Ag nanoparticle-decorated biscuit-like Bi24O31Cl10 hierarchical microstructure composed of ultrathin nanoflake with outstanding photocatalytic activity

Article abstract of DOI:10.1016/j.jallcom.2017.11.190

Fabrication of noble-metal nanoparticle decorated hierarchical heterostructure photocatalyst composed of ultrathin nanoflake can be considered as one of the most effective approach for enhancing the photocatalytic performance due to its unique micro-scale structure and functional combination. Therefore, we report the successful preparation of Ag nanoparticle-decorated biscuit-like Bi₂₄O₃₁Cl₁₀ hierarchical microstructure through a facile solution-phase synthesis route. Experiment indicated that the Bi₂₄O₃₁Cl₁₀ product was comprised of ultrathin nanoflake with thickness of 5–10 nm. After introducing Ag nanoparticle, the as-obtained Ag-Bi₂₄O₃₁Cl₁₀ nanocomposite exhibited improved photocatalytic performance for the decolorization of rhodamine B in comparison to pure Bi₂₄O₃₁Cl₁₀ sample. The amount of Ag in the heterostructure photocatalyst significantly influenced the photocatalytic efficiency, and 4 wt% Ag exhibited the best photocatalytic performance. In addition, an enhanced mechanism of photodegradation activity over Ag nanoparticle-decorated biscuit-like Bi₂₄O₃₁Cl₁₀ hierarchical microstructure was proposed.

Full text of DOI:10.1016/j.jallcom.2017.11.190

Journal of Alloys and Compounds 735 (2018) 660e667
Contents lists available at ScienceDirect
Journal of Alloys and Compounds
journal homepage: http://www.elsevier.com/locate/jalcom
Ag nanoparticle-decorated biscuit-like Bi O Cl hierarchical
24 31 10
microstructure composed of ultrathin nanoflake with outstanding
photocatalytic activity
a
a
,
c
,
*
b
a
a, **
Jian Song , Lei Zhang
, Jian Yang , Jin-Song Hu , Xin-Hua Huang
a
School of Materials Science and Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001, PR China
South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou 510655, PR China
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China
b
c
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 26 April 2017
Received in revised form
Fabrication of noble-metal nanoparticle decorated hierarchical heterostructure photocatalyst composed
of ultrathin nanoflake can be considered as one of the most effective approach for enhancing the pho-
tocatalytic performance due to its unique micro-scale structure and functional combination. Therefore,
4
August 2017
we report the successful preparation of Ag nanoparticle-decorated biscuit-like Bi24
microstructure through a facile solution-phase synthesis route. Experiment indicated that the Bi24
product was comprised of ultrathin nanoflake with thickness of 5e10 nm. After introducing Ag nano-
particle, the as-obtained Ag-Bi24 31Cl10 nanocomposite exhibited improved photocatalytic performance
for the decolorization of rhodamine B in comparison to pure Bi24 31Cl10 sample. The amount of Ag in the
O31Cl10 hierarchical
Accepted 15 November 2017
Available online 16 November 2017
O
31Cl10
O
Keywords:
Ag-Bi24O31Cl10 heterostructure
photocatalyst
Solution-phase synthesis
Hierarchical structure
Ultrathin nanoflake
O
heterostructure photocatalyst significantly influenced the photocatalytic efficiency, and 4 wt% Ag
exhibited the best photocatalytic performance. In addition, an enhanced mechanism of photo-
degradation activity over Ag nanoparticle-decorated biscuit-like Bi24
O
31Cl10 hierarchical microstructure
was proposed.
©
2017 Elsevier B.V. All rights reserved.
1
. Introduction
As an important member of oxygen-enriched bismuth oxy-
halides family, Bi24 31Cl10 has aroused widespread concerns due to
the following characteristics [14]. (1) The unique crystal structure
of Bi24 31Cl10 can produce a strong internal electric field, helping to
efficient separation of photo-induced charge [15]. (2) Bi24
has a smaller bandgap than BiOCl, which means that it can absorb
more visible light [16]. (3) Bi24 31Cl10-based photocatalysts possess
high chemical and optical stability [17]. For example, Jin and co-
workers prepared a flaky Bi24 31Cl10 photocatalyst with a width of
m and a thickness of 10e30 nm by hydrothermal synthesis [18].
Cui et al. synthesized Bi24 31Cl10 hollow spherical structure with
excellent photocatalytic activity [19]. Unfortunately, the current
studies show that Bi24 31Cl10-based photocatalysts exhibit only
O
Since this great discovery of water decomposition over the TiO
2
electrode, photocatalytic technology has always attracted intense
research interest owing to its potential application in the contam-
inants elimination, energy regeneration and so on [1e3]. Over the
past few decades, TiO
field of photocatalysis due to its unique advantages such as
chemical stability, non-toxicity, low cost and photoactivity [4e6].
O
O
31Cl10
2
has gradually become a super star in the
O
O
However, the biggest drawback of TiO
bandgap, which means that it can only utilize the ultraviolet light
accounting for 5% of solar energy), resulting in a great waste of
2
is its relative larger
5 m
O
(
solar energy [7e10]. Therefore, taking into account the maximum
utilization of solar energy, it is urgent to exploit novel visible-light
photocatalysts with outstanding activity and stability [11e13].
O
limited photocatalytic performance. Therefore, subsequent struc-
tural modifications and functional assignments for this kind of
photocatalyst are unavoidable [20].
