Template-free synthesis and enhanced photocatalytic performance of uniform BiOCl flower-like microspheres

Article abstract of DOI:10.1166/jnn.2015.9043

Preparation of uniform BiOCl flower-like microspheres was facilely accomplished through a simple protocol involving regulation of pH value in aqueous with sodium hydroxide in the presence of n-propanol. The as-prepared samples were characterized by a collection of techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), and nitrogen adsorption-desorption isotherms. Based upon the SEM analyses, uniform microspheres could be formed with coexistence of some fragments of BiOCl nanosheets without n-propanol. The addition of appropriate amount of n-propanol was beneficial to provide BiOCl samples containing only flower-like microspheres, which were further subjected to the photocatalytic measurements towards Rhodamine B in aqueous under visible light irradiation and exhibited the best catalytic performance among all samples tested. In addition, the photocatalytic process was confirmed to undergo through a photosensitization pathway, in which superoxide radicals (?·O-₂-) played critical roles.

Full text of DOI:10.1166/jnn.2015.9043

Article
Journal of
Nanoscience and Nanotechnology
Vol. 15, 1421–1426, 2015
Copyright © 2015 American Scientific Publishers
All rights reserved
Printed in the United States of America
www.aspbs.com/jnn
Template-Free Synthesis and Enhanced
Photocatalytic Performance of Uniform
BiOCl Flower-Like Microspheres
1ꢀ∗
1
1
1
1
Fei Chang , Yunchao Xie , Juan Chen , Jieru Luo , Chenlu Li ,
2ꢀ∗
3
Xuefeng Hu , and Bin Xu
1School of Environment and Architecture, University of Shanghai for Science and Technology,
Shanghai 200093, P. R. China
Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of
Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, P. R. China
2
3
Inspection and Quarantine Technology Center, Hainan Entry-Exit Inspection and Quarantine Bureau,
Haikou, Hainan 570311, P. R. China
Preparation of uniform BiOCl flower-like microspheres was facilely accomplished through a sim-
ple protocol involving regulation of pH value in aqueous with sodium hydroxide in the presence
of n-propanol. The as-prepared samples were characterized by a collection of techniques, such
Delivered by Publishing Technology to: Deakin University Library
as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy
IP: 99.198.58.144 On: Thu, 22 Oct 2015 08:49:36
(
TEM), energy dispersive X-ray spectroscopy (EDX), UV-vis diffuse reflectance spectroscopy (UV-vis
Copyright: American Scientific Publishers
DRS), and nitrogen adsorption–desorption isotherms. Based upon the SEM analyses, uniform
microspheres could be formed with coexistence of some fragments of BiOCl nanosheets without
n-propanol. The addition of appropriate amount of n-propanol was beneficial to provide BiOCl sam-
ples containing only flower-like microspheres, which were further subjected to the photocatalytic
measurements towards Rhodamine B in aqueous under visible light irradiation and exhibited the
best catalytic performance among all samples tested. In addition, the photocatalytic process was
•
−
confirmed to undergo through a photosensitization pathway, in which superoxide radicals ( O ꢀ
2
played critical roles.
Keywords: BiOCl, Microspheres, n-Propanol, Photocatalytic, Rhodamine B.
1
. INTRODUCTION
BiOCl is regarded as an effective catalyst that is in some
Semiconductor-based photocatalysis is a promising and
suitable technique towards environmental remediation
since it is capable of complete remove of organic
pollutants under mild conditions.
photocatalyts researched, bismuth oxychloride (BiOCl),
belonging to the V–VI–VII main group, has recently
cases more powerful than anatase TiO
organic pollutants.
