Ultrafast and Efficient Transport of Hot Plasmonic Electrons by Graphene for Pt Free, Highly Efficient Visible-Light Responsive Photocatalyst

Dinesh Kumar, Ahreum Lee, Taegon Lee, Manho Lim, Dong Kwon Lim

Research output: Contribution to journalArticlepeer-review

120 Citations (Scopus)

Abstract

We report that reduced graphene-coated gold nanoparticles (r-GO-AuNPs) are excellent visible-light-responsive photocatalysts for the photoconversion of CO2 into formic acid (HCOOH). The wavelength-dependent quantum and chemical yields of HCOOH shows a significant contribution of plasmon-induced hot electrons for CO2 photoconversion. Furthermore, the presence and reduced state of the graphene layers are critical parameters for the efficient CO2 photoconversion because of the electron mobility of graphene. With an excellent selectivity toward HCOOH (>90%), the quantum yield of HCOOH using r-GO-AuNPs is 1.52%, superior to that of Pt-coated AuNPs (quantum yield: 1.14%). This indicates that r-GO is a viable alternative to platinum metal. The excellent colloidal stability and photocatalytic stability of r-GO-AuNPs enables CO2 photoconversion under more desirable reaction conditions. These results highlight the role of reduced graphene layers as highly efficient electron acceptors and transporters to facilitate the use of hot electrons for plasmonic photocatalysts. The femtosecond transient spectroscopic analysis also shows 8.7 times higher transport efficiency of hot plasmonic electrons in r-GO-AuNPs compared with AuNPs.

Original languageEnglish
Pages (from-to)1760-1767
Number of pages8
JournalNano Letters
Volume16
Issue number3
DOIs
Publication statusPublished - 2016 Mar 9

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation o f K o r e a (NRF-2 0 1 3 R 1 A 1 A1 0 6 1 3 8 7, NRF - 2014R1A2A2A01002456) and the KU-KIST research fund. The authors also acknowledge Dr. Youngsoo Kim''s helpful discussion for the kinetic study.

Publisher Copyright:
© 2016 American Chemical Society.

Keywords

  • CO photoconversion
  • Plasmonic nanoparticles
  • hot electron
  • photochemical reaction
  • visible light irradiation

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanical Engineering

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