Generally, fabrication of hierarchical structure composed of ul-
trathin nanoflake has been proved as an effectual approach to
improve the photocatalytic efficiency [21e23]. Usually, this unique
micro-scale structure exhibits the following advantages: (1) fast
migration and separation of photo-generated charge; (2) anti-
*
Corresponding author. School of Materials Science and Engineering, Anhui
University of Science and Technology, Huainan, Anhui 232001, PR China.
** Corresponding author.
E-mail addresses: yutian1224@126.com (L. Zhang), hxh0317@hotmail.com
(
X.-H. Huang).
https://doi.org/10.1016/j.jallcom.2017.11.190
925-8388/© 2017 Elsevier B.V. All rights reserved.
0

J. Song et al. / Journal of Alloys and Compounds 735 (2018) 660e667
661
facilitates the interfacial charge migration derived from the well
known “schottky barriers” at the heterogeneous interface, leading
to the improved photocatalytic performance [11,31e33]. Therefore,
we believe that the integration of the two characteristics
mentioned above (hierarchical microstructure composed of ultra-
thin nanoflake and noble metal nanoparticle modification tech-
nology) is able to bring great improvement on the photocatalytic
activity. However, report about Ag nanoparticle decorated
Bi24O31Cl10 hierarchical microstructure composed of ultrathin
nanoflake is still relatively uncommon up to now.
Herein, we report the successful preparation of Ag nanoparticle-
decorated biscuit-like Bi24O31Cl10 hierarchical microstructure
through a simple and easy solution-phase synthesis approach. The
phase, morphology, optical absorption property as well as photo-
catalytic ability and stability were systematically investigated.
Benefiting from the unique micro-scale structure (hierarchical
microstructure composed of ultrathin nanoflake) and the “schottky
barriers” at the heterogeneous interface, the as-prepared Ag-
Bi24O31Cl10 heterostructure photocatalyst exhibited outstanding
photocatalytic performance and stability. In addition, the reason for
the improvement of photodegradation activity was also proposed.
Fig. 1. XRD pattern of biscuit-like Bi24O31Cl10 hierarchical microstructure (S1).
aggregation behaviour; (3) porous structure and high surface area
24e26]. However, if the separated photo-generated electrons
2. Experimental section
[
cannot be quickly exported, the recombination of electron and hole
pairs is inescapable [27e29]. Modification with noble metals on to
the surface of semiconductor photocatalysts has been demon-
strated as an effective route to solve this knotty issue [30]. The
noble metal nanoparticle usually acts as a sink for electrons, which
The detailed experimental processes, characterization methods
and photocatalytic measurements of pure Bi24O31Cl10 (S1) and
three Ag nanoparticle-decorated Bi24 31Cl10 photocatalysts with
O
different loading amounts (2 wt%: S2; 4 wt %: S3 and 6 wt%: S4)
could be found in the Supplementary Content.
Fig. 2. SEM images (aed) of biscuit-like Bi24O31Cl10 hierarchical microstructure (S1).

662
J. Song et al. / Journal of Alloys and Compounds 735 (2018) 660e667
3
. Results and discussion
the last three elements can be the result of Bi24O31Cl10. As illus-
trated in Fig. 3b, Bi 4f spectrum of S1 can be deconvoluted into two
signals with binding energies of 159.1 (4f7/2) and 164.4 eV (4f5/2),
The phase, composition and morphology of the product were
characterized by powder X-ray diffraction (XRD), energy dispersive
spectrometry (EDS) and scanning electron microscopy (SEM). As
implying the typical trivalence source of Bi in the Bi24O31Cl10
sample [18]. High-resolution XPS spectrum of Cl 2p in Fig. 3c ex-
hibits two signals locating at 198.1 and 199.7 eV, which may be
depicted in Fig. 1, peaks appearing in the original Bi24
line with the standard card (JCPDS card No. 75-0887), indicating the
successful preparation of pure Bi24 31Cl10. No other peaks attrib-
O31Cl10 are in
considered as the feature of the Cl species in Bi24O31Cl10 [19]. O 1s
O
spectrum can be divided into two different signals (Fig. 3d). Peak
with binding energies of 530.1 eV corresponds to the lattice oxygen
while another signal locating at 531.2 eV can be the result of surface
hydroxyl existed in the sample [36e38]. For the Ag-Bi24O31Cl10
sample (S3), there is no observable change in the peak positions of
Cl, Bi and O, implying that the introduction of Ag nanoparticles
uted to any impurities can be observed. To clarify the elemental
composition of the sample, EDS was introduced. As shown in
Fig. S1a (See Supplementary Content), four elements including C, O,
Cl and Bi can be easily found, which is in keeping with the XRD
result. The existence of the foreign C element can be explained by
the absorbed CO
2
from the atmosphere on the sample [34].
hardly changes the crystal structure of Bi24O31Cl10 matrix.
Fig. 2aeb shows the SEM images of the biscuit-like Bi24
O31Cl10
Furthermore, the Ag 3d XPS spectrum of S3 was also recorded. Two
hierarchical microstructure (S1), which reveals that the product
adopts a biscuit-like morphology with few micrometers in lengths
and several hundred nanometers in thicknesses. SEM images
recorded at high magnification clearly show that such biscuit-like
microstructure consists of randomly arranged ultrathin nano-
flakes (Fig. 2ced). These sheet-like building blocks are connected to
each other, leading to the formation of hierarchical porous struc-
ture. The thickness of the sheet-like building block is calculated to
be less than 10 nm.
peaks are identified at 374.1 and 368.1 eV, implying the presence of
metallic Ag in the Ag-Bi24O31Cl10 sample [39].
