CeOx-modified RhNi nanoparticles grown on rGO as highly efficient catalysts for complete hydrogen generation from hydrazine borane and hydrazine

Article abstract of DOI:10.1039/c5ta06197k

CeO_x-modified RhNi nanoparticles (NPs) grown on reduced graphene oxide (rGO) (RhNi@CeO_x/rGO) have been facilely prepared and successfully used as highly efficient catalysts for the rapid and complete hydrogen generation from aqueous solution of hydrazine borane (N₂H₄BH₃) and hydrazine (N₂H₄), respectively. It was found that the CeO_x-doped RhNi NPs with a size of around 3.5 nm were highly dispersed on rGO nanosheets. Among all the catalysts investigated, the optimized catalyst Rh_0.8Ni_0.2@CeO_x/rGO with a CeO_x content of 13.9 mol% exhibited the highest catalytic performance. The total turnover frequency (TOF) of Rh_0.8Ni_0.2@CeO_x/rGO for hydrogen generation from N₂H₄BH₃ reached 666.7 h^-1 (mol_H2 mol_(Rh+Ni)^-1 h^-1) at 323 K, which was among the highest of all the catalysts reported to date for this reaction, 10-fold higher than that of the benchmark catalyst Rh_0.8Ni_0.2, and 3-fold higher than that of Rh_0.8Ni_0.2 with a CeO_x dopant (Rh_0.8Ni_0.2@CeO_x) and a rGO support (Rh_0.8Ni_0.2/rGO). Even at room temperature, Rh_0.8Ni_0.2@CeO_x/rGO can achieve a complete hydrogen generation from N₂H₄BH₃ and N₂H₄ with a TOF value of 111.2 and 36.4 h^-1. This excellent catalytic performance might be attributed to the synergistic structural and electronic effects of the RhNi NPs, CeO_x dopant, and rGO support. Moreover, this general method can be easily extended to facile synthesis of other metal/rGO systems with the doping of rare-earth oxides for more applications.

Full text of DOI:10.1039/c5ta06197k

View Article Online
View Journal
Journal of
Materials Chemistry A
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: Z. Zhang, Z. Lu, H.
Tan, X. Chen and Q. Yao, J. Mater. Chem. A, 2015, DOI: 10.1039/C5TA06197K.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the Ethical guidelines still
apply. In no event shall the Royal Society of Chemistry be held
responsible for any errors or omissions in this Accepted Manuscript
or any consequences arising from the use of any information it
contains.
www.rsc.org/materialsA

Please do not adjust margins
Journal of Materials Chemistry A
Page 1 of 10
View Article Online
DOI: 10.1039/C5TA06197K
Journal Name
ARTICLE
CeO -Modified RhNi Nanoparticles Grown on rGO as Highly
x
Efficient Catalysts for Complete Hydrogen Generation from
Hydrazine Borane and Hydrazine
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
Zhujun Zhang, Zhang-Hui Lu,* Hongliang Tan, Xiangshu Chen,* Qilu Yao
www.rsc.org/
CeO
prepared and successfully applied as highly efficient catalyst for the rapid and complete hydrogen generation from
aqueous solution of hydrazine borane (N BH ) and hydrazine (N ), respectively. It was found that the CeO -doped RhNi
NPs with a size of around 3.5 nm were highly dispersed on rGO nanosheet. Among all the catalysts investigated, the
optimized catalyst Rh0.8Ni0.2@CeO /rGO with CeO content of 13.9 mol% exhibited the highest catalytic performance. The
total turnover frequency (TOF) of Rh0.8Ni0.2@CeO
x x
-modified RhNi nanoparticles (NPs) grown on reduced graphene oxide (rGO) (RhNi@CeO /rGO) have been facilely
2
H
4
3
2
H
4
x
x
x
-
1
x
/rGO for hydrogen generation from N
∙mol(Rh+Ni) ∙h ) at 323 K, which was among the highest of all the catalysts reported to date for this reaction, 10-fold
higher than the benchmarked catalyst Rh0.8Ni0.2, 3-fold higher than Rh0.8Ni0.2 with CeO dopant (Rh0.8Ni0.2@CeO ) and rGO
support (Rh0.8Ni0.2/rGO). Even at room temperature, Rh0.8Ni0.2@CeO /rGO can achieve a complete hydrogen generation
with a TOF value of 111.2 and 36.4 h . This excellent catalytic performance might be attributed to
the synergistic structural and electronic effect of RhNi NPs, CeO dopant, and rGO support. Moreover, this general method
2 4 3
H BH reached 666.7 h
-1
-1
(mol
H2
x
x
x
-1
2 4 3 2 4
from N H BH and N H
x
can be easily extended to facile synthesis of other metal/rGO systems with the doping of rare-earth oxides for more
applications.
of its high GHSC of (8.0 wt %), simple byproduct (N ) and safe
2
1
7-35
Introduction
handling.
The theoretical GHSC of N H BH or N H4 is
2 4 3 2
higher than these of benchmarked hydrogen storage systems
6
NaBH −4H O (7.3 wt %) and NH BH −4H O (5.9 wt %). In
The search for effective on-board hydrogen storage materials
with the combination of high gravimetric/volumetric hydrogen
density and appropriate kinetics remains one of the most
challenging barriers on the road to a “hydrogen economy”
4
2
3
3
2
order to maximize the efficacy of N H BH or N H4 as a
3
2
4
2
hydrogen storage material, the incomplete decomposition of
to NH by another pathway Eq. (3) should be avoided. A
1
-5
N
2
H
4
3
society.
Recent developments in this direction have
BH ) and hydrazine (N ) as
number of noble and non-noble metal based bi-metallic
catalysts have recently been developed and applied in these
reactions. However, most of these catalysts show a poor
suggested hydrazine borane (N
2
H
4
3
2 4
H
6
the promising materials for hydrogen storage. Hydrazine
borane, a stable and safe solid at room temperature having
hydrogen content as high as 15.4 wt%, can be prepared by a
reaction of hydrazine hemisulfate with sodium borohydride in
3
6,37
activity and reusability,
application. Accordingly, the search for novel heterogeneous
catalysts with enhanced catalytic performance for NH -free H
which will limit their further
7
-16
3
2
dioxane.
from N
decomposition of the N
A promising approach for complete H
BH is by hydrolysis of the BH group and selective
moiety of N BH to H and N (Eq.
1) and (2)), corresponding to a theoretical gravimetric
hydrogen storage capacity (GHSC) of 10.0 wt% for the system
BH −3H O. Hydrazine (N ), which is a liquid over a wide
range of temperatures (219-392 K), is considered as
2
generation
production from N H BH or N H is of current research
2
4
3
2 4
2
H
4
3
3
interest.
2
H
4
2
H
4
3
2
2
1
0
(
N H BH (s) + 3H O(l)
3
→
N H (l) + H BO (l) + 3H (g)
3
(1)
(2)
(3)
2
4
2
2
4
3
2
N H (l)
2
→
→
N (g) + 2H (g)
2 2
4
N
2
H
4
3
2
2 4
H
a
3N H (l)
2
4NH (g) + N (g)
3 2
4
promising liquid chemical hydrogen storage material because
Recent studies demonstrated that the catalytic activity of
nickel-based catalysts could be greatly enhanced by doping
3
8-45
with a small amount of cerium oxide.
For example, in
a.