2
over degrading
4
Hierarchical nanostructured BiOCl with controllable
sizes and morphologies is desired for the purpose of
1
–3
Among numerous
6
ꢀ8
enhancing photocatalytic performance.
dimensional (2D)
Hereby, two
9
–11
and three dimensional (3D)12–14
4
–6
attracted growing attention. It crystallizes in a tetrag-
onal matlockite structure consisting of [Bi O ] slabs
BiOCl nanostructures have been prepared through a vari-
ety of synthetic protocols. 3D hierarchical nanostructures
have the advantages of both microstructure and nano-
structure, such as the high crystallinity, high surface-to-
volume ratio, strong light-harvesting ability, and abundant
electronic transport paths, ensuring the improvement of
2
+
2
2
interleaved with double chloride anions layers, which
is favorable for an efficient separation of photoinduced
electron–hole pairs. In addition, BiOCl is an indirect-
band-gap semiconductor, featuring slow recombination
rate of electron–hole pairs. With both merits in structure,
7
ꢀ8
1
5ꢀ16
photocatalytic capability.
Zhang et al. synthesized
BiOCl microflowers and hollow microspheres exhibiting
excellent photocatalytic degradation capability over dye
∗
Authors to whom correspondence should be addressed.
J. Nanosci. Nanotechnol. 2015, Vol. 15, No. 2
1533-4880/2015/15/1421/006
doi:10.1166/jnn.2015.9043
1421

Template-Free Synthesis and Enhanced Photocatalytic Performance of Uniform BiOCl Flower-Like Microspheres
Chang et al.
Rhodamine B (RhB).12 Lei et al. reported that 3D hierar-
chical structured BiOCl showed higher photocatalytic effi-
were obtained on a JEOL JEM-2011 transmission elec-
tron microscope (TEM) equipped with Oxford Instru-
ments INCA energy-dispersive X-ray spectroscope (EDX).
The optical property of prepared samples was measured
through UV-vis diffuse reflectance spectroscopy (UV-vis
DRS, Hitachi U-4100) by using BaSO4 as a refer-
ence. Nitrogen adsorption–desorption isotherms at 77 K
were performed on an ASAP 2010 volumetric adsorption
analyzer.
1
3
ciency towards methyl orange than 2D nanoplates. Zhu
et al. demonstrated that 3D BiOCl hierarchitectures were
beneficial for photocatalysis in comparison with BiOCl
nanofibers.1 Although well-defined hierarchical BiOCl
can be readily fabricated, high reaction temperature and
toxic/expensive organics are generally unavoidable during
the hydrothermal or solvothermal syntheses. As a result,
facile synthetic protocols without toxic/expensive organ-
ics under mild conditions are highly required to construct
BiOCl hierarchitectures.
7
2.3. Photocatalytic Performance Evaluation
RhB was selected as a probe pollutant to evaluate pho-
tocatalytic performance of as-synthesized samples in a
LIMX-VII apparatus by Bylabo Precision Instrument Co.
Ltd. (Xi’an, China). The visible light was supplied from a
In our previous work, uniform BiOCl flower-like micro-
spheres were synthesized through a polyvinyl alcohol-
assisted hydrothermal process and showed satisfactory
1
8
photocatalytic performance. To continue the research,
in this investigation we reported the facile construction
of uniform BiOCl flower-like microspheres through sim-
ple regulation of pH value with sodium hydroxide in
the presence of n-propanol at ambient temperature. The
BiOCl samples with uniform flower-like structures exhib-
ited enhanced photocatalytic performance against RhB in
aqueous through a photosensitization pathway, in which
400 W halogen lamp (Institute for Electric Light Sources,
China) through a 420 nm cutoff glass filter. The suspension
containing RhB aqueous (40 mg/L, 40 mL) and catalyst
(
10 mg) was magnetically stirred for 1 h in dark to ensure
an adsorption–desorption equilibrium. During irradiation,
mL aliquot was sampled at certain time intervals, diluted,
2
and centrifuged to remove any suspended catalyst particles
prior to analysis at 554 nm using a T6 UV-vis spectropho-
tometer (Beijing Purkinje General Instrument Co., Ltd.,
China). The total organic carbon concentration was mea-
sured by a TOC analyzer (AnalytikJena multi N/C 3100
•
−
superoxide radicals ( O ꢁ played critical roles.