After introducing Ag nanoparticle, SEM images shown in
Fig. 4aec reveal that the product (S3) still maintains a biscuit-like
morphology. No significant size or morphology variation of
Bi24O
31Cl10 can be found after Ag loading, implying that photo-
reduction is a suitable method to deposit Ag nanoparticles on
31Cl10 without affecting its morphology. The corresponding
Bi24O
EDS spectrum illustrated in Fig. S1b (See Supplementary Content)
demonstrates that Ag peak also appears in addition to three peaks
X-ray photoelectron spectrum (XPS) was adopted to obtain the
composition and chemical state of the pure Bi24
O
31Cl10 (S1) and Ag
(Bi, O and Cl) derived from Bi24O31Cl10 matrix, which further con-
loaded Bi24 31Cl10 (S3) samples. Fig. 3a depicts the survey spectrum
O
firms the successful introduction of Ag nanoparticle. Moreover, due
to the low resolution of SEM analysis technique, transmission
electron microscopy (TEM) was also employed to understand the
of S1, from which four elements including C, Bi, O and Cl can be
easily found. The presence of C centered at 284.8 eV can be ascribed
to the adventitious hydrocarbon from the instrument itself, which
is usually employed as a reference [35]. The peaks corresponding to
fine structural information of the Ag-Bi24O31Cl10 heterostructure
photocatalyst. In Fig. 4d, one can find that the sheet-like structure
Fig. 3. XPS spectra of pure Bi24O31Cl10 (S1) and Ag-Bi24O31Cl10 sample (S3): (a) survey spectrum; (b) Bi 4f; (c) Cl 2p; (d) O 1s and (e) Ag 3d.

J. Song et al. / Journal of Alloys and Compounds 735 (2018) 660e667
663
Fig. 4. SEM (aec) and TEM images (def) of the Ag loaded Bi24O31Cl10 (S3).
can be the result of the Bi24
attributed to Ag nanoparticle. The thickness of the nanoflake is
calculated to be 5e10 nm. Interestingly, the high magnification TEM
O
31Cl10 while the nanoparticle can be
Bi24
O
31Cl10 microstructure can fully use the outer surfaces of Ag
31Cl10, which may enhance the
and interfaces between Ag and Bi24
separation efficiency of charge carriers as well as photocatalytic
performance.
O
image reveals that these Bi24O31Cl10 ultrathin nanoflakes are
formed by the interconnection of many small particles (Fig. 4e). As
displayed in Fig. 4f, the HRTEM image collected from the metal-
semiconductor interface exhibit two kinds of distinct lattice
fringes. One of the lattice fringes resulting from the semiconductor
region can be measured to be 0.329 nm, matching well to the (015)
The UVevis diffusion reflectance spectra were employed to
detect the photo-responsive performance of the samples. The
bandgap value of a semiconductor-based photocatalyst can be
determined using the following formula:
À
Á
n
plane of Bi24O31Cl10. Another one derived from metal region can be
a
h
n
¼ C h
n
ꢀ Eg
(1)
calculated to be 0.232 nm, which is the characteristic of (111) lattice
spacing in metallic Ag. The high-angle annular dark-field scanning
transmission electron microscopy and EDS mapping were used to
where
a
, h, n, C and E
g
are the absorption coefficient, Planck con-
stant, light frequency, a constant and band gap, respectively [40].
The variable n relies on the type of the transition in a semi-
conductor. In the case of direct band transition, it is assigned with
the value of 1/2 while 2 for indirect band transition [41]. The
further prove the successful construction of Ag-Bi24
erogeneous interface, which was consistent with TEM result
Fig. 5). Furthermore, it should be noted that the formation of Ag-
O31Cl10 het-
(

Fig. 5. The high-angle annular dark-field scanning transmission electron microscopy (a) and EDS mapping (bef) for the Ag loaded Bi24O31Cl10 (S3).
Fig. 6. The UVevis diffusion reflectance spectra of pure Bi24O31Cl10 (S1) and Ag loaded Bi24O31Cl10 samples with different Ag content (S2, S3 and S4).

J. Song et al. / Journal of Alloys and Compounds 735 (2018) 660e667
665
Fig. 7. (a) Photo-degradation performance of RhB solution as a function of irradiation time under exposure to UVevisible light and (b) kinetics of RhB decolorization in solutions.
bandgap energy of the above-mentioned four samples namely S1,
(S1-4) can be calculated to be 0.045, 0.060, 0.105, 0.053 minꢀ1. In
other words, S3 exhibits the highest photocatalytic ability, which is
about 2.3, 1.8 and 2 times higher than those of S1, S2 and S4,
respectively.
Capture experiments of active species were carried out to study
the photocatalytic mechanism of RhB (Fig. 8). The scavengers
S2, S3 and S4 are computed to be 2.79, 2.66, 2.61 and 2.55 eV by
2
taking the intercept of the line on abscissa [(
ah
n)
¼ 0] (Fig. 6).