Jiangxi Inorganic Membrane Materials Engineering Research Centre, College of
Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang
contrast to pure Ni NPs, the Ni NPs modifying with a small
amount of CeO2 displayed a 3-fold increase of TOF and an
enhancement of hydrogen selectivity from 67% to 99% for
3
30022, China. Email: luzh@jxnu.edu.cn; cxs66cn@jxnu.edu.cn
Electronic Supplementary Information (ESI) available: Experimental details for
synthesis BH XRD, Raman, FTIR, XPS, MS and NMR patterns. See
4
6
N
2
H
4
3
;
hydrogen generation from N H aqueous solution. Besides,
4
2
DOI: 10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
Journal of Materials Chemistry A
Page 2 of 10
View Article Online
DOI: 10.1039/C5TA06197K
ARTICLE
Journal Name
we found that an amorphous Ni0.9Pt0.1-CeO
2
NPs displayed a the contents. Then, 4.8 mg of NiCl
RhCl ∙3H O and 7.0 mg of Ce(NO ∙6H
Yet, to maximize the above suspension. The suspension was under vigorous
catalytic activity and stability of the active metal NPs, a magnetic stirring for 60 min. After that, 30 mg of NaBH was
suitable support is required to well immobilize and disperse quickly poured into the reactor under rapid magnetic stirring
the active NPs. Owing to its inherent advantages such as for 20 min, resulting in the generation of Rh0.8Ni0.2@CeO /rGO
2
∙6H
2
O, 16.74 mg of
much higher activity than that of Ni0.9Pt0.1 NPs without CeO
2
3
2
3
)
3
2
O were added to the
4
7
2 4 3
for hydrogen generation from N H BH .
4
x
fantastic thermal/electrical conductivity, light weight, excellent (13.9 mol% Ce) NCs as a black suspension, which was then
flexibility, and mechanical strength, reduced graphene oxide directly used for the catalytic reactions. The synthesis of
(
x
rGO) has been applied as an ideal substrate for high- RhNi@CeO /rGO NCs with different bimetallic compositions
4
8-50
performance catalysts.
The anchoring of NPs on rGO (Ni, Rh0.1Ni0.9, Rh0.3Ni0.7, Rh0.5Ni0.5, Rh0.7Ni0.3, Rh0.9Ni0.1, Rh) are
nanosheet could be capable of facilitating the electron transfer following the above process by changing the initial molar ratio
and mass transport kinetics during the catalytic reaction of metal salts. To discuss the effect of Ce, the
x
process. In this case, the combination of cerium oxide, rGO Rh0.8Ni0.2@CeO /rGO NCs with different molar content of Ce
and active metal NPs may lead to an enhanced catalytic (Ce/(Rh+Ni+Ce) = 7.5, 13.9, 18.7, 24.4 and 31.6 mol%) were
activity as well as selectivity and stability during the catalytic also prepared by the same method by altering the initial
process.
Herein, CeO
nanosheet (RhNi@CeO
amount of Ce(NO3)3∙6H
-doped RhNi NPs anchored on rGO The Rh0.8Ni0.2/rGO, Rh0.8Ni0.2@CeO
/rGO) were successfully prepared via a samples were also synthesized by the same methods.
2
O (3.5, 7.0, 10.0, 14.0 and 20.0 mg).
x
x
, Rh0.8Ni0.2, rGO and CeO
x
x
one-step co-reduction approach. The rGO nanosheet was Catalysts characterization
proved to be a distinct support and effective dispersing agent
The crystal phase properties of the synthesized nanocatalysts
were analyzed with a Rigaku RINT-2200 X-ray diffractometer
for anchoring the RhNi@CeO
amorphous CeO could decrease the crystallinity of RhNi alloy
NPs. In comparison with the pure Rh0.8Ni0.2 alloy NPs,
x
NPs, while the doping of
x
(
XRD) using Cu Kα radiation at 40 kV and 40 mA. The
morphologies and sizes of the samples were determined by
using a transmission electron microscope (TEM, Tecnai G2 F20)
equipped with energy dispersed X-ray detector (EDX) for
elemental analysis. One or two droplets of the synthesized
catalyst suspension were deposited on a carbon coated copper
grid for the TEM characterization. Atomic Force Microscopy
Rh0.8Ni0.2@CeO
Rh0.8Ni0.2@CeO
x
and the Rh0.8Ni0.2/rGO catalysts, the obtained
/rGO nanocomposites (NCs) exhibits a much
x
higher catalytic activity and prominent stability for selective
hydrogen generation from N BH or N aqueous solution
without NH impurity.
2
H
4
3
2 4
H
3
(
AFM) measurements were carried on a FSM-Precision FM-
Nanoview 1000 AFM. The specific surface area measurements
were performed with N adsorption/desorption isotherms at
Experimental
2
Materials
liquid nitrogen temperature (77 K) after dehydration under
vacuum at 100 °C for 8 h using BELSORP-mini II. Raman spectra
were collected with a confocal Raman microscope (LabRAM
HR). FTIR spectra were carried out at room temperature by
using a Thermo Nicolet 870 instrument using KBr discs in the
Sodium borohydride (NaBH
4
, 98%), 1, 4-dioxane (99.8%) and
∙6H O, 99.5%) were
purchased from J&KCHEMICAL®. Rhodium chloride hydrate
RhCl ∙3H O, 99.95%) and hydrazine monohydrate (N ∙H O,
8.0%) were bought from Alladin. Hydrazine hemisulfate salt
∙1/2H SO ) and n-pentane (99.5%) were obtained from
Sigma Aldrich. Nickel (II) chloride hexahydrate (NiCl ∙6H O,
8.0%), sodium hydroxide (NaOH, 96.0%), and hydrochloric
cerium (III) nitrate hexahydrate (Ce(NO
3
)
3
2
(
3
2
2
H
4
2
-1
5
00-4000 cm region. X-ray photoelectron spectroscopy (XPS)
9
measurements were performed with a Thermo scientific
ESCALAB 250 multifunctional imaging electron spectrometer.
(N
2
H
4
2
4
2
2
≥
Mass analysis of the generated gases from N
2 4 3
H BH over
9
≥
Rh0.8Ni0.2@CeO
x
/rGO was performed using a Balzers Prisma
acid (HCl, 36%~37%) were provided by Sinopharm Chemical
Reagent Co., Ltd. Hexadecyltrimethylammonium bromide-
QMS 200 mass spectrometer.
Catalytic reactions
aided
(CTAB,
CH
3
(CH
2
)
15N(Br)(CH
3
)
3
,
≥
96.0%),
myristyltrimethylammonium bromid (TTAB, C17
H
38BrN) and The catalytic activity of the as-synthesized RhNi@CeO /rGO,
x
polyvinylpyrrolidone (PVP) was got from Fluka. All chemicals Rh0.8Ni0.2/rGO, Rh0.8Ni0.2@CeO , Rh0.8Ni0.2, rGO and CeOx
x
were used as obtained. We use ordinary distilled water as the towards hydrogen release from aqueous solution of N H BH
3
2
4
reaction solvent. The synthesis and characterization of or N H was evaluated in a typical water-filled graduated
2
4
N H BH (>99%) have been described in our previous burette system. Typically, the reactor containing the catalyst
2 4 3
4
7,50,51
paper.