2
2. EXPERIMENTAL DETAILS
2
0
TOC, Germany). 1.0 mM isopropanol (IPA) and benzo-
Delivered by Publishing Technology to: Deakin University Library
2
.1. Preparation of BiOCl Samples
IP: 99.198.58.144 On: Thu,q 2u 2i n Oo n ce t (2B0 Q1 )5 0w 8e: r4e 9 a: 3d 6d ed to the photocatalytic system to
All chemical reagents were analytically pure and used
5
•
Copyright: American S cc iae p nt ut i rf iec hP y ud br ol i sx hy le rr sa dicals ( OH) and superoxide radicals
directly for experiments without any purification. Uniform
BiOCl flower-like microspheres were prepared as follows.
In a typical synthesis, Bi(NO ꢁ · 5H O (3.0 g) was dis-
•
−
(
O ), respectively.
2
3
3
2
solved in a HCl aqueous (2 M, 25 mL) under vigorous
stir to provide a transparent solution. A mixture of dis-
tilled water (20 mL) and n-propanol (10 mL) was dropped
into the above solution, followed by careful addition of
NaOH aqueous (4 M, 20 mL). The resultant white suspen-
3. RESULTS AND DISCUSSION
.1. Crystalline
3
The crystallinity and phase purity of BiOCl samples pre-
pared with different n-propanol volumes were examined by
XRD patterns. As shown in Figure 1, all diffraction peaks
ꢀ
sion was allowed to stir at 20 C for 0.5 h and then age
at the same temperature for 6 h. After reaction, the pre-
cipitate was collected, washed with deionized water and
ꢀ
ethanol for several times, and dried at 80 C overnight to
give a target sample, denoted as BOC10. Other samples
were prepared under a similar protocol except the varia-
tion of n-propanol volumes and denoted as BOCx, where
x referred to the volumes of n-propanol involved. N-doped
TiO219 and reference BiOCl were also prepared and sub-
jected to photocatalytic measurements for comparison.
18
2
.2. Characterization
The powder X-ray diffraction (XRD) patterns were
recorded on a Bruker D8 Advance X-ray diffractome-
ter using a Cu Kꢂ radiation source (ꢃ = 1ꢄ05406 Å).
The general morphology of samples was observed by
Hitachi S-4800 FEG scanning electron microscope (SEM)
under a working voltage of 200 kV. Transmission elec-
tron microscopy and energy-dispersive X-ray spectroscopy
Figure 1. XRD patterns of the as-synthesized samples (a) BOC0;
(b) BOC5; (c) BOC10; (d) BOC20.
1
422
J. Nanosci. Nanotechnol. 15, 1421–1426, 2015

Chang et al.
Template-Free Synthesis and Enhanced Photocatalytic Performance of Uniform BiOCl Flower-Like Microspheres
can be unambiguously indexed to the tetragonal phase of
BiOCl on the basis of the standard card JCPDS 06-0249.
average diameter of nearly 1.5 ꢅm are entirely assem-
bled by numerous BiOCl nanosheets, clearly shown in
Figures 2(C) and (E). In the absence or presence of
unsuitable amount of n-propanol, flower-like microspheres
can even be produced with coexistence of some frag-
ments of BiOCl nanosheets, as seen the circles labeled in
Figures 2(A), (B), and (D). It is obvious that the addi-
tion of appropriate amount of n-propanol favored to pro-
mote the formation of flower-like microspheres through
combination and assembly of BiOCl nanosheets. From the
images, we regarded that 10 mL n-propanol were suit-
able to produce uniform microspheres. Less than 10 mL,
such as 0 or 5 mL, might be insufficient to exert the role
and beyond 10 mL, like 20 mL, might obstruct other than
combine BiOCl nanosheets. The surface chemical com-
position of sample BOC10 was also tested by EDX. It
reveals that the uniform BiOCl flower-like microspheres
consist of only three elements Bi, O and Cl (the C and Cu
signals come from the holey carbon films and the copper
2
1
No diffraction peaks of other impurities are observable,
revealing the high purity of as-synthesized samples. The
narrow and sharp peaks indicate that all as-prepared BiOCl
samples are well crystallized. Further observations find that
the intensity ratio of the (110) peak to the (012) peak of
as-synthesized samples around 1.5 (BOC20 around 0.9)
is obviously larger than the data 0.8 of the JCPDS card,
suggesting that the crystal structure of BiOCl had special
6
anisotropic growth along the (110) plane.