Additionally, it should be noted that the introduction of Ag into the
surface of Bi24 31Cl10 can significantly increase the optical ab-
O
sorption capacity, which can be attributed to the surface plasmon
band of Ag nanoparticle, leading to the improvement of the pho-
tocatalytic performance [39]. Changes in optical absorption prop-
erties of the above four samples can also be confirmed by the colors
including isopropanol (IPA), sodium oxalate (SO, Na
benzoquinone (BQ) can be adopted to trap $OH, h and $O
2
C
2
O
4
) and
þ
ꢀ
2
,
respectively [45e47]. It can be seen that the effect of BQ on the
photocatalytic efficiency is very small. As for IPA, such influence
increases obviously, reducing this degradation efficiency from 95.8
to 81.0%. However, in the presence of SO, photocatalytic efficiency
decreases dramatically (from 95.8 to 1.5%). These experimental
results demonstrate that the degradation reaction of RhB can be
ascribed to the direct oxidation by photo-induced holes, implying
that the decolorization of RhB should follow the photocatalytic
mechanism rather than photosensitization mechanism, which is in
good agreement with previous reports [48]. Furthermore, photo-
catalytic decomposition experiment of phenol under exposure to
visible-light was carried out. The related experimental results can
be found in Fig. S2 (See Supplementary Content). One can find that
of pure Bi24
yellow to black, as shown in inserted images in Fig. 6.
The photocatalytic activities of the pure Bi24 31Cl10 (S1) and
three Ag loaded Bi24 31Cl10 samples (S2, S3 and S4) are investigated
O31Cl10 and Ag-Bi24O31Cl10 samples changing from
O
O
by the decolorization of RhB molecule under UVevisible light.
Blank experiment indicates that absorbance change of RhB solution
is negligible (Fig. 7a). As to pure Bi24O31Cl10, it also shows poor
photocatalytic activity. Only about 72.5% of RhB is decomposed
after 30 min. With the increasing loading amount of Ag, the pho-
tocatalytic activity increases first (S2: 82.09%; S3: 95.8%) and then
decreased (S4: 76.1%) and S3 possesses the highest photocatalytic
degradation efficiency. Fig. 7b shows the pseudofirst-order kinetics
data (lnC
0
/C ¼ kt) for the photodegradation of RhB over different
the as-prepared Ag-Bi24
exhibits excellent visible-light photocatalytic performance, which
O31Cl10 composite photocatalyst (S3) also
photocatalysts [16,42e44]. The reaction rates of four photocatalysts
Fig. 8. Photocatalytic degradation of RhB over the Ag-Bi24
O
31Cl10 sample (S3) with or
Fig. 9. Degradation efficiencies of RhB over the as-prepared Ag-Bi24O31Cl10 (S3) during
without quenchers.
4 catalytic runs.

666
J. Song et al. / Journal of Alloys and Compounds 735 (2018) 660e667
Bi24O
31Cl10 can directly oxidize RhB molecule, leading to an effi-
cient photocatalytic degradation reaction.
4. Conclusion
In summary, Ag nanoparticle-decorated biscuit-like Bi24O31Cl10
hierarchical microstructure were successfully constructed through
a facile solution-phase synthesis route. After introducing Ag
nanoparticle, the Ag-Bi24O31Cl10 hierarchical microstructure
exhibited enhanced photocatalytic performance. The amount of Ag
in the heterostructure photocatalyst significantly influenced the
photocatalytic efficiency, and 4 wt% Ag exhibited the best photo-
catalytic performance. The enhanced photocatalytic ability of the
Ag loaded Bi24O31Cl10 photocatalysts can be mainly attributed to
Fig. 10. Schematic diagram of the separation and transfer of photo-generated charges
over Ag nanoparticle-decorated biscuit-like Bi24
O
31Cl10 hierarchical microstructure.
the unique micro-scale structure (hierarchical microstructure
composed of ultrathin nanoflake) and the well-known “schottky
barriers".
further prove our above viewpoint.
In order to have a better understanding on the charge transfer,
we investigated the photocurrent responses of S1 and S3. As
depicted in Fig. S3 (See Supplementary Content), it can be found
Acknowledgements
This work was supported by National Natural Science Founda-
tion of China (No. 21501002 and 21671004), China Postdoctoral
Science Foundation Funded Project (2016M592031), Postdoctoral
Science Foundation Funded Project of Anhui Province (2016B107
and 2016B128), Open Fund of State Key Laboratory of Coordination
Chemistry (SKLCC1604) and CAS Key Lab of Novel Thin Film Solar
Cells (KF201602).
that Ag-Bi24O31Cl10 composite photocatalyst (S3) possesses higher
photocurrent response than pure Bi24O31Cl10 (S1), indicating a
more effective separation of photo-generated charges and faster
charges transfer [49e51]. Besides, the photocatalytic stability of Ag-
Bi24O31Cl10 composite photocatalyst (S3) was further studied by the
cyclic experiments due to the importance of lifetime of a photo-
catalyst for its practical application. The experiments were per-
formed under the identical condition. After the completion of each
experiment, the photocatalyst could be quickly collected from the
Appendix A. Supplementary data
ꢁ
dye solution, then washed and dried at 50 C for 5 h, finally applied
Supplementary data related to this article can be found at
https://doi.org/10.1016/j.jallcom.2017.11.190.
in the next run. As displayed in Fig. 9 and Figs. S4eS5 (See Sup-
plementary Content), it is clear that the XPS peak positions of Ag, Bi,
O and Cl in the Ag-Bi24O31Cl10 composite photocatalyst hardly
change, indicating its excellent stability and long lifetime.
