Article

Plasmon resonant enhancement of carbon monoxide catalysis.

Department of Materials Science, University of Southern California, Los Angeles, California 90089, USA.
Nano Letters (Impact Factor: 13.03). 03/2010; 10(4):1314-8. DOI: 10.1021/nl9041214
Source: PubMed

ABSTRACT Irradiating gold nanoparticles at their plasmon resonance frequency creates immense plasmonic charge and high temperatures, which can be used to drive catalytic reactions. By integrating strongly plasmonic nanoparticles with strongly catalytic metal oxides, significant enhancements in the catalytic activity can be achieved. Here, we study the plasmonically driven catalytic conversion of CO to CO(2) by irradiating Au nanoparticle/Fe(2)O(3) composites. The reaction rate of this composite greatly exceeds that of the Au nanoparticles or Fe(2)O(3) alone, indicating that this reaction is not driven solely by the thermal (plasmonic) heating of the gold nanoparticles but relies intimately on the interaction of these two materials. A comparison of the plasmonically driven catalytic reaction rate with that obtained under uniform heating shows an enhancement of at least 2 orders of magnitude.

0 Bookmarks
 · 
238 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Plasmonic excitation of Au nanoparticles attached to the surface of ZnO catalysts using low power 532 nm laser illumination leads to significant heating of the catalyst and the conversion of CO2 and H2 reactants to CH4 and CO products. Temperature-calibrated Raman spectra of ZnO phonons show that intensity-dependent plasmonic excitation can controllably heat Au-ZnO from 30 to ∼600 °C and simultaneously tune the CH4 : CO product ratio. The laser induced heating and resulting CH4 : CO product distribution agrees well with predictions from thermodynamic models and temperature-programmed reaction experiments indicating that the reaction is a thermally driven process resulting from the plasmonic heating of the Au-ZnO. The apparent quantum yield for CO2 conversion under continuous wave (cw) 532 nm laser illumination is 0.030%. The Au-ZnO catalysts are robust and remain active after repeated laser exposure and cycling. The light intensity required to initiate CO2 reduction is low (∼2.5 × 10(5) W m(-2)) and achievable with solar concentrators. Our results illustrate the viability of plasmonic heating approaches for CO2 utilization and other practical thermal catalytic applications.
    Nanoscale 06/2013; · 6.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Heterogeneous catalysis is of paramount importance in chemistry and energy applications. Catalysts that couple light energy into chemical reactions in a directed, orbital-specific manner would greatly reduce the energy input requirements of chemical transformations, revolutionizing catalysis-driven chemistry. Here we report the room temperature dissociation of H2 on gold nanoparticles using visible light. Surface plasmons excited in the Au nanoparticle decay into hot electrons with energies between the vacuum level and the work function of the metal. In this transient state, hot electrons can transfer into a Feshbach resonance of an H2 molecule adsorbed on the Au nanoparticle surface, triggering dissociation. We probe this process by detecting the formation of HD molecules from the dissociations of H2 and D2, and investigate the effect of Au nanoparticle size and wavelength of incident light on the rate of HD formation. This work opens a new pathway for controlling chemical reactions on metallic catalysts.
    Nano Letters 11/2012; · 13.03 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We experimentally demonstrate a planar metamaterial analogue of electromagnetically induced transparency at optical frequencies. The structure consists of an optically bright dipole antenna and an optically dark quadrupole antenna, which are cut-out structures in a thin gold film. A pronounced coupling-induced reflectance peak is observed within a broad resonance spectrum. A metamaterial sensor based on these coupling effects is experimentally demonstrated and yields a sensitivity of 588 nm/RIU and a figure of merit of 3.8.
    Nano Letters 09/2009; 10(4):1103-7. · 13.03 Impact Factor

Full-text

View
15 Downloads
Available from