Synthesis of catalysts
suspension and NaOH (0.5 M) is placed in a water bath
thermostated at 50 °C and connected to a water-filled inverted
burette. A trap filled with HCl (0.1 M) solution is placed
between the reactor and the inverted burette to eliminate the
x
The RhNi@CeO /rGO NCs were facilely prepared by co-
reduction of graphene oxide (GO) and the metal precursors
using sodium borohydride as a reducing agent. In a typical
synthetic procedure, 5 mL aqueous solution containing 10 mg
influence of any evolving ammonia (NH
sealed with a silicon septum. To start the catalytic reaction,
BH or N ∙H O (n(Rh+Ni)/n(N BH ) or n(N )=0.1) is
added into the reactor and the volume of H along N is
3
). The flask is well
4
8-50
N
2
H
4
3
2
H
4
2
2
H
4
3
2 4
H
of GO synthesized by a modified Hummers method
and 15
mg of CTAB were ultrasoniced for 5 min to fully homogenize
2
2
2
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 10
Jou al of Materials Chemistry A
Pr nl ease do not adjust margins
View Article Online
DOI: 10.1039/C5TA06197K
Journal Name
ARTICLE
measured, from which the molar ratio
λ
= n(H
2
+N
2
)/n(N
2
H
4
BH
) for
can evaluated on the basis
B(OH) + (3+2 )H
3
)
or
hydrogen generation from N
of the equation: N BH + 3H
+1)/3N + 4(1- )/3NH
equations (1), (2) and (3). Therefore, the selectivity is defined
as Eq. (4). The selectivity towards H generation from
decomposition of N ) can be calculated by using Eq. (5).
2 2 2 4
γ = n(H +N )/n(N H ) can be obtained. The selectivity (α
H
2 4
BH
3
2
H
4
3
2
O
→
3
α
2
+
(2α
2
α
3
, which could be deduced from the
2
2 4
H (β
(
4)
(
5)
Durability and reusability test
The durability of the Rh0.8Ni @CeO /rGO NCs was tested:
Fig.
1 Powder XRD patterns of the obtained GO, rGO, Rh0.8Ni0.2,
0.2
x
Rh0.8Ni0.2/rGO, Rh0.8Ni0.2@CeO and Rh0.8Ni0.2@CeO /rGO samples.
x
x
after the first cycle of hydrogen generation reaction was
completed, another equivalent of N H BH or N H ∙H O was
2
4
3
2
4
2
added into the reaction system and the gas released was
monitored by the gas burette. It should be noted that an
excess amount of NaOH (2.0 M) was used in this recycle test
seeds for the successive growth of RhNi@CeO hybrid NPs.
x
CTAB plays a role as a dispersing agent and stabilizer for the
synthesis of uniform RhNi@CeO /rGO. The synthesized
x
for hydrogen generation from N H BH , due to the
3
2
4
RhNi@CeO /rGO NCs were used as catalysts for hydrogen
x
neutralization of NaOH by the hydrolysate (H BO ) reuslted
3
3
release from N H BH or N H aqueous solution. The
2 4
2
4
3
from the first step (-BH3 hydrolysis) of N H BH
2
4
3
Rh0.8Ni0.2@CeO /rGO NCs exhibited the highest activity among
x
5
0
dehydrogenation reaction. The reactions were repeated for
six runs under the same conditions as the first cycle. Then, the
catalyst was separated from the reaction solution by
centrifugation, washed by water and recycled for the same
catalytic reactions under the same conditions.
all the samples tested (vide infra), and therefore, were chosen
as the model catalyst for full instrument characterization.
The synthesized nanocatalysts were isolated by
centrifugation from the reaction solution, washed by water
and following dried in vacuum oven for characterization
experiments.
The
powder
XRD
patterns
of
Rh0.8Ni0.2@CeO /rGO,
x
Rh0.8Ni0.2/rGO,
Rh0.8Ni0.2@CeOx,
Results and discussion
Rh0.8Ni0.2, rGO, and GO are shown in Fig. 1. The most intense
peak at around 2θ = 10.2° corresponding to the (001)
reflection of GO disappeared at the rGO and rGO-containing
samples, and a new peak at around 2θ = 21.4° was observed,
indicating that GO was successfully reduced to rGO during the
synthetic process. As shown in Fig. 1, all the RhNi containing
Synthesis and characterization of catalysts
x
The CeO -doped RhNi alloy NPs were facilely grown on rGO
nanosheet via a one-step co-reduction approach (Scheme 1).
Typically, the metal salts with different molar ratio were firstly
impregnated on GO nanosheets with the help of magnetic
samples (Rh0.8Ni0.2
,
Rh0.8Ni0.2/rGO, Rh0.8Ni0.2@CeOx and
stirring and CTAB. To our knowledge, Ce(NO
3 3
) is very unstable
Rh0.8Ni0.2@CeO /rGO) exhibited a crystalline peak centered at
x
in alkaline solution and can be easily hydrolyzed to Ce(OH)
3
,
3
+
around 2θ = 41.2°, which was between the fcc (111) diffraction
peaks of Rh (PDF#05-0685) and Ni (PDF#04-0850), indicating
then the redox reaction between Ce(OH)
lead to the formation of CeO (eqn. (S1) and (S2)). Here,
NaBH serve as a reducing agent for the reduction of metal salt
and GO, while the hydrolysate (NaB(OH) ) of NaBH provided
the alkaline environment for the formation of CeO . As the
amorphous CeO and RhNi alloy may be formed almost
simultaneously, the formed RhNi or CeO served as the in situ
3 2
and Rh or O will
5
2
x
the formation of RhNi alloy. In addition, the CeO -doped
x
4
samples (Rh0.8Ni0.2@CeO and Rh0.8Ni0.2@CeO /rGO) showed a
x
x
4
4
broad and weak peak at around 2θ = 28.2°, which can be
x
assigned to the amorphous state of CeO . In particular, these
x
x
samples displayed a weaker RhNi alloy signal than these of the
x
samples without the doping of CeO
Rh0.8Ni0.2/rGO), which probably due to the fact that the doping
of amorphous CeO into the ultrafine nanocrystalline of
x
(Rh0.8Ni0.2 and
x
Rh0.8Ni0.2 can disturb the long-range order of the Rh0.8Ni0.2
nanoalloy and thus decrease its crystallinity. Furthermore, the
formed RhNi alloy are inclined to bind more strongly to the
3
3
x
distortions and vacancies of the amorphous CeO . As a result,
the ligand and strain effect around these sites may further lead
to the disorder of the RhNi nanoalloy, and finally decrease the
crystallinity of bimetal NPs. Besides, from the powder XRD
Scheme
RhNi@CeO
1
Schematic illustration of preparation of the
x
/rGO NCs.
patterns of RhNi@CeO
x
/rGO NCs with different molar content
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
Journal of Materials Chemistry A
Page 4 of 10
View Article Online
DOI: 10.1039/C5TA06197K
ARTICLE
Journal Name
metallic NPs were highly dispersed on the rGO nanosheet with
average particle size of around 3.5 nm (Fig. 2a and Fig. S2).
Similar particle size and dispersity were observed in
Rh0.8Ni0.2/rGO NCs (Fig. 2c), thus illustrating that the doping of
Rh0.8Ni0.2/rGO with CeO
growth of Rh0.8Ni0.2 NPs. However, the Rh0.8Ni0.2@CeO
prepared without GO were aggregated to a bigger size (about
nm), as shown in Fig. 2d. This is understandable because the
x
did not influence the distribution and
x
NPs
5
hydrophilic phenyl epoxide and hydroxyl group and the
hydrophobic basal plane of GO play a role as a surfactant,
which can effectively anchor the metal NPs in special areas and
thus control their distribution and agglomeration on the rGO
5
0,53
nanosheet during the synthesis process.
