Photocatalyst Bi(OH)SO4 · H2O with High Photocatalytic Performance

Article abstract of DOI:10.1134/S0036024418100084

Abstract: In this work, Bi(OH)SO₄ · H₂O, a novel photocatalyst was prepared by a facile method. The sample was characterized by XRD, XPS, SEM, Mott-Schottky curve and ESR. The band gap of Bi(OH)SO₄ · H₂O is about 4.64 eV, and its CB and VB are estimated at –0.5 and 4.14 eV, respectively. Degradation of RhB and PhOH under UV light irradiation illustrates that the sample has good UV activity. The results of ESR spectra and tapping experiments indicate that the main active species in the photocatalytic reaction process are hydroxyl radicals, superoxide radicals and holes. A possible mechanism of catalytic degradation of organic pollutants was proposed. This semiconductor has a positive valence band and high oxidation capacity theoretically and it may have broad application in synthesizing highly efficient photocatalysts through doping other elements or creating heterojunctions.

Full text of DOI:10.1134/S0036024418100084

ISSN 0036-0244, Russian Journal of Physical Chemistry A, 2018, Vol. 92, No. 10, pp. 2075–2080. © Pleiades Publishing, Ltd., 2018.
PHOTOCHEMISTRY
AND MAGNETOCHEMISTRY
Photocatalyst Bi(OH)SO4 · H2O
with High Photocatalytic Performance1
Haojie Lua, Ruiting Wanga, Linghua Zhanga, Daimei Chena,*,
Qiang Haoa,**, Chao Mab, and Wenqing Yaob,***
aBeijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral
Materials, School of Materials Science and Technology, China University of Geosciences, Beijing, 100083 China
bDepartment of Chemistry, Tsinghua University, Beijing, 100084 PR China
*e-mail: chendaimei@cugb.edu.cn
**e-mail: haoqiang@cugb.edu.cn
***e-mail: yaowq@tsinghua.edu.cn
Received May 31, 2017
Abstract—In this work, Bi(OH)SO4 · H2O, a novel photocatalyst was prepared by a facile method. The sam-
ple was characterized by XRD, XPS, SEM, Mott-Schottky curve and ESR. The band gap of Bi(OH)SO4 ·
H2O is about 4.64 eV, and its CB and VB are estimated at –0.5 and 4.14 eV, respectively. Degradation of RhB
and PhOH under UV light irradiation illustrates that the sample has good UV activity. The results of ESR
spectra and tapping experiments indicate that the main active species in the photocatalytic reaction process
are hydroxyl radicals, superoxide radicals and holes. A possible mechanism of catalytic degradation of organic
pollutants was proposed. This semiconductor has a positive valence band and high oxidation capacity theo-
retically and it may have broad application in synthesizing highly efficient photocatalysts through doping
other elements or creating heterojunctions.
Keywords: Bi(OH)SO4 · H2O, photocatalyst, positive valence band
DOI: 10.1134/S0036024418100084
INTRODUCTION
the corresponding redox potential [15]. In the process
of photocatalytic reaction, the band structure is the
most important factor affecting the catalytic activity
[16–18]. Generally, raising the valence band of reduc-
ing the conduction band can both narrow the band gap
and extend spectral response range [19–21]. Creating
continuous stable valence band, which is more nega-
tive than the O 2p level, can well narrow the band gap.
One way is to introduce some nonmetal elements with
lower electronegativity such as sulfur or nitrogen [22–
25]. That is because their p orbital energy levels are
higher than the 2p orbit of oxygen, mixing with the
O 2p orbit or forming a lower valence band inde-
pendently, the band gap can be narrowed and the
spectral response range can be extended. Another way
is to introduce elements with a d10 electronic configu-
ration such as silver zinc [26–29].
Recently, more works about reduced valence band
and enhanced photocatalytic activity of semiconduc-
tors are reported. Zhang et al. prepared potassium
doped g-C3N4 using potassium iodide and dicyandi-
amide as precursors. The introduction of potassium
can reduce the valence band of g-C3N4 about 0.22 eV
[30]. Zhang et al. synthesized Bi-doped Ag3PO4 by an
ion exchange method and the valence band position
In recent years, photocatalytic technology has
attracted the interest of researchers due to the advan-
tages of low cost, high efficiency and non-pollution,
which is thought to have broad application prospect to
solve energy and environmental problems in the future
[1–4]. Under light irradiation, semiconductors can be
excited and produce electrons and holes, which can
form strong oxidizing species. Thus photocatalysts are
capable of effectively reducing H2O to H2 and com-
pletely mineralizing organic pollutants in water into
CO2 and H2O [5–10]. However, the low utilization
rate of solar energy and rapid recombination of photo-
generated charge carriers limited the applications of
photocatalytic technology for the industrial applica-
tion [11, 12]. Therefore, developing novel and highly
efficient photocatalysts is significant for the applica-
tion of photocatalytic technology.
The band structure of semiconductors is composed
of a valence band filled with electrons and an empty
conduction band [13, 14]. The electrons on the con-
duction band have reducibility, and the holes in the
valence band are oxidizing. Thus semiconductors have
1
The article is published in the original.
2075