3
.2. Morphology and Microstructure
The sizes and micromorphologies of microspheres BOC10
and other BiOCl samples were characterized by SEM and
TEM, as displayed in Figure 2.
From the SEM image in Figure 2(C), the sample BOC10
contains regular and uniform flower-like microspheres
in morphology. These flower-like microspheres with an
Delivered by Publishing Technology to: Deakin University Library
IP: 99.198.58.144 On: Thu, 22 Oct 2015 08:49:36
Copyright: American Scientific Publishers
Figure 2. SEM images of (A) BOC0, (B) BOC5, (C) BOC10, (D) BOC 20, enlarged SEM image (E) and TEM image (F) of the BOC10 sample.
J. Nanosci. Nanotechnol. 15, 1421–1426, 2015
1423

Template-Free Synthesis and Enhanced Photocatalytic Performance of Uniform BiOCl Flower-Like Microspheres
Chang et al.
Table I. The BET, E , and k of BiOCl samples.
grid, respectively). The atomic ratio of Bi:O:Cl is approx-
imately 1:1:1, further confirming the pure phase of BiOCl
in sample BOC10.
g
n-propanol Temperature
2
2
ꢀ
2
−1
−1
Sample
(mL)
( C)
BET (m g ꢁ E (eV) k (min
ꢁ
g
Based upon the observation so far, we proposed a brief
BOC0
BOC5
BOC10
BOC20
Reference
BiOCl
0
5
10
20
/
20
20
20
20
/
27ꢄ8659
20ꢄ6436
34ꢄ3853
31ꢄ1271
0ꢄ5713
3.18
0.023
0.031
0.036
0.034
0.004
mechanism of BiOCl microspheres formation. Bi(NO ꢁ ·
3
3
3.11
3.33
3.22
3.30
5
H O dissolved into the concentrated HCl and isolated into
2
3+
Bi ions, which could be stablized under highly acidic
environment in the presence of n-propanol as cochelating
reagents. With the gradual decrease of acidity through the
3
+
addition of NaOH, Bi ions inclined to hydrolyze to form
BiOCl crystal nuclei, which continued to grow to BiOCl
nanosheets or nanoflakes, according to their structures fea-
tures. These BiOCl nanosheets or nanoflakes were then
entirely assembled to provide uniform flow-like micro-
spheres in the presence of sutiable amount of n-propanol,
BiOCl sample. The isotherms of as-prepared flower-like
microspheres can be categorized as type IV observed in
the P/P range of 0.5 to 1.0 and shapes of the hystere-
0
sis loop are of type H3 associated with aggregates of
nanosheets, giving rise to slitlike pores, which is consis-
tent well with the SEM results. The specific surface areas
of all BiOCl samples were listed in Table I. The sam-
ple BOC10 with uniform BiOCl flower-like microspheres
and slitlike pore nanostructures possessed the largest spe-
cific surface area among all BiOCl samples. As a result,
it could afford abundant reactive sites exposing to pollutant
molecules. Furthermore, the slitlike pore nanostructures
could effectively increase the light harvesting, owing to the
light multi-reflection between self-assembled nanosheets.
These features might be favorable for the photocatalytic
though the exact role of n-propanol was still unkonwn and
required for further investigation.23
3
.3. UV-Vis DRS Analysis
The optical property of as-synthesized BiOCl samples was
measured by UV-vis diffuse reflectance spectra, as shown
in Figure 3. The band gap energy of BiOCl samples could
2
be calculated from the equation ꢂhv = Aꢆhv−E ꢁ , where
g
ꢂ, v, E , and A are absorption coefficient, light frequency,
g
2
4ꢀ25
band gap energy, and a constant, respectively.