The high
resolution TEM image of Rh0.8Ni0.2@CO /rGO (Fig. 2b) shows
x
that the metal NPs are in crystalline state with a d-spacing of
0.218 nm, which differs from the fcc (111) plane of Rh (0.228)
and Ni (0.214 nm), and thus further confirms the formation of
RhNi alloy. The corresponding SAED patterns show that the
CeO -doped
x
samples
(Rh0.8Ni0.2@CeOx
and
Rh0.8Ni0.2@CeO /rGO) exhibit a lower degree of crystallinity
x
Fig. 2 TEM images and the corresponding SAED patterns (inset) for (a)
/rGO, (c) Rh0.8Ni0.2/rGO and (d) Rh0.8Ni0.2@CeO
/rGO.
(
inset of Fig. 2a and 2d) than that of the sample without CeOx
Rh0.8Ni0.2@CeO
The high-resolution TEM image of Rh0.8Ni0.2@CeO
x
x
; (b)
x
(Rh0.8Ni0.2/rGO) (inset of Fig. 2c), which is in agreement with
the powder XRD results (Fig. 1). The high-angle annular dark-
field scanning transmission electron microscopy (HADDF-STEM)
of Rh (Fig. S1), it was found that the samples with Rh content and the elemental mapping images for Rh0.8Ni @CeO /rGO
0.2
x
ranging from 0 to 30 mol% (sample a, b and c) were in (Fig. 3a and b) show that the metallic elements Rh, Ni, and Ce
amorphous state, whereas the samples with a higher content are homogeneous dispersed in these NPs. Furthermore, the
of Rh (50-100 mol%, sample d, e, f and g) showed a weak energy-dispersive X-ray spectroscopy (EDX) spectrum further
crystalline peak of RhNi alloy or Rh. Herein, we believed that confirms the existence of Rh, Ni and Ce elements (Fig. S3). The
the doping of amorphous CeO
crystalline of Ni based bimetallic NPs with a small quantity of Table S1), quite close to their initial contents.
noble-metal containing to the amorphous state, as reported
The GO used for the synthesis of catalysts was
and can also effectively decrease characterized by using AFM measurement. The AFM results
x
can effectively transform the atomic ratio for Rh:Ni:Ce was detected by ICP-AES (shown in
3
3,47
x
before for Ni0.9Pt0.1-CeO ,
the crystallinity of Ni-based bimetallic NPs with a majority of show that the average thickness of the GO nanosheets is about
noble-metal containing. The RhNi NPs in amorphous state or 1.25 nm (Fig. S4), suggesting 2-4 layers of GO. Fig. S5 shows
with a low degree of crystallinity have the features of short-
range order and long-rang disorder, and both these features
might contribute to enhance their catalytic performance.
The morphologies and size of the synthesized
x x
Rh0.8Ni0.2@CeO /rGO, Rh0.8Ni0.2@CeO and Rh0.8Ni0.2/rGO were
characterized by TEM and selected-area electron diffraction
x
(SAED) (Fig. 2). As for the Rh0.8Ni0.2@CeO /rGO NCs, all the
x
Fig. 4 (a) The survey XPS spectrum of Rh0.8Ni0.2@CeO /rGO NCs; XPS
spectra of (b) Rh 3d and (c) Ni 2p and (d) Ce 3d for the synthesized
catalysts.
x
Fig. 3 (a) TEM image of Rh0.8Ni0.2@CeO /rGO; (b) HADDF-STEM and
x
the EDX mapping images of Rh0.8Ni0.2@CeO /rGO.
4
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 10
Journal Name
Jou al of Materials Chemistry A
Pr nl ease do not adjust margins
View Article Online
DOI: 10.1039/C5TA06197K
ARTICLE
the Raman and FTIR spectra of GO and Rh0.8Ni0.2@CeO
can be seen from Raman spectra (Fig. S5a) that the as- compared to that of samples prepared by using a low
synthesized GO and Rh0.8Ni0.2@CeO /rGO both exhibit two concentration of CTAB (7.5-15mg) (Fig. S8b and c). The high
x
/rGO. It without CTAB have a bigger particle size (Fig. S8a), as
x
1
-
peaks centered at 1335 and 1597 cm , corresponding to the D CTAB concentrations may hinder the impregnation of metal
5
4
and G bands of carbon products, respectively. The intensity precursors onto GO nanosheets and finally resulting in the
ratio of the D to G band (I /I ) of GO is increased from 1.02 to generation of ununiform RhNi@CeO particles with poor
.21 after loading of the Rh0.8Ni0.2@CeO NPs. The relative dispersity on rGO nanosheets (Fig S8d). From the XRD patterns
changes in I /I is due to the increase in the number of smaller of the samples prepared with high CTAB concentrations (25-35
graphene domains after reduction of GO. As shown in FTIR mg), the diffraction peaks of CTAB are also observed (Fig. S9),
spectra of GO and Rh0.8Ni0.2@CeO /rGO (Fig. S5b), it can be thus indicating the rGO nanosheets and the active metal NPs
seen clearly that the C=O peak at 1735 cm , the C-OH peak at could be coated by CTAB. Other surfactants, such as PVP and
D
G
x
1
x
D
G
5
5
x
-1
-
1
-1
1
224 cm and the C-O peak at 1053 cm of GO disappeared TTAB, can also be used for the synthesis of RhNi@CeO
x
/rGO
after loading of Rh0.8Ni0.2@CeO NPs, further indicating that NCs with similar compositions and particle sizes as confirmed
x
the GO was reduced to rGO during the synthetic process. by their XRD patterns and TEM images (Fig. S10). Besides, the
Additionally, the XPS results for C 1s show that the intensities influence of different stirring time (0.5-6 h) during the
of the oxygen containing functional groups (such as –C-O, -C=O, preparation of RhNi@CeO
x
/rGO NCs is not so distinct (Fig. S11).
-
COO) of GO (Fig. S6) decrease significantly after the formation Only the sample prepared without stirring during the
5
6
of Rh0.8Ni0.2@CeO
of GO.
x
/rGO, which also indicates the reduction impregnation period show a degree of agglomeration in
certain areas of the TEM image (Fig. S11a). The
x x
XPS analyses after Ar sputtering for RhNi@CeO /rGO, RhNi@CeO /rGO NCs prepared in different conditions, such as
RhNi@CeO and RhNi/rGO were also performed to understand different CTAB concentrations and stirring time, have a similar
x
2
-1
the electronic states and surface interaction among Rh, Ni, Ce, and low specific surface area of around 25 m g (Fig. S12). It is
and rGO. The characteristic signals of metal state of Rh and Ni hard to reflect the real specific surface area of
x x x
and CeO were detected from the sample of RhNi@CeO /rGO. RhNi@CeO /rGO NCs as prepared in the reaction solution,
0
The signals corresponding to Rh in the Rh 3d5/2 and 3d3/2 probably due to the overlapping of graphene sheets within the
levels appear at the binding energies (BEs) of 307.1 and 311.9 self-aggregation during the drying process. To examine the
0
eV, respectively (Fig. 4b). And the signals for Ni can be magnetism of the Rh0.8Ni0.2@CeO
x
/rGO, we have directly using
detected in the Ni 2p3/2 and Ni 2p1/2 levels with BEs of 852.8 a magnet to contact the flask containing the catalyst
and 870.1 eV, respectively (Fig. 4c). In addition, it can be seen suspension. However, the catalyst suspension was still
3
+
4+
from the Ce 3d level that both signals of Ce and Ce are uniformly dispersed even after 6 hours (Fig. S13), indicating
found (Fig. 4d). This is probably due to the fact that the oxygen that these catalysts with a low content of Ni have no or only a
defect structure of cerium oxide is dynamic and may change negligible magnetism.
spontaneously in response to physical parameters such as Catalytic performance
temperature, presence of other ions, and partial pressure of
Recent research have shown that the hydrogen selectivity for
5
7
oxygen. The XPS spectra show that there is a negative shift in
the BEs of Rh 3d5/2 and Ni 2p3/2 of RhNi@CeO /rGO NCs as
compared to those of the RhNi@CeO and RhNi/rGO NCs;
whereas a positive shift of the corresponding BE of Ce 3d5/2 is
observed relative to that of Ce and CeO . These shifts in BEs
demonstrate that CeO and rGO nanosheets in the
RhNi@CeO /rGO NCs both act as electron donors for atoms of
Rh and Ni. Such electronic transport between RhNi, CeO , and
rGO in the RhNi@CeO /rGO NCs might enhance their catalytic
activity for N BH and N dehydrogenation. No obvious
signal of B was detected by the survey XPS spectrum of
/rGO (Fig. 4a). The high resolution of B 1s for
both the RhNi@CeO /rGO, RhNi@CeO and RhNi/rGO samples
show a week signal at around 192.4 eV of oxidized boron (Fig.
