Catalysis Communications
Short communication
Enhanced photocatalytic properties of a novel
GO-Ag-C H Ag O nanocomposite
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a
a
a,b,
a
a
b,
Fenglin Liu , Xianjie Chen , Lihong Tian ⁎, Bing Liu , Qinghua Xia , Xiaobo Chen ⁎⁎
a
Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules,
Hubei University, Wuhan 430062, PR China
b
Department of Chemistry, University of Missouri — Kansas City, Kansas City, MO 64110, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
A novel graphene oxide-Ag-C H Ag O nanocomposite was prepared by a facile precipitation reaction with the
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Received 10 March 2015
Received in revised form 12 April 2015
Accepted 13 April 2015
aid of photo-reduction. The rich surface functional groups of graphene oxide (GO) interacted with silver cations,
provided the nucleation sites and induced the formation of C Ag nanoparticles on the GO surface uniform-
ly. The nanocomposite displayed an enhanced photocatalytic activity compared with pure C Ag and GO
under simulated sunlight, due to the reduced recombination of plasmon-induced electron–hole pairs on the
Ag nanoparticles by the GO. This study likely provides one possibility of exploiting stable Ag/silver (I) complex
photocatalysts in dealing with environmental contaminants.
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Available online 21 April 2015
Keywords:
Graphene oxide
Silver citrate
© 2015 Elsevier B.V. All rights reserved.
Plasmonic photocatalyst
Nanocomposite
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. Introduction
and enhancing the photocatalytic activity of the Ag/silver citrate nano-
structure under visible light irradiation. However, a thorny problem is
The photocatalytic oxidation technology utilizing solar energy has
caught increasing interests in dealing with various environmental pollut-
ants [1,2]. Some significant photocatalysts (e.g., TiO ) can only respond to
the ultraviolent (UV) light which only accounts for ca. 5% in sunlight.
Therefore, exploiting efficient sunlight-triggered photocatalysts has a
practical significance. Since Huang et al. reported an efficient and stable
Ag/AgCl plasmonic photocatalyst under visible light, some Ag/silver
that silver citrate tends to photo-decompose, inhibiting the application
of silver citrate in dealing with the environmental problems. Therefore,
it is important to prevent silver citrate from photodecomposing. Recently,
many approaches, such as forming hetero-photocatalysts [9] and
employing stabilizers [10], have been taken to improve the photostability
of silver-containing compounds. Graphene oxide (GO) has been proven
to be a promising candidate for enhancing the photocatalytic activity
and photostability of silver-containing compounds, due to its unique con-
jugated structure, electronic property and high surface area [11–15].
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(
I) compounds plasmonic photocatalysts, AgX (X = Cl, Br, I) and
Ag PO , have attracted considerable attention due to the strong surface
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plasmonic absorption of the Ag nanoparticles in visible light region and
their excellently photocatalytic properties. Previous studies demonstrated
that the AgX and Ag PO surfaces were terminated with X and PO
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groups of negative charges and those groups played an important role
in attracting the holes from the plasmon-induced Ag nanoparticles, pro-
moting the separation of electron–hole pairs and improving the activity
of plasmonic photocatalysts [3–7]. This provides a reference for designing
new Ag/silver (I) compounds plasmonic photocatalysts.
Here, we report a novel graphene oxide-Ag-C
Ag ) nanocomposite prepared by a facile precipitation reaction
with the aid of photo-reduction. GO was employed to stabilize the Ag/
Ag structure and prevent the citrate from photo-oxidation.
The photocatalytic activity was investigated on the degradation of Rho-
damine B (RhB) and methyl orange (MO) under simulated sunlight. The
active species and photocatalytic mechanism were also studied in
details.
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H Ag O (GO-Ag-
C
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O
−
3−
C
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O
Silver (I) citrate complex is an environment-friendly material, mainly
studied in the antibacterial field currently [8]. On silver citrate surface,
there are some amounts of carboxylate groups with negative charges.
Those groups are beneficial to attracting the holes from Ag nanoparticles
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. Experimental section
.1. Synthesis of GO-Ag-C
All the reagents were obtained from Sinopharm Chemical Reagent
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H Ag O
⁎
Correspondence to: L. Tian, Hubei Collaborative Innovation Center for Advanced
Organochemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and
Applications of Organic Functional Molecules, Hubei University, Wuhan 430062, PR China.
Co., Ltd. and Alfa Aesar, and used without the further purification. GO
was obtained by a modified Hummer's method (see the Supporting ma-
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terial) [16]. The GO-Ag-C H Ag O nanocomposites were synthesized
566-7367/© 2015 Elsevier B.V. All rights reserved.
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