Probing the Catalytic Activity of Reduced Graphene Oxide Decorated with Au Nanoparticles Triggered by Visible Light
item.page.type
Artigo
Date
2015
item.page.ispartof
Chemistry - A European Journal
item.page.citationsscopus
22
Authors
Wang J.
Trindade F.J.
De Aquino C.B.
Pieretti J.C.
Domingues S.H.
Ando R.A.
Camargo P.H.C.
Trindade F.J.
De Aquino C.B.
Pieretti J.C.
Domingues S.H.
Ando R.A.
Camargo P.H.C.
publication.page.advisor
Journal Title
Journal ISSN
Volume Title
publication.page.board
publication.page.program
Abstract
© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.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<inf>4</inf><sup>-</sup><inf>(aq)</inf> 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<inf>2</inf> through the transfer of SPR-excited hot electrons to O<inf>2</inf> 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<inf>2</inf> 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<inf>2</inf> charge-transfer process.
Description
Keywords
item.page.scopussubject
Au nanoparticle , Charge transfer process , Mediated activities , Model reactions , P-aminothiophenol , Reduced graphene oxides , Reduced graphene oxides (RGO) , Situ reduction