The
inset of Figure 3 shows the (ꢂhv) versus (hv) curves of
the as-synthesized samp lDe se l ai vn ed r er ed f eb r ye nPc ue b Bl i si Oh Ci n lg s Ta me cp hl en .ology to: Deakin University Library
1
/2
2
7
performance.
1
/2
By extrapolating the straight poI rPt i :o 9n 9 o. 1f 9 (8ꢂ . 5h v8 ). 14- 4t o O- ( hn v: )Thu, 22 Oct 2015 08:49:36
3.5. Photocatalytic Activities
Copyright: American Scientific Publishers
plot to the ꢂ = 0 point, the band gap of samples BOC0,
All BiOCl samples together with N-doped TiO2 were
exposed to photocatalytic degradation measurements of
RhB under visible light irradiation. Figure 5(A) showed
the temporal evolution of the adsorption spectra of the RhB
solution over BOC10 sample. The intensity of the absorp-
tion peak of RhB was observed to gradually decrease with
prolonging the irradiation time, accompanying a blue shift
of the main adsorption peak to lower wavelength, mainly
BOC5, BOC10, and BOC20 are calculated in Table I
and are about 3.18 eV, 3.11 eV, 3.33 eV, and 3.22 eV,
respectively, which are slightly smaller than the literature
2
6
reported value 3.4 eV.
3
.4. N Adsorption–Desorption Isotherms
2
Figure 4 showed the nitrogen adsorption–desorption
isotherms of as-prepared BiOCl samples and reference
Figure 3. UV-vis diffuse reflectance spectra of as-synthesized samples
Figure 4. Nitrogen adsorption–desorption isotherms of (a) BOC0;
(
a) BOC0; (b) BOC5; (c) BOC10; (d) BOC20; (e) reference BiOCl.
(b) BOC5; (c) BOC10; (d) BOC20; (e) reference BiOCl.
1
424
J. Nanosci. Nanotechnol. 15, 1421–1426, 2015

Chang et al.
Template-Free Synthesis and Enhanced Photocatalytic Performance of Uniform BiOCl Flower-Like Microspheres
Delivered by Publishing Technology to: Deakin University Library
IP: 99.198.58.144 On: Thu, 22 Oct 2015 08:49:36
Figure 5. (A) The temporal evolution of the absorbance spectra and photographic image of the RhB at given time intervals. (B) Photocatalytic
Copyright: American Scientific Publishers
activities of RhB over as-prepared BiOCl samples: (a) BOC0; (b) BOC5; (c) BOC10; (d) BOC20; (e) reference BiOCl; (f) N-doped TiO ; (g) Blank.
2
(
C) RhB and TOC removal rate during the photodegradation over BOC10 sample. (D) Plots of active species capturing for photocatalytic degradation
of RhB over BOC10 sample.
attributing to a step-by-step deethylation of RhB.28 Dur-
ing reaction, the color of the suspension changed gradually
from initial fuchsia red to light green–yellow after irradi-
ation for 120 min. In order to simplify the analysis, the
characteristic absorption peak at 554 nm was employed to
evaluate the photocatalytic degradation.
pore nanostructures assembled from nanosheets, which
could increase both the interfacial surface area between
catalysts and pollutant molecules and mass transfer of
reactants and products. Meanwhile, the slitlike pore nano-
structures between the nanosheets were able to enhance
light harvesting, which excited more pollutant molecules
to excited states and inject photoinduced electrons to the
conduction band of BiOCl, felicitating the photosensitiza-
tion process.
