Abstract Utilizing plasmon‐generated hot carriers to drive chemical reactions has emerged as a popular topic in solar photocatalysis. However, a complete description of the underlying mechanism of hot‐carrier transfer in photochemical processes remains elusive, particularly for those involving hot holes. Photoelectrochemistry enables to localize hot holes on photoanodes and hot electrons on photocathodes and thus offers an approach to separately explore the hole‐transfer dynamics and electron‐transfer dynamics. This review summarizes a comprehensive understanding of both hot‐hole and hot‐electron transfers from photoelectrochemical studies on plasmonic electrodes. Additionally, working principles and applications of spectroelectrochemistry are discussed for plasmonic materials. It is concluded that photoelectrochemistry provides a powerful toolbox to gain mechanistic insights into plasmonic photocatalysis.
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Mechanism for plasmon-generated solvated electrons
Solvated electrons are powerful reducing agents capable of driving some of the most energetically expensive reduction reactions. Their generation under mild and sustainable conditions remains challenging though. Using near-ultraviolet irradiation under low-intensity one-photon conditions coupled with electrochemical and optical detection, we show that the yield of solvated electrons in water is increased more than 10 times for nanoparticle-decorated electrodes compared to smooth silver electrodes. Based on the simulations of electric fields and hot carrier distributions, we determine that hot electrons generated by plasmons are injected into water to form solvated electrons. Both yield enhancement and hot carrier production spectrally follow the plasmonic near-field. The ability to enhance solvated electron yields in a controlled manner by tailoring nanoparticle plasmons opens up a promising strategy for exploiting solvated electrons in chemical reactions.
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- Award ID(s):
- 2124983
- PAR ID:
- 10448618
- Date Published:
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 120
- Issue:
- 3
- ISSN:
- 0027-8424
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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