S7), probably due to a very small residual hydrolysate of NaBH
decomposition of N
NaOH, which can not only accelerate the rate-determining
deprotonation step (N *) (thus promoting reaction
kinetics), but can also restrain the generation of the basic
2 4
H can be promoted in the presence of
x
x
2 4 2 3
H →N H
2
O
3
2
6,47,50
byproduct NH
hydrogen generation from N
presence of Rh0.8Ni0.2@CeO /rGO was determined to be 0.5 M
Fig. S14). The catalytic performance of the catalyst was
3
.
The optimum concentration of NaOH for
x
2
H
4
BH (200 mM, 5 mL) in the
3
x
x
x
(
x
evaluated based on the volumetric and reaction time
measurement of the amount of gases released during the
reaction. As shown in Fig. 5, the catalytic performances of the
2
H
4
3
2 4
H
Rh0.8Ni0.2@CeO
x
Rh0.8Ni0.2
,
Rh0.8Ni0.2/rGO,
Rh0.8Ni0.2@CeO
x
and
/rGO nanocatalysts have been investigated for
hydrogen generation from N BH (0.5 M NaOH) at 323 K.
The pure Rh0.8Ni0.2 NPs can only generate 5.4 equiv. (H +N
per N BH (λ = 5.4, α = 77.5%) in about 43 min. After the
Rh0.8Ni0.2 NPs were immobilized on the rGO support or doped
with the amorphous CeO , the catalytic activity and hydrogen
selectivity were enhanced greatly, with which 6.0 and 5.8
equiv. (H +N ) per N BH (α = 100% and 93.6%) released in
only 14.5 and 12.8 min, respectively. Clearly, the rGO support
x
x
Rh0.8Ni0.2@CeO
x
2
H
4
3
4
2
2
)
in the samples. As no elemental B or Ni-B or Rh-B signals were
observed from B 1s spectrum, we therefore infer that there is
no or negligible electronic synergistic effect between B, Ni and
Rh.
2
H
4
3
x
In this work, CTAB plays a role as a dispersing agent and
2
2
2
H
4
3
stabilizer for preparing the uniform RhNi@CeO
x
/rGO NCs. The
TEM images (Fig. S8d) show that rGO supported RhNi@CeO
x
or the CeO
x
dopant was inactive for this reaction (Fig. S15). The
NPs prepared by using a high concentration of CTAB (35 mg) or
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Please do not adjust margins
Journal of Materials Chemistry A
Page 6 of 10
View Article Online
DOI: 10.1039/C5TA06197K
ARTICLE
Journal Name
mass spectrometric analysis (Fig. S16), indicating a 100%
hydrogen selectivity. The total turnover frequency (TOF) of
-
1
-1 -1
Rh0.8Ni0.2@CeO
x
/rGO reached 666.7 h (mol
which was 10-fold higher than the benchmarked catalyst
3-fold higher than Rh0.8Ni0.2@CeO and
H
2
∙mol(Rh+Ni) ∙h ),
Rh0.8Ni0.2
,
x
Rh0.8Ni0.2/rGO. To the best of our knowledge, this is the highest
value reported to date for this reaction at 323 K (Table S2).
Even at room temperature (303 K), the Rh0.8Ni0.2@CeO
x
/rGO
NCs exhibited the complete hydrogen generation from
-1
2 4 3
N H BH with a TOF value of 112.2 h (vide infra). As far as we
know, only one nanocatalyst (Ni0.6Pt0.4/MSC-30) has been
reported to exhibit a 100% hydrogen selectivity and high
activity toward complete conversion of N H BH to hydrogen
2
4
3
6
at room temperature, and Rh0.8Ni0.2@CeO /rGO is the second
x
Fig. 5 Time course plots for H
2
generation from N
2
H
4
BH
3
(200 mM, 5
, and
) = 0.1) with
NaOH (0.5 M) at 323 K. (inset) The structure simulation of the catalyst
and corresponding total TOF value of H
one. The catalytic activity of Rh0.8Ni0.2@CeO /rGO for hydrogen
x
mL) over Rh0.8Ni0.2@CeO
x
/rGO, Rh0.8Ni0.2/rGO, Rh0.8Ni0.2@CeO
BH
x
Rh0.8Ni0.2 catalysts (13.9 mol% Ce; n(Ni+Rh)/n(N
2
H
4
3
generation from N H BH at room temperature was lower than
3
2
4
that of Ni0.6Pt0.4/MSC-30.
2
.
The RhNi@CeO /rGO NCs with different metal
x
compositions have been tested for hydrogen generation from
N H BH (0.5 M NaOH) at 323 K (Fig. 6). The catalytic activity
2
4
3
enhanced catalytic performance of Rh0.8Ni0.2 NPs grown on and selectivity were strongly dependent on the Rh/Ni ratio.
rGO can be reasonable due to the combined effect of excellent Both monometallic Rh@CeO /rGO and Ni@CeO /rGO NCs
dispersion and the intimate interaction derived from rGO. In showed a certain activity, with which 4.6 equiv. (H +N ) per
x
x
2
2
addition, the Rh0.8Ni0.2 alloy NPs modified by amorphous CeO
x
N H BH released (λ = 4.6, α = 47.5%) in 3.8 and 61.0 min,
2 4 3
shows a very low crystallinity and thus have the high respectively (Fig. 6a). All the RhNi@CeO /rGO catalysts with
x
concentration of unsaturated coordination sites, which can different bimetallic compositions exhibited a high catalytic
selectivity. activity and hydrogen selectivity with more than 5.6 equiv.
85%) (Fig. 6b). Especially, the
effectively improve the catalytic activity and H
2
Similar synergistic effects were also observed in our previous gases released (λ ≥ 5.6, α
4
≥
7
50
work for Ni0.9Pt0.1-CeO
reaction.