Direct photolysis of RhB under the same condition
2
9
could almost be negligible. Meanwhile, N-doped TiO2
showed quite low photocatalytic performance even with
the increasing irradiation time. Among all BiOCl samples,
the uniform flower-like microspheres BOC10 had the high-
est photodegration rate, which was about 9 times higher
than reference BiOCl sample, shown in Table I. About
In Figure 5(C), the variation of TOC was measured over
sample BOC10 to determine the complete mineralization
of RhB. The TOC decrease only 48% was gained after
120 min, much lower than the value over 99% obtained
by UV-vis absorption analysis, mainly owning to the com-
plicated mineralization of RhB and only the TOC in the
5
5% of RhB could be consumed after 30 min irradia-
tion and the residue could be completely removed after
20 min for sample BOC10. However, only 35% of RhB
3
0
1
solution counted.
was removed over reference BiOCl after 120 min, as seen
in Figure 5(B). Catalyzed degradation of oxalic acid was
also conducted and no concentration decrease was found
by TOC analysis, which revealed the degradation by syn-
thesized BiOCl samples were undergone in a photosen-
sitization manner. In addition, the remarkable variation
of the photocatalytic activities between reference BiOCl
and BOC10 sample was mainly attributed to the slitlike
Different active species capturing experiments were car-
ried out and exhibited in Figure 5(D). The degradation
efficiency of RhB kept identical after introduction of
•
IPA, indicating that OH was not the main reactive rad-
icals. However, the degradation of RhB over BiOCl was
almost inhibited when 1 mM BQ was added, suggesting
•
−
that O radicals were crucial to the photosensitization
2
process.
J. Nanosci. Nanotechnol. 15, 1421–1426, 2015
1425

Template-Free Synthesis and Enhanced Photocatalytic Performance of Uniform BiOCl Flower-Like Microspheres
Chang et al.
4
. CONCLUSIONS
9. J. M. Ma, X. D. Liu, J. B. Lian, X. C. Duan, and W. J. Zheng, Cryst.
Growth Des. 10, 2522 (2010).
0. J. Y. Xiong, G. Cheng, R. M. Wang, H. Yang, S. Q. Xiao, and
R. Chen, Sci. Adv. Mater. 5, 1024 (2013).
In summary, we have facilely constructed uniform BiOCl
flower-like microspheres through simple regulation of pH
value in aqueous with sodium hydroxide in the presence
of n-propanol. It was obvious that the appropriate amount
n-propanol was quite important to produce BiOCl sam-
ples containing only flower-like microspheres. Otherwise,
some fragments of BiOCl nanosheets were still coexisted.
The uniform BiOCl flower-like microspheres exhibited
enhanced photocatalytic performance against Rhodamine
B in aqueous, mainly attributing to the unique morpholo-
gies that ensured the increase of interfacial surface area,
mass transfer and light harvesting. The photocatalytic pro-
cess were undergone through a photosensitization pathway,
1
11. Y. Y. Li, J. P. Liu, J. Jiang, and J. G. Yu, Dalton Trans. 40, 6632
(2011).
12. K. Zhang, J. Liang, S. Wang, J. Liu, K. X. Ren, X. Zheng, H. Luo,
Y. J. Peng, X. Zou, X. Bo, J. H. Li, and X. B. Yu, Cryst. Growth
Des. 12, 793 (2011).
1
1
1
1
3. Y. Q. Lei, G. H. Wang, S. Y. Song, W. Q. Fan, and H. J. Zhang,
CrystEngComm. 11, 1857 (2009).
4. J. M. Song, C. J. Mao, H. L. Niu, Y. H. Shen, and S. Y. Zhang,
CrystEngComm. 12, 3875 (2010).
5. Y. Y. Li, J. P. Liu, X. T. Huang, and G. Y. Li, Cryst. Growth Des.
7, 1350 (2007).
6. L. Zhou, W. Z. Wang, H. L. Xu, S. M. Sun, and M. Shang, Chem.-
Euro. J. 15, 1776 (2009).
•
−
in which superoxide radicals ( O ) played critical roles.
2
17. L. P. Zhu, G. H. Liao, N. C. Bing, L. L. Wang, Y. Yang, and H. Y.
Xie, CrystEngComm. 12, 3791 (2010).
Acknowledgments: The authors are grateful to the
National Natural Science Foundation of China (Grant
numbers 21207089 and 41076040), the Innovation Pro-
gram of Shanghai Municipal Education Commission
18. Y. C. Xie, F. Chang, C. L. Li, J. Chen, J. R. Luo, L. Li, and X. F.
Hu, Clean-Soil, Air, Water doi:10.1002/clen.201300014.
