nanoparticle growth on α-Ag2WO4during electron beam irradiation: experimental evidence and theoretical insights

“…2,10,12,16,[30][31][32] Specifically, plasmonic noble metal nanocrystals have recently been found to enhance a number of chemical reactions due to localized surface plasmon resonances. [33][34][35][36][37][38][39][40][41][42][43][44][45] However, the nature of the mechanism of the plasmonic driven chemistry in the presence of hot electrons or charged species and the concurrent photoluminescence properties over plasmonic particles are not well understood. 33,37,46,47 This investigation's motivation essentially arises from the discovery of an unwanted real-time in situ nucleation and growth of Ag filaments on a-Ag 2 WO 4 crystals which was driven by an accelerated electron beam from an electronic microscope under high vacuum.…”

Synthesis and Characterization of Novel Plasmonic Ag/AgX-CNTs (X = Cl, Br, I) Nanocomposite Photocatalysts and Synergetic Degradation of Organic Pollutant under Visible Light

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