2
and Ni0.9Pt0.1/graphene in the same Rh0.8Ni0.2@CeO /rGO NCs exhibited the highest catalytic
x
activity with 100% hydrogen selectivity. The enhanced catalytic
Since the catalytic activity can be enhanced by the performance of the RhNi@CeO /rGO NCs demonstrates that
x
modification of bimetallic NPs with addition of CeO
nanosheet, the combination of CeO dopant, rGO support, and the so-called strain and ligand effects is highly required for
bimetallic NPs may realize a better catalytic performance. As the complete hydrogen release from N H BH . Additionally,
x
or rGO the resulting synergistic effect between Rh and Ni induced by
5
8
x
2
4
3
we expected, Rh0.8Ni0.2 NPs with the doping of amorphous when the molar content of Ce is set as the present value of
CeO supported on rGO nanosheet (Rh0.8Ni0.2@CeO /rGO) 13.9 mol%, the resulting Rh0.8Ni0.2@CeO /rGO has the
showed a greatly enhanced catalytic activity towards hydrogen optimum performance (Fig. S17). The catalytic activity of this
generation from N BH with 6.0 equiv. (H +N ) per N BH
catalyst will decrease with the decreasing or increasing the Ce
λ = 6.0, α = 100%) released in only 4.5 min. The H /N ratio of content of 13.9 mol%.
over the
The Rh0.8Ni @CeO /rGO NCs prepared with different
/rGO catalyst was further confirmed by the
x
x
x
2
H
4
3
2
2
2
H
4
3
(
2
2
the
gases
released
from
2 4 3
N H BH
0.2
x
Rh0.8Ni0.2@CeO
x
Fig. 6 Time course plots for H
RhNi@CeO /rGO catalysts with different molar content of Rh (13.9 mol% Ce; n(Ni+Rh)/n(N
2
generation from N
2
H
4
BH
3
(200 mM, 5 mL) over (a) the monometallic Ni@CeO
BH
x x
/rGO and Rh@CeO /rGO catalysts and (b)
) = 0.1) in the presence of NaOH (0.5 M) at 323 K.
x
2
H
4
3
6
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 7 of 10
Jou al of Materials Chemistry A
Pr nl ease do not adjust margins
View Article Online
DOI: 10.1039/C5TA06197K
Journal Name
ARTICLE
The catalytic performance of Rh0.8Ni0.2@CeO
has also been tested for hydrogen generation from N
different temperatures (Fig. 7). The catalytic reactions for H
generation from N BH were completed in 2.0, 4.5, 9.5 and
7.0 min at 333, 323, 313 and 303 K, respectively,
corresponding to TOF values of 1500.0, 666.7, 315.8 and 111.2
x
/rGO NCs
2
H
4
BH at
3
2
2
H
4
3
2
-1
h
(Fig. 7a). Based on the Arrhenius plot fitted by the H
generation rate for the hydrolysis of BH group and the
decomposition of N moiety of N BH at different reaction
temperatures, we can obtain the corresponding activation
energy value a1=17.4 kJ/mol and a2=55.2 kJ/mol, respectively
Fig. 7b). Also, the Rh0.8Ni0.2@CeO /rGO catalysts with different
2
3
2
H
4
2
H
4
3
E
E
(
x
metal concentrations (Rh+Ni: 0.005-0.025 M) were used for
the same reactions (Fig. S23). As expected, the H generation
2
rate of both the hydrolysis and decomposition increases with
increasing catalyst concentration. The plots based on the H2
generation rate versus catalyst concentrations (both in
logarithmic scale) show that a slope of 0.87 and 0.93 is
obtained for the hydrolysis and decomposition reactions,
respectively, implying that both the reactions approximate
first-order kinetics with respect to the catalyst concentration.
The plausible catalytic scheme of hydrazine borane
Fig. 7 Time course plots for H
2
generation from aqueous solution of (a)
/rGO catalysts (13.9 mol%
) = 0.1) at temperatures ranging from
03 to 333 K. Plot of ln k versus 1/T during the releasing of H from (b)
hydrolysis of BH (Part 1) and decomposition of the N moiety of
BH (Part 2) and (d) decomposition of N aqueous solution over
/rGO at different temperatures.
N
2
H
4
BH
3
and (c) N
2
H
4
over Rh0.8Ni0.2@CeO
x
Ce; n(Ni+Rh)/n(N
H
2 4
3
BH or N
2 4
H
3
2
3
2 4
H
N
2
H
4
3
2 4
H
Rh0.8Ni0.2@CeO
x
dehydrogenation over the as-prepared RhNi@CeO /rGO is
x
illustrated in Scheme 2. Firstly, the interaction between the
N H BH molecule and the RhNi@CeO surface will produce
2
4
3
x
CTAB concentrations were also tested for N H BH
3
2
4
the activated complex species, who attack by a H O molecule
2
dehydrogenation (Fig. S18a). The sample prepared without
surfactant show only a little decrease of catalytic activity (TOF:
readily leads to concerted dissociation of the B–N bonding of
N H BH . When the BH group of N H BH is catalytically
-
1
2
4
3
3
2
4
3
4
00 h ) in comparison with the samples prepared with low
hydrolyzed by the catalysts, concurrently, the resulting N H4
2
CTAB concentration (7.5-15mg), probably due to their relative
bigger particle sizes. The samples prepared with high CTAB
concentrations (25-35 mg) exhibited a decrease in catalytic
activity as compared to that of sample with low CTAB
concentration or without surfactant. This is likely due to the
moieties directly interact with metal NPs to generate N and H .
2
2
The kinetic rate for the hydrolysis of the –BH group is much
3
faster than that of the decomposition of N H moiety of
2
4
N H BH
3.
2
4
The Rh0.8Ni0.2@CeO /rGO catalyst was used to
x
fact that the surface of the RhNi@CeO /rGO NCs prepared
x
catalytically decompose the same amount of N H4 as that
2
with high CTAB concentrations were coated by CTAB, and thus
leading to a decrease in the number of exposed active sites.
The catalysts prepared with other surfactants, such as PVP and
TTAB, have a similar catalytic activity as the sample prepared
with CTAB (Fig. S18b). The as-prepared catalyst showed a small
decrease in the activity, after removed the CTAB by thoroughly
washed by ethanol and water (Fig. S19), indicating that the
resulted from the first step of N H BH dehydrogenation
2
4
3
x
rGO nanosheets supported RhNi@CeO NPs can be stabilized
by CTAB. Besides, the stirring time during the impregnation of
metal precursors has no significant influence on catalytic
2 2 4 3
performance towards H generation from N H BH (Fig. S20),
while only the sample prepared without stirring show a little
decrease of activity. To discuss the effects of the residuals
oxygen groups on rGO nanosheets, an excess amount of NaBH
4
was used to reduce the oxygen groups completely, which was
further verified by XPS measurements (Fig. S21). In comparison
with the sample with a few residual oxygen groups (Fig. S6b),
the sample without oxygen groups had almost the same
activity (Fig. S22), thus indicating that a few residual oxygen
groups on rGO nanosheets have negligible effect on the
catalytic performance in the present work.
Scheme 2. Schematic representation of H
over Rh0.8Ni0.2@CeO /rGO catalysts.
2 2 4 3
generation from N H BH
x
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 7
Please do not adjust margins

Please do not adjust margins
Journal of Materials Chemistry A
Page 8 of 10
View Article Online
DOI: 10.1039/C5TA06197K
ARTICLE
Journal Name
2 2 4 3 2 4 x
Fig. 8 Durability and reusability test for H generation from aqueous solution of (a) N H BH and (b) N H (1.0 mmol) catalyzed by Rh0.8Ni0.2@CeO /rGO
2 4 3 2 4
(n(Ni+Rh)/n(N H BH or N H ) = 0.1) at 323 K.
reaction under the same conditions. The completely by the TEM (Fig. S24) and powder XRD characterization (Fig.
decomposition of N at 333, 323, 313 and 303 K can finish in S25).
