Hot hole mediated catalytic oxidative scission of alkenes using hybrid plasmonic nanoparticles Swathi Swaminathan * , Jitendra K. Bera and Manabendra Chandra Department of Chemistry, Indian Institute of Technology, India Visible light-mediated charge carrier (hot electrons and hot holes) generation from plasmonic nanoparticles has shown promise in driving chemical reactions. In particular, the development of new materials called hybrid plasmonic nanostructures is a topic of rapidly growing interest in photocatalysis, which promotes this quest for effective charge carrier generation. 1 The use of charge carriers in catalysis has facilitated the modification of reaction landscapes while opening up reaction paths that remain inaccessible through thermal processes; for example, the hot electrons promotion of reactions such as H₂ dissociation, 2 or ethylene epoxidation. 3 Despite numerous examples characterizing hot electron-driven processes, utilizing hot holes generated from metal nanoparticles has received scant attention. 4,5 In this work, we utilized core-shell Au@Ag nano cuboctahedrons as a plasmon photocatalyst to catalyze the oxidative scission of alkenes to aldehydes. We show the influence of incorporating a dissimilar metal into monometallic plasmonic nanoparticles on the optical and electronic properties of the resultant hybrid nanostructure. The hot holes captured effectively from the hybrid plasmonic nanoparticles enabled the complete oxidation of olefins. We observed enhanced reaction rates and conversion for styrene oxidation to benzaldehyde with Au@Ag NPs, excited their LSPR. Our work demonstrates the simultaneous harvesting of multiple hot holes, thus expanding the possibilities of hot hole utilization in photocatalysis. Detailed mechanistic studies attribute the enhanced catalytic activity of the hybrid plasmonic nanostructures to the electronic perturbation at the Au-Ag interface, aided by utilizing multiple-generated hot holes. Further, under visible light excitation, the core-shell hybrid plasmonic system reduced the activation barrier for catalysis. We also compared the catalytic activity of hybrid plasmonic system Au@Ag cuboctahedrons with their monometallic counterparts, i.e., Au nanoctahedrons and Ag nanocubes, structures which possess sharp features for charge carrier accumulation. The experimental framework outlined in this work can be used to develop hybrid plasmonic systems for challenging reactions that demand multiple charge carriers harvesting. References 1. S. Ezendam, M. Herran, L. Nan, C. Gruber, Y. Kang, F. Gröbmeyer, R. Lin, J. Gargiulo, A. Sousa-Castillo and E. Cortés, ACS Energy Lett. , 2022, 778–815. 2. S. Mukherjee, F. Libisch, N. Large, O. Neumann, L. V. Brown, J. Cheng, J. B. Lassiter, E. A. Carter, P. Nordlander and N. J. Halas, Nano Lett. , 2013, 13 , 240–247. 3. P. Christopher, H. Xin, A. Marimuthu and S. Linic, Nat. Mater. , 2012, 11 , 1044–1050. 4. J. S. DuChene, G. Tagliabue, A. J. Welch, W.-H. Cheng and H. A. Atwater, Nano Lett. , 2018, 18 , 2545–2550. 5. W. Guo, A. C. Johnston-Peck, Y. Zhang, Y. Hu, J. Huang and W. D. Wei, J. Am. Chem. Soc. , 2020, 142 , 10921–10925.
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