Four reasons can explain the excellent photocatalytic property
References
[
1] C.H. An, S.T. Wang, Y.G. Sun, Q.H. Zhang, J. Zhang, C.Y. Wang, J.Y. Fang, Plas-
monic silver incorporated silver halides for efficient photocatalysis, J. Mater.
Chem. A 4 (2016) 4336e4352.
of Ag nanoparticle-decorated biscuit-like Bi24O31Cl10 hierarchical
microstructure. Firstly, the ultrathin geometry of the sheet-like
building units is helpful for the fast transfer and separation of
photo-induced charges and lead to a high-efficiency photocatalytic
reaction [52e55]. Secondly, the existence of the well-known “in-
[2] Y. Zhong, X.H. Xia, F. Shi, J.Y. Zhan, J.P. Tu, H.J. Fan, Transition metal carbides
and nitrides in energy storage and conversion, Adv. Sci. 3 (2016) 1500286.
[3] Y.Q. Cui, Q.L. Ma, X.Y. Deng, Q. Meng, X.W. Cheng, M.Z. Xie, X.L. Li, Q.F. Cheng,
H.L. Liu, Fabrication of Ag-Ag O/reduced TiO nanophotocatalyst and its
2
2
enhanced visible light driven photocatalytic performance for degradation of
diclofenac solution, Appl. Catal. B Environ. 206 (2017) 136e145.
[4] L.G. Devi, R. Kavitha, A review on plasmonic metal-TiO2 composite for gen-
eration, trapping, storing and dynamic vectorial transfer of photogenerated
electrons across the Schottky junction in a photocatalytic system, Appl. Surf.
Sci. 360 (2016) 601e622.
[5] H.J. Li, W.G. Tu, Y. Zhou, Z.G. Zou, Z-Scheme Photocatalytic systems for pro-
moting photocatalytic performance: recent progress and future challenges,
Adv. Sci. 3 (2016) 1500389.
ternal electric field” in the crystal structure of Bi24O31Cl10 sample
also plays a positive role for the improvement of photocatalytic
ability [56]. Thirdly, the hierarchical structure possesses superior
anti-aggregation behaviour, which contributes to maintain the high
active surface area and photocatalytic ability [57e60]. Finally,
although pure Bi24
specific surface area than Ag loaded Bi24
O
31Cl10 sample (S1) possess slightly higher
31Cl10 (S2, S3, S4, Fig. S6,
O
[6] H.L. Li, Y. Gao, X.Y. Wu, P.H. Lee, K.M. Shih, Fabrication of heterostructured g-
See Supplementary Content), the presence of Ag nanoparticle may
act as electron sink and thus facilitates the charge separation and
transfer in Ag-Bi24O31Cl10 heterogeneous interface, leading to the
improved photocatalytic performance [61e63]. In addition, it is also
found that moderate Ag can trap and transfer the photo-excited
electron, thus reducing the recombination of the electron-hole
pairs, which may explain the highest catalytic activity of S3 [39].
Based on the above experimental analysis and discussion, a
possible charge separation and transfer mechanism is proposed, as
3
C N
4
/Ag-TiO hybrid photocatalyst with enhanced performance in photo-
2
2
catalytic conversion of CO under simulated sunlight irradiation, Appl. Surf.
Sci. 402 (2017) 198e207.
[
7] S. Linic, P. Christopher, H.L. Xin, A. Marimuthu, Catalytic and photocatalytic
transformations on metal nanoparticles with targeted geometric and plas-
monic properties, Acc. Chem. Res. 46 (2013) 1890e1899.
8] X.Q. Liu, J. Iocozzia, Y. Wang, X. Cui, Y.H. Chen, S.Q. Zhao, Z. Li, Z.Q. Lin, Noble
metal-metal oxide nanohybrids with tailored nanostructures for efficient solar
energy conversion, photocatalysis and environmental remediation, Energy
Environ. Sci. 10 (2017) 402e434.
[
[
9] M.C. Long, W.M. Cai, Advanced nanoarchitectures of silver/silver compound
composites for photochemical reactions, Nanoscale 6 (2014) 7730e7742.
displayed in Fig. 10. Under the irradiation of UV-light, Bi24O31Cl10
will be excited, leading to the formation of photo-generated elec-
trons and holes. Due to the presence of metallic Ag nanoparticles on
[
10] K. Mondal, A. Sharma, Recent advances in the synthesis and application of
photocatalytic metal-metal oxide core-shell nanoparticles for environmental
remediation and their recycling process, RSC Adv. 6 (2016) 83589e83612.
11] M. Pirhashemi, A. Habibi-Yangjeh, Ultrasonic-assisted preparation of plas-
[
the surface of Bi24O31Cl10 matrix, the new-produced electrons on
2 4
monic ZnO/Ag/Ag WO nanocomposites with high visible-light photocatalytic
the conduction band will be exported to the Ag nanoparticles. This
phenomenon can be ascribed to the well-known “schottky effect”,
thus achieving an efficient separation of photo-induced charges
performance for degradation of organic pollutants, J. Colloid Interface Sci. 491
(2017) 216e229.
12] P. Rai, S.M. Majhi, Y.T. Yu, J.H. Lee, Noble metal@metal oxide semiconductor
core@shell nano-architectures as a new platform for gas sensor applications,
RSC Adv. 5 (2015) 76229e76248.