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HAOJIE LU et al.
12000
(a)
(b)
10000
8000
6000
4000
2000
0
Bi
S
O
10 20 30 40 50 60 70 80 90
2θ, deg
Fig. 1. (a) The crystal structure of Bi(OH)SO · H O; (b) XRD pattern of Bi(OH)SO · H O.
4
2
4
2
was reduced [31]. Besides doping other elements,
using conjugated molecules to reduce valence band
positions is also an effective method. Bai et al. pre-
pared C60/C3N4 composite photocatalyst with
reduced valence band and enhanced photocatalytic.
Other conjugated carbon-based materials also have
Characterization
X-ray diffraction (XRD) patterns were recorded on a
Rigaku D/max-2400 X-ray diffractometer with CuKα
radiation. UV–Vis diffuse reflectance spectra (DRS)
were measured with a Hitachi U-3900 UV–Vis spec-
similar effects [32]. However, developing novel semi- trophotometer using BaSO4 as reference. A Bruker
conductor photocatalysts with intrinsic low valence
band and theoretical strong oxidation ability is rarely
reported.
300E electron paramagnetic resonance spectrometer
was used to measure ESR spectra; radical scavenger
5,5-dimethyl-1-pyrroline N-oxide (DMPO) was used
to determine the ESR signal of hydroxyl radical and
superoxide radical in methanol and water, respec-
tively. Scanning electron microscope (SEM) images of
the sample were obtained on a HITACHI SU-8010
instrument. The energy dispersive spectrometer
(EDS) images of the sample were obtained from an
Oxford X-max 50 electron energy spectrometer
mounted on the SEM. X-ray photoelectron spectra
(XPS) of the as prepared samples were obtained on a
PHI Quantera XPS microprobe.
In this work, a novel photocatalyst Bi(OH)SO4 ·
H2O with high oxidation ability theoretically is pre-
pared by a facile method. Compared with the common
Bi-based photocatalysts, it has a more positive valence
band, suggesting it might possess the stronger oxida-
tive ability and it may have broad application in syn-
thesizing highly efficient photocatalysts through dop-
ing other elements or creating heterojunctions.
EXPERIMENTAL
Photocatalytic activity test. The photocatalytic
activity of the sample was evaluated by the degradation
of Rhodamine B (RhB) and Phenol (PhOH) under
Ultraviolet (UV) light irradiation which was provided
by a 500 W mercury lamp without using cutoffs and
the average luminous intensity is 40 mW/cm2. Photo-
catalyst sample (50 mg) was uniformly dispersed in an
aqueous solution of RhB (50 mL, 5 ppm) and PhOH
(50 mL, 5 ppm), respectively. Before light irradiation,
the suspensions were magnetically stirred in the dark
for 30 min to ensure the absorption–desorption equi-
All chemicals used were of reagent grade and used
without further purification.
Synthesis of Bi(OH)SO4 · H2O
BiNO3 · 5H2O (2 g) was dried at 60°C for 2 h and
the obtained powder was transferred into a corundum
crucible. After that, the sample was heated to 600°C
within 150 min and kept at that temperature for 4 h.
The obtained yellow powder was Bi2O3. Bi2O3 (1 g) librium. Then Hg lamp turned on and 3 mL aliquots
were sampled at certain time intervals and filtered.
The concentration of RhB was analyzed by measuring
the maximum absorption wavelength (553 nm) using a
Hitachi U-3900 UV–Vis spectrophotometer. The
concentration of PhOH was measured by high-perfor-
mance liquid chromatography (HPLC) (Shimadzu
LC-20AT).
was added into 20 mL (ω) 98% H2SO4 and stirred for
12 h, during which process, the yellow suspension
gradually changed to white. Then the white suspen-
sion was poured into 200 mL deionized water with stir-
ring. After 8 h, white acicular crystals were obtained.
They were washed to neutral and dried at 60°C for
12 h.
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PHOTOCATALYST Bi(OH)SO4 · H2O WITH HIGH PHOTOCATALYTIC PERFORMANCE
C
2077
5 μm
5 μm
20 μm
(а)
(b)
S
(c)
Bi
O
5 μm
5 μm
5 μm
(d)
(e)
(f)
Fig. 2. Morphology and structure of the sample. SEM images of Bi(OH)SO · H O (a, b) and EDS elemental distributions of C,
4
2
O, S, and Bi are shown in (c–f), respectively.
RESULTS AND DISCUSSION
The chemical composition of the sample surface
can be detected by XPS [33, 34]. It can be seen from
the XPS spectra of Bi(OH)SO4 · H2O sample that
there are three elements of Bi, O, and S of the sample.
The test result matches the elemental composition of
the sample well.
Morphology and Structure
Figures 1a and 1b are crystal structure model and
XRD pattern of Bi(OH)SO4 · H2O sample, respectively.
The diffraction peaks of the sample in Fig. 1b can be
indexed to Bi(OH)SO4 · H2O (JCPDS = 057-0974). The
