Simultaneous Harvesting of Multiple Hot Holes via Visible‐Light Excitation of Plasmonic Gold Nanospheres for Selective Oxidative Bond Scission of Olefins to Carbonyls. (12th January 2023)

• Record Type: Journal Article
• Authors: Swaminathan, Swathi; Bera, Jitendra K.; Chandra, Manabendra
• Is Part Of: Angewandte Chemie. Volume 135:Number 7(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-12
• Subjects: Gold Nanoparticles -- Hot Charge Carriers -- Hot Holes -- Plasmon Catalysis -- Styrene Oxidation; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202215933
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Using visible photoexcitation of gold nanospheres we successfully demonstrate the simultaneous harvesting of plasmon‐induced multiple hot holes in the complete oxidative scission of the C=C bond in styrene at room temperature to selectively form benzaldehyde and formaldehyde, which is a reaction that requires activation of multiple substrates. Our results reveal that, while extraction of hot holes becomes efficient for interband excitation, harvesting of multiple hot holes from the excited Au nanospheres becomes prevalent only beyond a threshold light intensity. We show that the alkene oxidation proceeded via a sequence of two consecutive elementary steps; namely, a binding step and a cyclic oxometallate transition state as the rate‐determining step. This demonstration of plasmon‐excitation‐mediated harvesting of multiple hot holes without the use of an extra hole transport media opens exciting possibilities, notably for difficult catalytic transformations involving multielectron oxidation processes. Abstract : Harvesting of multiple hot holes has been demonstrated using Au nanospheres for the plasmonic photocatalytic oxidative scission of olefin to carbonyls through a step‐down process. Interband photoexcitation of Au nanospheres beyond a threshold intensity leads to a spurt in hot‐carrier generation, enabling multifold enhancement in substrate activation compared to a dark process.