[
[39]. As a consequence, the separated holes on the valence band of

J. Song et al. / Journal of Alloys and Compounds 735 (2018) 660e667
13] H.L. Wang, L.S. Zhang, Z.G. Chen, J.Q. Hu, S.J. Li, Z.H. Wang, J.S. Liu, X.C. Wang, [39] Z.Q. Li, X.S. Lin, L. Zhang, X.T. Chen, Z.L. Xue, Fast preparation of Bi
667
GeO
[
[
2
5
Semiconductor heterojunction photocatalysts: design, construction, and
photocatalytic performances, Chem. Soc. Rev. 43 (2014) 5234e5244.
nanoflakes via a microwave-hydrothermal process and enhanced photo-
catalytic activity after loading with Ag nanoparticles, Mater. Res. Bull. 47
(2012) 2422e2427.
14] A. Aliev, J. Olchowka, M. Colmont, E. Capoen, C. Wickleder, O. Mentre, New
[
PbBi
2
O
4
][Bi
2
O
2
]Cl
2
and [Pb
n
Bi10-n
O
13][Bi
2
O
2
]
n
Cl4þn series by association of
[40] L. Zhang, X.F. Cao, X.T. Chen, Z.L. Xue, BiOBr hierarchical microspheres:
microwave-assisted solvothermal synthesis, strong adsorption and excellent
photocatalytic properties, J. Colloid Interface Sci. 354 (2011) 630e636.
[41] J. Shang, W.C. Hao, X.J. Lv, T.M. Wang, X.L. Wang, Y. Du, S.X. Dou, T.F. Xie,
D.J. Wang, J.O. Wang, Bismuth oxybromide with reasonable photocatalytic
reduction activity under visible light, ACS Catal. 4 (2014) 954e961.
[42] X. Xiao, R.P. Hu, C. Liu, C.L. Xing, X.X. Zuo, J.M. Nan, L.S. Wang, Facile micro-
sizable subunits: relationship with arppe's compound Bi24O31Cl10 and lumi-
nescence properties, Inorg. Chem. 52 (2013) 8427e8435.
[
15] G. Chen, G.L. Fang, G.D. Tang, Photoluminescence and photocatalytic proper-
ties of BiOCl and Bi24 31Cl10 nanostructures synthesized by electrolytic
corrosion of metal Bi, Mater. Res. Bull. 48 (2013) 1256e1261.
16] F.T. Li, Q. Wang, X.J. Wang, B. Li, Y.J. Hao, R.H. Liu, D.S. Zhao, n-situ one-step
O
[
synthesis of novel BiOCl/Bi24
O31Cl10 heterojunctions via self-combustion of
wave synthesis of novel hierarchical Bi24O31Br10 nanoflakes with excellent
ionic liquid with enhanced visible-light photocatalytic activities, Appl. Catal. B
Environ. 150 (2014) 574e584.
visible light photocatalytic performance for the degradation of tetracycline
hydrochloride, Chem. Eng. J. 225 (2013) 790e797.
[
[
17] H. Deng, J.W. Wang, Q. Peng, X. Wang, Y.D. Li, Controlled hydrothermal syn-
thesis of bismuth oxyhalide nanobelts and nanotubes, Chem. Eur J. 11 (2005)
[43] J.W. Zhang, G. Cao, H.Y. Wang, P.Z. Feng, Z.S. Liu, Graphene-Bi24O31Br10
composites with tunable architectures for enhanced photocatalytic activity
and mechanism, Ceram. Int. 42 (2016) 11796e11804.
[44] K.L. Li, W.W. Lee, C.S. Lu, Y.M. Dai, S.Y. Chou, H.L. Chen, H.P. Lin, C.C. Chen,
6519e6524.
18] X.L. Jin, L.Q. Ye, H. Wang, Y.R. Su, H.Q. Xie, Z.G. Zhong, H. Zhang, Bismuth-rich
strategy induced photocatalytic molecular oxygen activation properties of
3 4 2
Synthesis of BiOBr, Bi O Br, and Bi12O17Br by controlled hydrothermal
bismuth oxyhalogen: the case of Bi24
O
31Cl10, Appl. Catal. B Environ. 165
method and their photocatalytic properties, J. Taiwan Inst. Chem. Eng 45
(
2015) 668e675.
(2014) 2688e2697.
[
[
[
19] P.Z. Cui, J.L. Wang, Z.M. Wang, J. Chen, X.R. Xing, L.Z. Wang, R.B. Yu, Bismuth
oxychloride hollow microspheres with high visible light photocatalytic ac-
tivity, Nano Res. 9 (2016) 593e601.
3 4 2 3
[45] W. Fa, P. Wang, B. Yue, F. Yang, D. Li, Z. Zheng, Ag PO /Ag CO p-n hetero-
junction composites with enhanced photocatalytic activity under visible light,
Chin. J. Catal. 36 (2015) 2186e2193.
20] X.Y. Liu, Y.G. Su, Q.H. Zhao, C.F. Du, Z.L. Liu, Constructing Bi24
O
31Cl10/BiOCl
[46] X.B. Zhang, L. Zhang, J.S. Hu, X.H. Huang, Facile hydrothermal synthesis and
improved photocatalytic activities of Zn2 doped Bi
þ
nanosheets, RSC
heterojunction via a simple thermal annealing route for achieving enhanced
photocatalytic activity and selectivity, Sci. Rep. 6 (2016) 28689.
21] W.H. Dong, F. Pan, Y.Y. Wang, S.N. Xiao, K. Wu, G.Q. Xu, W. Chen, Surfactant-
free synthesis of hierarchical niobic acid microflowers assembled from ul-
trathin nanosheets with efficient photoactivities, Appl. Surf. Sci. 392 (2017)
2
MoO
6
Adv. 6 (2016) 32349e32357.