.0, 5.7, 15.0 and 33.0 min in the presence of
2 4
H
3
x
Rh0.8Ni0.2@CeO /rGO (Fig. 7c), corresponding to total TOF
-
1
Conclusions
values of 400.0, 210.5, 80.0 and 36.4 h , respectively. These
TOF values were relatively high value among all the reported
In summary, RhNi alloy NPs with the doping of amorphous
catalysts for the decomposition of
N
2
H
4
at various
Especially, the present catalyst
release from N at room
x
CeO have been successfully anchored on the surface of rGO
5
9,60
temperatures (Table S3).
can achieve a complete H
nanosheets via a one-step co-reduction synthetic process at
room temperature, and successfully applied as highly efficient
catalyst for the complete hydrogen production from aqueous
2
2 4
H
-1
temperature with a TOF of 36.4 h , which was 5-fold higher
than the benchmarked catalyst Rh0.8Ni0.2 in the previous
solution of N
that CeO and rGO can effectively decrease the crystallinity
and size of RhNi NPs, respectively. The XPS results
demonstrated that CeO and rGO nanosheets in the the
RhNi@CeO /rGO NCs both act as electron donors for Rh and Ni.
Therefore, the modification of the surface electronic structure
2 4 3 2 4
H BH or N H . The TEM and XRD images showed
3
6
literature. The activation energy (
catalyzed by Rh0.8Ni0.2@CeO /rGO was determined to be
8.0 kJ/mol (Fig. 7d), higher than that value (55.2 kJ/mol) of
this catalyst for dehydrogenation of N moiety of N BH
/rGO NCs exhibited a lower catalytic
activity for the decomposition of N than that for the
dehydrogenation of N BH . A plausible explanation is that
when the BH group of N BH is catalytically hydrolyzed by
the catalysts (very fast), concurrently, the resulting N
moieties directly interact with metal NPs to generate N and H
thus promoting the kinetic properties of BH
dehydrogenation. Similar reaction characteristics for Rh
Ea3) for decomposition of
x
N
2
H
4
x
5
x
2
H
4
2
H
4
3
.
x
The Rh0.8Ni0.2@CeO
x
2
H
4
and chemical properties of RhNi@CeO
and ligand effects among Ni, Rh, CeO
NPs through the strain
and rGO is responsible
x
2
H
4
3
x
3
2
H
4
3
x
for the high activity of the RhNi@CeO /rGO NCs. These
2
H
4
2
3
synergistic structural and electronic effects are highly required
,
for the complete hydrogen release from aqueous solution of
2
2 4
N H
N
2
H
4
BH
3
or
N
2
H
4
.
In comparison with the Rh0.8Ni0.2
, Rh0.8Ni0.2/rGO, and most of the catalysts
reported to date, the obtained Rh0.8Ni0.2@CeO /rGO NCs
exhibited a much higher catalytic activity towards hydrogen
generation from N BH and N at 323 K with 100%
,
4
6
Ni and
Rh0.8Ni0.2@CeO
x
,37
Ni0.6Pt0.4/MSC-30 were observed in the previous reports.
x
As the durability and reusability of catalysts is very
important for practical application. In this sense, the durability
2
H
4
3
2 4
H
and reusability of Rh0.8Ni0.2@CeO
generation from aqueous solution of N
were carried out. As shown in Fig. 8, after six cycles, the
/rGO NCs showed a 100% hydrogen selectivity
and productivity, but a little decrease in activity for hydrogen
generation from N BH and N , respectively. However, the
treatment of this catalyst by washing with water leaded to the
x
/rGO NCs for hydrogen
hydrogen selectivity and outstanding durability and reusability.
The catalytic results open up new avenues in the effective
application of hydrazine borane and hydrazine aqueous
solution as the feasible hydrogen storage materials for fuel cell
applications.
2
H
4
BH or N at 323 K
3
2 4
H
Rh0.8Ni0.2@CeO
x
2
H
4
3
2 4
H
recovery of the active sites, which showed almost the same Acknowledgements
activity as the pristine catalysts for hydrogen generation from
This work was financially supported by National Natural
Science Foundation of China (No. 21463012 and 21103074). Z.-
H. Lu was supported by Young Scientist Foundation of Jiangxi
N
2
H
4
BH
had a good durability and reusability in the catalytic reactions.
The good stability of the Rh0.8Ni0.2@CeO /rGO NCs was verified
3 2 4 x
or N H , indicating that the Rh0.8Ni0.2@CeO /rGO NCs
x
8
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 9 of 10
Journal Name
Jou al of Materials Chemistry A
Pr nl ease do not adjust margins
View Article Online
DOI: 10.1039/C5TA06197K
ARTICLE
Province (20133BCB23011) and "Gan-po talent 555" Project of 31 L. He, Y. Huang, X. Y. Liu, L. Li, A. Wang, X. Wang, C. Y. Mou
and T. Zhang, Appl. Catal. B: Environ., 2014, 147, 779-788.
Jiangxi Province.
3
3
3
3
2 J. Zhang, Q. Kang, Z. Yang, H. Dai, D. Zhuang and P. Wang, J.
Mater. Chem. A, 2013, 1, 11623-11628.
3 H. L. Wang, J. M. Yan, Z. L. Wang, S-II. O and Q. Jiang, J.
Mater. Chem. A, 2013, 1, 14957-14962.
4 N. Cao, L. Yang, C. Du, J. Su, W. Luo and G. Cheng, J. Mater.
Chem. A, 2014, 2, 14344-14347.
5 Y. Du, J. Su, W. Luo, G. Cheng, ACS Appl. Mater. Interfaces,
Notes and references
1
O. K. Farha, A. M. Spokoyny, K. L. Mulfort, M. F. Hawthorne,
C. A. Mirkin and J. T. Hupp, J. Am. Chem. Soc., 2007, 129,
1
2680-12681.
D. Pukazhselvan, V. Kumar and S. K. Singh, Nano Energy,
012, 1, 566-589.
C. Fellay, P. J. Dyson and G. Laurenczy, Angew. Chem., 2008
20, 4030-4032.
2
015, 7, 1031-1034.
2
3
4
3
3
6 S. K. Singh, Q. Xu, J. Am. Chem. Soc., 2009, 131, 18032-18033.
7 D. C. Zhong, K. Aranishi, A. K. Singh, U. B. Demirci and Q. Xu,
Chem. Commun., 2012, 48, 11945-11947.
2
,
1
3
8 X. Wang, D. Liu, S. Song, H. Zhang, Chem. Eur. J., 2013, 19,
A. Boddien, D. Mellmann, F. Gärtner, R. Jackstell, H. Junge, P.
J. Dyson, G. Laurenczy, R. Ludwig and M. Beller, Science,
8
9 Y. J. Xu, N. Zhang, Chem. Mater., 2013, 25, 1979-1988.
082-8086.
3
4
2011, 333, 1733-1736.
0 X. Wang, D. Liu, S. Song and H. Zhang, J. Am. Chem. Soc.,
2
5
6
7
8
9
X. Cao, Y. Han, C. Gao, Y. Xu, X. Huang, M. Willander and N.
Wang, Nano Energy, 2014, 9, 301-308.
Q. L. Zhu, D. C. Zhong, U. B. Demirci and Q. Xu, ACS Catal.,
013, 135, 15864-15872.
4
4
4
1 A. Hornés, M. J. Escudero, L. Daza, A. Martínez-Arias, J.
Power Sources, 2014, 249, 520-526.
2 F. Zhu, G. Chen, S. Sun and X. Sun, J. Mater. Chem. A, 2013, 1,
2
014, 4, 4261-4268.
T. Hügle, M. F. Kühnel and D. Lentz, J. Am. Chem. Soc., 2009
31, 7444-7446.
,
2
88-294.
3 A. S. P. Lovόn, J. J. Lovόn-Quintana, G. I. Almerindo, G. P.
Valen a, M. I. B. Bernardi, V. D. Araújo, T. S. Rodrigues, P. A.
