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Probing the Catalytic Activity of Reduced Graphene Oxide Decorated with Au Nanoparticles Triggered by Visible Light
Author(s) -
Wang Jiale,
Trindade Fabiane J.,
de Aquino Caroline B.,
Pieretti Joana C.,
Domingues Sergio H.,
Ando Romulo A.,
Camargo Pedro H. C.
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201500677
Subject(s) - graphene , ascorbic acid , electron transfer , oxide , catalysis , photochemistry , materials science , surface plasmon resonance , nanoparticle , excited state , adsorption , molecule , photocatalysis , redox , nanotechnology , chemical engineering , chemistry , atomic physics , organic chemistry , physics , food science , engineering , metallurgy
Hybrid materials in which reduced graphene oxide (rGO) is decorated with Au nanoparticles (rGO–Au NPs) were obtained by the in situ reduction of GO and AuCl 4 − (aq) by ascorbic acid. On laser excitation, rGO could be oxidized as a result of the surface plasmon resonance (SPR) excitation in the Au NPs, which generates activated O 2 through the transfer of SPR‐excited hot electrons to O 2 molecules adsorbed from air. The SPR‐mediated catalytic oxidation of p ‐aminothiophenol (PATP) to p , p ′‐dimercaptoazobenzene (DMAB) was then employed as a model reaction to probe the effect of rGO as a support for Au NPs on their SPR‐mediated catalytic activities. The increased conversion of PATP to DMAB relative to individual Au NPs indicated that charge‐transfer processes from rGO to Au took place and contributed to improved SPR‐mediated activity. Since the transfer of electrons from Au to adsorbed O 2 molecules is the crucial step for PATP oxidation, in addition to the SPR‐excited hot electrons of Au NPs, the transfer of electrons from rGO to Au contributed to increasing the electron density of Au above the Fermi level and thus the Au‐to‐O 2 charge‐transfer process.