[47] J.P. Zou, S.L. Luo, L.Z. Zhang, J. Ma, S.L. Lei, L.S. Zhang, X.B. Luo, Y. Luo, G.S. Zeng,
C.T. Au, One-pot solvothermal syntheses of ternary heterostructured TiO
Bi MoO 6.55 controllable in terms of composition, morphology
2
-
2
6
/Bi3.64Mo0.36O
5
14e522.
22] Q.F. Han, J.W. Pang, X. Wang, X.D. Wu, J.W. Zhu, Synthesis of unique flowerlike
Bi (OH)(NO ) hierarchical microstructures with high surface area and su-
and structure: materials of high visible-light driven photocatalytic activity,
Appl. Catal. B Environ. 140 (2013) 608e618.
[48] G.M. Liu, J.C. Zhao, Photocatalytic degradation of dye sulforhodamine B: a
comparative study of photocatalysis with photosensitization, New J. Chem. 24
(2000) 411e417.
[
[
[
[
[
[
[
2
O
2
3
perior photocatalytic performance, Chem. Eur J. 23 (2017) 3891e3897.
23] R.A. He, S.W. Cao, J.G. Yu, Recent advances in morphology control and surface
modification of Bi-based photocatalysts, Acta Phys. - Chim. Sin. 32 (2016)
[49] K.C. Hung, Y.H. Lai, T.W. Lin, Enhancement of photocatalytic hydrogen for-
mation under visible illumination by integrating plasmonic Au nanoparticles
2
841e2870.
24] X.Y. Li, C.Z. Zhu, Y. Song, D. Du, Y.H. Lin, Solvent co-mediated synthesis of
ultrathin BiOCl nanosheets with highly efficient visible-light photocatalytic
activity, RSC Adv. 7 (2017) 10235e10241.
3 2
with a strongly catalytic Ni S /carbon nanotube composite, Catal. Sci. Technol.
6 (2016) 4020e4026.
[50] S. Zargari, R. Rahimi, A. Ghaffarinejad, A. Morsali, Enhanced visible light
photocurrent response and photodegradation efficiency over TiO -graphene
25] Y. Ma, Y.L. Jia, L.N. Wang, M. Yang, Y.P. Bi, Y.X. Qi, Hierarchical nanosheet-
2
based Bi
2
MoO
6
nanotubes with remarkably improved electrochemical per-
nanocomposite pillared with tin porphyrin, J. Colloid Interface Sci. 466 (2016)
310e321.
[51] L. Zheng, S. Han, H. Liu, P. Yu, X. Fang, Hierarchical MoS nanosheet@TiO
2 2
formance, J. Power Sources 331 (2016) 481e486.
26] P.F. Xia, B.C. Zhu, J.G. Yu, S.W. Cao, M. Jaroniec, Ultra-thin nanosheet assem-
blies of graphitic carbon nitride for enhanced photocatalytic CO
J. Mater. Chem. A 5 (2017) 3230e3238.
2
reduction,
nanotube array composites with enhanced photocatalytic and photocurrent
performances, Small 12 (2016) 1527e1536.
27] Z.S. Liu, J.N. Niu, P.Z. Feng, Y.B. Zhu, Solvothermal synthesis of Bi24
O
31Cl
x
Br10-x
[52] J. Song, L. Zhang, J. Yang, X.H. Huang, J.S. Hu, Facile hydrothermal synthesis of
3þ
solid solutions with enhanced visible light photocatalytic property, Ceram. Int.
1 (2015) 4608e4615.
Fe
doped Bi
2 2 9
Mo O ultrathin nanosheet with improved photocatalytic
4
performance, Ceram. Int. 43 (2017) 9214e9219.
28] M.F. Lu, A. Aliev, J. Olchowka, M. Colmont, M. Huve, C. Wickleder, O. Mentre,
Multidimensional open-frameworks: combinations of one-dimensional
channels and two-dimensional layers in novel Bi/M oxo-chlorides, Inorg.
Chem. 53 (2014) 528e536.
[53] X. She, L. Liu, H. Ji, Z. Mo, Y. Li, L. Huang, D. Du, H. Xu, H. Li, Template-free
synthesis of 2D porous ultrathin nonmetal-doped g-C
3 4
N nanosheets with
highly efficient photocatalytic H evolution from water under visible light,
2
Appl. Catal. B Environ. 187 (2016) 144e153.
[
[
[
29] L. Wang, J. Shang, W.C. Hao, S.Q. Jiang, S.H. Huang, T.M. Wang, Z.Q. Sun, Y. Du,
[54] J. Xia, M. Ji, J. Di, B. Wang, S. Yin, Q. Zhang, M. He, H. Li, Construction of ul-
S.X. Dou, T.F. Xie, D.J. Wang, J. Wang, A dye-sensitized visible light photo-
3 4 4 5 2
trathin C N /Bi O I layered nanojunctions via ionic liquid with enhanced
photocatalytic performance and mechanism insight, Appl. Catal. B Environ.
191 (2016) 235e245.
catalyst-Bi24
30] J.Q. Li, J. Zhou, H.J. Hao, W.J. Li, Controlled synthesis of Fe
Ag-010BiVO heterostructures with enhanced photoelectrochemical activity
toward the dye degradation, Appl. Surf. Sci. 399 (2017) 1e9.
