Reduced graphene oxide as an efficient support for
CdS-MoS
2
heterostructures for enhanced
photocatalytic H
2
evolution
Monaam Ben Ali
a,*
, Wan-Kuen Jo
b
, Habib Elhouichet
a
,
Rabah Boukherroub
c
a
D epartement de Physique, Facult e des Sciences de Tunis, Universit e Tunis-El Manar 2092, Tunisia
b
Department of Environmental Engineering, Kyungpook National University, Daegu 702-701, South Korea
c
Univ. Lille1, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520-IEMN, F-59000 Lille, France
article info
Article history:
Received 24 February 2017
Received in revised form
30 May 2017
Accepted 31 May 2017
Available online xxx
Keywords:
CdS-rGO-MoS
2
composite
Hydrothermal
Interfacial adhesion
H
2
evolution
Visible light
abstract
Cadmium sulphide nanorods-reduced graphene oxide-molybdenum sulphide(CdS-rGO-
MoS
2
) composites were successfully synthesized using hydrothermal process for
enhancing the interfacial contact between CdS nanorods and MoS
2
layer. The good contact
between CdS and MoS
2
is important for improving the photocatalytic hydrogen (H
2
) evo-
lution. The morphological and structural studies showed the production of highly pure CdS
phase with nanorod-like structure dispersed on rGO-MoS
2
layer. X-ray photoelectron
spectroscopy (XPS) and Raman results confirmed the reduction of graphene oxide (GO) into
reduced graphene oxide (rGO). The higher photocurrent density of CdS-rGO-MoS
2
com-
posites compared to CdS/MoS
2
and the fluorescence quenching observed for this com-
posite provided some evidence for an inhibition of electron-hole recombination, which
leads to a longer life time of the photogenerated carriers. Fast electron transfer can occur
from CdS nanorods by the bidimensionnel rGO area to MoS
2
layer due to the intimate
interfacial contact. Composite CdS-rGO-MoS
2
with 20 wt% rGO was found to be the most
effective photocatalyst for H
2
evolution (7.1 mmol h
1
g
1
). The good photocatalytic per-
formance arose from the positive synergistic effect between CdS, rGO and MoS
2
elements.
© 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Introduction
Photocatalytic H
2
production using non noble metals and
earth-abundant elements (metal oxides, sulfides …) has
received much attention as a green, economical, and prom-
ising way to convert solar energy into preservable H
2
[1e3].
Thus, the development of efficient visible-light-driven pho-
tocatalysts is of great importance, because of their useful ab-
sorption of the solar spectrum. CdS as n-type semiconductor
with a narrow band gap (2.4 eV) has been applied for visible
light H
2
evolution due to its suitable conduction band gap edge
for H
2
evolution reaction [4,5]. However, for practical appli-
cations, CdS is still limited by the high photogenerated car-
riers recombination, poor stability, and its photocorrosion [6].
Alternatively, finding novel, environmental-friendly electro-
catalysts with CdS-based substrate has proven to be suc-
cessful way that could hinder the charge carrier
recombination, which greatly improves the catalyst activity
[7e9]. TiO
2
/CdS has been reported as a promising candidate
* Corresponding author.
E-mail address: monaambenali@yahoo.fr (M. Ben Ali).
Available online at www.sciencedirect.com
ScienceDirect
journal homepage: www.elsevier.com/locate/he
international journal of hydrogen energy xxx (2017) 1 e10
http://dx.doi.org/10.1016/j.ijhydene.2017.05.225
0360-3199/© 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Ben Ali M, et al., Reduced graphene oxide as an efficient support for CdS-MoS
2
heterostructures for
enhanced photocatalytic H
2
evolution, International Journal of Hydrogen Energy (2017), http://dx.doi.org/10.1016/j.ijhydene.2017.05.225