Activation of oxygen on gold and silver nanoparticles assisted by surface plasmon resonances.
Surface plasmon resonances (SPRs) have been found to promote chemical reactions. In most oxidative chemical reactions oxygen molecules participate and understanding of the activation mechanism of oxygen molecules is highly important. For this purpose, we applied surface-enhanced Raman spectroscopy (SERS) to find out the mechanism of SPR-assisted activation of oxygen, by using p-aminothiophenol (PATP), which undergoes a SPR-assisted selective oxidation, as a probe molecule. In this way, SPR has the dual function of activating the chemical reaction and enhancing the Raman signal of surface species. Both experiments and DFT calculations reveal that oxygen molecules were activated by accepting an electron from a metal nanoparticle under the excitation of SPR to form a strongly adsorbed oxygen molecule anion. The anion was then transformed to Au or Ag oxides or hydroxides on the surface to oxidize the surface species, which was also supported by the heating effect of the SPR. This work points to a promising new era of SPR-assisted catalytic reactions.
State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, MOE laboratory of Spectrochemical Analysis and Instrumentation, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China) http://bren.xmu.edu.cn.
Yi-Fan
YF
Huang
Meng
M
Zhang
Liu-Bin
LB
Zhao
Jia-Min
JM
Feng
De-Yin
DY
Wu
Bin
B
Ren
Zhong-Qun
ZQ
Tian
nanoparticles; oxidation; oxygen; surface plasmon resonances; surface-enhanced Raman spectroscopy