O31Cl10, Sci. Rep. 4 (2014) 7384.
2 3
O modified
4
[55] P. Xia, B. Zhu, J. Yu, S. Cao, M. Jaroniec, Ultra-thin nanosheet assemblies of
2
graphitic carbon nitride for enhanced photocatalytic CO reduction, J. Mater.
Chem. A 5 (2017) 3230e3238.
[56] J. Li, Y. Yu, L.Z. Zhang, Bismuth oxyhalide nanomaterials: layered structures
meet photocatalysis, Nanoscale 6 (2014) 8473e8488.
[57] W. Kim, E. Edri, H. Frei, Hierarchical inorganic assemblies for artificial
photosynthesis, Acc. Chem. Res. 49 (2016) 1634e1645.
31] S.B. Ning, H.X. Lin, Y.C. Tong, X.Y. Zhang, Q.Y. Lin, Y.Q. Zhang, J.L. Long,
X.X. Wang, Dual couples Bi metal depositing and Ag@AgI islanding on BiOI 3D
architectures for synergistic bactericidal mechanism of E-coli under visible
light, Appl. Catal. B Environ. 204 (2017) 1e10.
2
[32] L. Wang, C.B. Zhang, F. Gao, G. Mailhot, G. Pan, Algae decorated TiO /Ag hybrid
nanofiber membrane with enhanced photocatalytic activity for Cr(VI) removal
under visible light, Chem. Eng. J. 314 (2017) 622e630.
[58] P.S. Kumar, J. Sundaramurthy, S. Sundarrajan, V.J. Babu, G. Singh,
S.I. Allakhverdiev, S. Ramakrishna, Hierarchical electrospun nanofibers for
energy harvesting, production and environmental remediation, Energy Envi-
ron. Sci. 7 (2014) 3192e3222.
[59] X. Li, J.G. Yu, M. Jaroniec, Hierarchical photocatalysts, Chem. Soc. Rev. 45
(2016) 2603e2636.
[
33] S.F. Yang, C.G. Niu, D.W. Huang, H. Zhang, C. Lianga, G.M. Zeng, SrTiO
3
nanocubes decorated with Ag/AgCl nanoparticles as photocatalysts with
enhanced visible-light photocatalytic activity towards the degradation of
dyes, phenol and bisphenol A, Environ. Sci.: Nano 4 (2017) 585e595.
[
[
[
[
[
34] L. Zhang, X.F. Cao, Y.L. Ma, X.T. Chen, Z.L. Xue, Microwave-assisted solution-
[60] J. Song, L. Zhang, J. Yang, X.H. Huang, J.S. Hu, Hierarchical porous Bi24O31Br10
phase preparation and growth mechanism of FeMoO
4
hierarchical hollow
microarchitectures assembled by ultrathin nanosheets with strong adsorption
and excellent photocatalytic performances, Mater. Des. 123 (2017) 128e136.
[61] H. Yu, W. Chen, X. Wang, Y. Xu, J. Yu, Enhanced photocatalytic activity and
photoinduced stability of Ag-based photocatalysts: the synergistic action of
amorphous-Ti(IV) and Fe(III) cocatalysts, Appl. Catal. B Environ. 187 (2016)
163e170.
spheres, CrystEngComm 12 (2010) 207e210.
35] D. Liu, Y.H. Lv, M. Zhang, Y.F. Liu, Y.Y. Zhu, R.L. Zong, Y.F. Zhu, Defect-related
photoluminescence and photocatalytic properties of porous ZnO nanosheets,
J. Mater. Chem. A 2 (2014) 15377e15388.
36] J. Di, J.X. Xia, M.X. Ji, S. Yin, H.P. Li, H. Xu, Q. Zhang, H.M. Li, Controllable
synthesis of Bi
4
O
5
Br
2
ultrathin nanosheets for photocatalytic removal of cip-
[62] G.H. Tian, Y.J. Chen, H.L. Bao, X.Y. Meng, K. Pan, W. Zhou, C.G. Tian, J.Q. Wang,
rofloxacin and mechanism insight, J. Mater. Chem. A 3 (2015) 15108e15118.
H.G. Fu, Controlled synthesis of thorny anatase TiO
2
tubes for construction of
37] Z.S. Liu, J.N. Niu, P.Z. Feng, Y.W. Sui, Y.B. Zhu, One-pot synthesis of Bi24
Bi
2014) 43399e43405.
38] Y. Peng, P.P. Yu, Q.G. Chen, H.Y. Zhou, A.W. Xu, Facile fabrication of Bi12
Bi24
J. Phys. Chem. C 119 (2015) 13032e13040.
O
31Br10
/
Ag-AgBr/TiO composites as highly efficient simulated solar-light photo-
2
4
V
2
O
11 heterostructures and their photocatalytic properties, RSC Adv. 4
catalyst, J. Mater. Chem. 22 (2012) 2081e2088.
(
[63] G.H. Tian, Y.J. Chen, X.Y. Meng, J. Zhou, W. Zhou, K. Pan, C.G. Tian, Z.Y. Ren,
H.G. Fu, Hierarchical composite of Ag/AgBr nanoparticles supported on
O
17Br
2
/
O
31Br10 type II heterostructures with high visible photocatalytic activity,
2 6
Bi MoO hollow spheres for enhanced visible-light photocatalytic perfor-
mance, ChemPlusChem 78 (2013) 117e123.