Robles-Dutenhefner and H. V. Fajardo, J. Power Sorces, 2012
16, 281-289.
4 X. Wang, D. Liu and S. Song, H. Zhang, J. Am. Chem. Soc.,
013, 135, 15864-15872.
5 M. I. Kim, K. S. Park and H. G. Park, Chem. Commun., 2014
0, 9577-9580.
1
T. He, H. Wu, G. Wu, J. Wang, W. Zhou, Z. Xiong, J. Chen, T.
Zhang and P. Chen, Energy Environ. Sci., 2012, 5, 5686-5689.
R. Moury, G. Moussa, U. B. Demirci, J. Hannauer, S. Bernard,
E. Petit, A. V. D. Lee and P. Miele, Phys. Chem. Chem. Phys.,
ϧ
,
2
4
4
4
4
4
4
2012, 14, 1768-1777.
2
1
0 J. Hannauer, O. Akdim, U. B. Demirci, C. Geantet, J. M.
Herrmann, P. Miele and Xu, Q. Energy Environ. Sci., 2011, 4,
,
5
3
355-3358.
6 L. He, B. Liang, L. Li, X. Yang, Y. Huang, A. Wang, X. Wang and
T. Zhang, ACS Catal., 2015, 5, 1623-1628.
7 Z. Zhang, Y. Wang, X. Chen and Z.H. Lu, J. Power Sources,
1
1
1
1
1
1
1
1 D. Clémençon, J. F. Petit, U. B. Demirci, Q. Xu and P. Miele, J.
Power Sources, 2014, 260, 77-81.
2
Ϧ
.
Ϧ
akany
Int. J. Hydrogen Energy, 2012, 37, 9722-9729.
ǹ
ld
ǹ
r m, U. B. Demirci, T. Şener, Q. Xu and P. Miele,
ǹ
2
015, 291, 14-19.
8 Y. Yang, Z.H. Lu, Y. Hu, Z. Zhang, W. Shi, X. Chen and T. Wang,
RSC Adv., 2014, 4, 13749-13752.
9 N. I. Kovtyukhova, P. J. Ollivier, B. R. Martin, T. E. Mallouk, S.
A. Chizhik, E. V. Buzaneva and A. D. Gorchinskiy, Chem.
Mater., 1999, 11, 771-778.
3 J. Thomas, M. Klahn, A. Spannenberg, T. Beweries, Dalton
Trans., 2013, 42, 14668-14672.
4 C. Li, Y. Dou, J. Liu, Y. Chen, S. He, M. Wei, D. G. Evans and X.
Duan, Chem. Commun., 2013, 49, 9992-9994.
5 S. Karahan, M. Zahmakǹran and S. Özkar, Int. J. Hydrogen
5
5
5
5
5
0 Z. Zhang, Z. H. Lu and X. Chen, ACS Sustainable Chem. Eng.,
Energy, 2011, 36, 4958-4966.
6 D. Özhava, N. Z. Kiliçaslan, S. Özkar, Appl. Catal. B: Environ.,
2
015, 3, 1255-1261.
1 Q. Yao, Z. H. Lu, Z. Zhang, X. Chen and Y. Lan, Sci. Rep., 2014
, 7597; DOI: 10.1038/srepo7597.
2 J. Liu, W. Tang, T. Shen, Z. Zhao, H. Feng, F. Cui, RSC Adv.,
014, 4, 30624-30629.
,
2015, 162, 573-582.
4
7 J. Wang, L. Wang, Y. Wen, L. Gu and Y. Zhang, Adv. Energy
Mater., 10.1002/aenm.201401879.
2
1
1
8 J. K. Sun, Q. Xu, ChemCatChem, 2015, 7, 526-531.
9 J. M. Yan, Z. L. Wang, H. L. Wang and Q. Jiang, J. Mater.
Chem., 2012, 22, 10990-10993.
3 J. Wang, X. B. Zhang, Z. L. Wang, L.M. Wang, Y. Zhang, Energy
Environ. Sci., 2012, 5, 6885-6888.
4 J. P. Rourke, P. A. Pandey, J. J. Moore, M. Bates, I. A. Kinloch,
2
2
2
2
2
2
0 H. L. Wang, J. M. Yan, S. J. Li, X. W Zhang and Q. Jiang, J.
Mater. Chem. A, 2015, 3, 121-124.
1 L. He, Y. Huang, A. Wang, X. Wang, X. Chen, J. J. Delgado and
T. Zhang, Angew. Chem. Int. Ed., 2012, 51, 6191-6194.
2 L. He, Y. Huang, A. Wang, Y. Liu, X. Liu, X. Chen, J. J. Delgado,
X. Wang and T. Zhang, J. Catal., 2013, 298, 1-9.
R. J. Young and N. R. Wilson, Angew. Chem. Int. Ed., 2011
23, 3231-3235.
5 D. X. Yang, A. Velamakanni, G. Bozoklu, S. Park, M. Stoller, R.
D. Piner, S. Stankovich, I. Jung and D. A. Field, Carbon, 2009
7, 145-152.
,
1
5
5
,
4
6 S. Stankovich, D. A. Dikin, R. D. Piner, K. A. Kohlhaas, A.
Kleinhammes, Y. Y. Jia, Y. Wu, S. T. Nguyen and R. S. Ruoff,
Carbon, 2007, 45, 1558-1565.
3 F. Yang, Y. Z. Li, W. Chu, C. Li, D. G. Tong, Catal. Sci. Technol.,
2014, 4, 3168-3179.
4 S. K. Singh, A. K. Singh, K. Aranishi and Q. Xu, J. Am. Chem.
Soc., 2011, 133, 19638-19641.
5 J. Wang, Y. Li and Y. Zhang, Adv. Funct. Mater., 2014, 24,
5
5
5
6
7 X. Liu, K. Zhou, L. Wang, B. Wang and Y. Li, J. Am. Chem. Soc.,
009, 131, 3140-3141.
2
8 X. B. Zhang, J. M. Yan, S. Han, H. Shioyama, Q. Xu, J. Am.
Chem. Soc., 2009, 131, 2778-2779.
9 D. G. Tong, W. Chu, P. Wu, G. F. Gu, L. Zhang, J. Mater. Chem.
A, 2013, 1, 358-366.
7
073-7077.
2
2
6 A.K. Singh, Q. Xu, ChemCatChem, 2013, 5, 3000-3004.
7 B. Xia, N. Cao, H. Dai, J. Su, X. Wu, W. Luoa and G. Cheng,
ChemCatChem, 2014, 6, 2549-2552.
0 D. G. Tong, W. Chu, P. Wu, L. Zhang, RSC Adv., 2012,
376.
2, 2369-
2
2
3
8 Y. Jiang, Q. Kang, J. Zhang, H. B. Dai and P. Wang, J. Power
Sources, 2015, 273, 554-560.
9 S-II. O, J. M. Yan, H. L. Wang, Z. L. Wang and Q. Jiang, J.
Power Sources, 2014, 262, 386-390.
0 W. Gao, C. Li, H. Chen, M. Wu, S. He, M. Wei, D. G. Evans and
X. Duan, Green Chem., 2014, 16, 1560-1568.
2
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 9
Please do not adjust margins

Journal of Materials Chemistry A
Page 10 of 10
View Article Online
DOI: 10.1039/C5TA06197K
Graphical abstract
x
Amorphous CeO -doped Rh-Ni NPs grown on reduced graphene oxide nanosheets
have been used as highly efficient and recyclable catalysts for complete hydrogen
generation from aqueous solution of N H BH or N H .
2
4
3
2
4