Hot carrier multiplication in plasmonic photocatalysis

Linan Zhou; Minhan Lou; Junwei Lucas Bao; Chao Zhang; Jun G Liu; John Mark P Martirez; Shu Tian; Lin Yuan; Dayne F Swearer; Hossein Robatjazi; Emily A Carter; Peter Nordlander; Naomi J Halas

doi:10.1073/pnas.2022109118

Hot carrier multiplication in plasmonic photocatalysis

Proc Natl Acad Sci U S A. 2021 May 18;118(20):e2022109118. doi: 10.1073/pnas.2022109118.

Authors

Linan Zhou^{1

2}, Minhan Lou², Junwei Lucas Bao^{3

4}, Chao Zhang², Jun G Liu⁵, John Mark P Martirez⁶, Shu Tian¹, Lin Yuan¹, Dayne F Swearer¹, Hossein Robatjazi^{1

2}, Emily A Carter^{7

6

8}, Peter Nordlander^{9

5}, Naomi J Halas^{10

2

5}

Affiliations

¹ Department of Chemistry, Rice University, Houston, TX 77005.
² Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005.
³ Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544.
⁴ Department of Chemistry, Boston College, Chestnut Hill, MA 02467.
⁵ Department of Physics and Astronomy, Rice University, Houston, TX 77005.
⁶ Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095.
⁷ Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544; eac@ucla.edu nordland@rice.edu halas@rice.edu.
⁸ Office of the Chancellor, University of California, Los Angeles, CA 90095.
⁹ Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005; eac@ucla.edu nordland@rice.edu halas@rice.edu.
¹⁰ Department of Chemistry, Rice University, Houston, TX 77005; eac@ucla.edu nordland@rice.edu halas@rice.edu.

Abstract

Light-induced hot carriers derived from the surface plasmons of metal nanostructures have been shown to be highly promising agents for photocatalysis. While both nonthermal and thermalized hot carriers can potentially contribute to this process, their specific role in any given chemical reaction has generally not been identified. Here, we report the observation that the H₂-D₂ exchange reaction photocatalyzed by Cu nanoparticles is driven primarily by thermalized hot carriers. The external quantum yield shows an intriguing S-shaped intensity dependence and exceeds 100% for high light intensities, suggesting that hot carrier multiplication plays a role. A simplified model for the quantum yield of thermalized hot carriers reproduces the observed kinetic features of the reaction, validating our hypothesis of a thermalized hot carrier mechanism. A quantum mechanical study reveals that vibrational excitations of the surface Cu-H bond is the likely activation mechanism, further supporting the effectiveness of low-energy thermalized hot carriers in photocatalyzing this reaction.

Keywords: carrier multiplication; hot electrons; photocatalysis; photochemistry; plasmon.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.