19. T. T. Li, L. H. Zhao, Y. M. He, J. Cai, M. F. Luo, and J. J. Lin,
Appl. Catal. Bꢇ Environ. 129, 255 (2013).
20. P. F. Ji, J. L. Zhang, F. Chen, and M. Anpo, Appl. Catal. Bꢇ Environ.
(
Grant number 11YZ113), the project-sponsored by
SRF for ROCS, SEM, and 863 project (Grant number
013AA06A207-1) for financial support.
85, 148 (2009).
21. Z. Ling, W. Z. Wang, L. Zhou, M. Shang, and S. M. Sun, Appl.
Catal. Bꢇ Environ. 90, 458 (2009).
2
22. L. Chen, S. F. Yin, R. Huang, Y. Zhou, S. L. Luo, and C. T. Au,
Catal. Commun. 23, 54 (2012).
References and Notes
23. G. L. Chai, C. S. Lin, J. Wei, M. Y. Zhang, and W. D. Cheng, Phys.
Chem. Chem. Phys. 14, 835 (2012).
1
. A. Fujishima and K. Honda, Nature 238, 37 (1972).
2
4. L. S. Zhang, W. Z. Wang, L. Zhou, and H. L. Xu, Small 3, 1618
2. H. J. Zhang, G. H. Chen, and D. W. Bahnemann, J. Mater. Chem.
Delivered by Publishing Technology to: Deakin University Library
19, 5089 (2009).
(2007).
IP: 99.198.58.144 On: Thu, 22 Oct 2015 08:49:36
3. H. T. Li, X. D. He, Z. H. Kang, H. Huang, Y. Liu, J. L. Liu, S. Y.
25. S. J. Peng, L. L. Li, P. N. Zhu, Y. Z. Wu, M. Srinivasan, S. G.
Mhaisalkar, S. Ramakrishna, and Q. Y. Yan, Chem.-Asian J. 8, 258
(2013).
Copyright: American Scientific Publishers
Lian, C. H. A. Tsang, X. B. Yang, and S. T. Lee, Angew. Chem. Int.
Ed. 49, 4430 (2010).
4
5
6
7
8
. K. L. Zhang, C. M. Liu, F. Q. Huang, C. Zheng, and W. D. Wang,
Appl. Catal. Bꢇ Environ. 68, 125 (2006).
. J. F. Li, Y. C. Zhu, Y. Yan, B. J. Xi, K. B. Tang, and Y. T. Qian,
J. Nanosci. Nanotechnol. 12, 2068 (2012).
. J. X. Xia, J. Zhang, S. Yin, H. M. Li, H. Xu, L. Xu, and Q. Zhang,
J. Phys. Chem. Solids 74, 298 (2013).
. X. P. Lin, T. Huang, F. Q. Huang, W. D. Wang, and J. L. Shi, J. Phys.
Chem. B 110, 24629 (2006).
. Y. J. Liang, C. F. Guo, S. H. Cao, Y. Tian, and Q. Liu, J. Nanosci.
Nanotechnol. 13, 919 (2013).
26. Z. T. Deng, F. Q. Tang, and A. J. Muscat, Nanotechnology
19, 295705 (2008).
27. S. W. Liu, C. Li, J. G. Yu, and Q. J. Xiang, CrystEngComm. 13, 2533
(2011).
28. H. B. Fu, C. S. Pan, W. Q. Yao, and Y. F. Zhu, J. Phys. Chem. B
109, 22432 (2005).
29. J. X. Xia, S. Yin, H. M. Li, H. Xu, L. Xu, and Y. G. Xu, Dalton
Trans. 40, 5249 (2011).
30. W. Xiong, Q. D. Zhao, X. Y. Li, and D. K. Zhang, Catal. Commun.
16, 229 (2011).
Received: 9 June 2013. Accepted: 9 October 2013.
1
426
J. Nanosci. Nanotechnol. 15, 1421–1426, 2015