apparent diffraction peaks of other substances are not
found in Fig. 1b, indicating that the sample has a high
purity. According to the Fig. 1a and the standard card,
the Bi(OH)SO4 · H2O crystallizes in the monoclinic
space group P21/n with the parameters a = 6.0118 Å,
b = 13.3355 Å, c = 6.4854 Å. The Fig. 1b and the stan-
dard card show that the diffraction peaks at 17.32°,
20.84°, and 32.85° correspond to the crystal faces
(110), (120), and (131), respectively.
From Fig. 2a, Bi(OH)SO4 · H2O appears as a rod-
like structure under SEM. The X-ray energy dispersive
spectrometer (EDS) images of the four elements of C,
Bi, O, and S are shown in Figs. 2c–2f, respectively. C
is mainly from the conductive adhesive. It is easy to see
that the prepared sample is uniformly distributed by
three elements of Bi, O, and S.
Photocatalytic Activity
Figure
3 shows the degradation effect of
Bi(OH)SO4 · H2O on the RhB in aqueous solution
under UV irradiation. The content of RhB decreased
gradually with the increase of time. After 75 min, the
concentration of RhB in solution was 33.9% of the ini-
tial solution. The result shows that Bi(OH)SO4 · H2O
has good photocatalytic degradation activity for RhB.
0.9
0.7
1
0.5
To further study the UV activity of Bi(OH)SO4 ·
H2O, Bi(OH)SO · H2O was used to degrade PhOH
under UV irradiation. It can be concluded from the
Fig. 3 that the content of PhOH in solution is gradu-
ally mineralized over time. After 65 min, the content
of PhOH in the solution is reduced to 30.81% of the
initial solution, which further shows that Bi(OH)SO4 ·
H2O has good UV activity.
2
0.3
0
20
40
60
80
Time, min
Fig. 3. Time dependence of RhB (1) and PhOH (2) in pure
water under UV irradiation in the presence photocatalyst.
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HAOJIE LU et al.
Organic pollutants
e− e− e−
−0.50 eV
CB
VB
H2O
CO2
h+ h+ h+
4.14 eV
Scheme 1. A possible mechanism of Bi(OH)SO · H O degradation of organic pollutants under UV irradiation.
4
2
Mechanism for Photocatalytic Activity
During the experiment, N2 was used to remove O2 to
prevent the generation of superoxide radicals. IPA and
NaHCO3 could capture hydroxyl radicals and holes,
respectively. The photocatalytic degradation activity
of Bi(OH)SO4 · H2O obviously decreased after N2,
The UV–Vis diffuse reflectance spectra of
Bi(OH)SO4 · H2O sample can be informed that the
absorption edge of Bi(OH)SO4 · H2O is about
267.2 nm [35, 36]. The band gap of Bi(OH)SO4 · H2O
is 4.64 eV by extrapolating the straight line to the X axis
indicating that Bi(OH)SO4 · H2O can be excited by
UV light [37].
NaHCO3, and IPA were introduced. This proved that
the main active species in the process of degradation is
•
O•2− OH
,
, and holes.
In order to estimate the conduction band and
valence band of Bi(OH)SO4 · H2O sample, Mott–
Schottky test was conducted [38, 39]. The slope of the
straight line is greater than zero, so the Bi(OH)SO4 ·
H2O sample belongs to n-type semiconductor [40].
The flat band potential of Bi(OH)SO4 · H2O is –0.5 eV
[41–43], indicating that the conduction band poten-
tial is approximate –0.5 eV. As can be seen from the
above, the band gap is 4.64 eV, so the valence band
potential is 4.14 eV.
The mechanism of Bi(OH)SO4 · H2O photocata-
lyst degradation of organic pollutants might be under-
stood as follows (Scheme 1). Under sunlight irradia-
tion, Bi(OH)SO4 · H2O is excited to produce electrons
and holes:
Bi(OH)SO4 ⋅ H2O + hν
(1)
→ Bi(OH)SO4 ⋅ H2O + e− + h+.
The electrons migrate to the surface of the catalyst and
react with O2 adsorbed on the surface of the catalyst to
form a superoxide radical:
The ESR spectra can help us to study the types and
intensities of active radicals in the catalytic process
and then to propose the mechanism of Bi(OH)SO4 ·
H2O photocatalyst for the degradation of pollutants
[44, 45]. The Bi(OH)SO4 · H2O does not emit any sig-
e− + O2 → O•2−.
(2)
Holes can react with H2O to produce hydroxyl radicals
with strong oxidation capacity:
nal in the dark environment, while under UV irradia-
•
h+ + H2O → OH + H+.
•−
(3)
tion, the Bi(OH)SO · H O gives obvious signals of
O2
4
2
Holes, •−, and
are active species and exert
O2
•OH
and •
[46, 47]. The intensity of the two kinds of the
OH
strong oxidation ability in the photochemical reac-
tions, which can react with organic pollutants
adsorbed on the catalyst to achieve the purpose of deg-
radation:
signal increases with time going by. It can be con-
firmed that the main active species in the process of
•−
degradation is
and •
.
OH
O2
To further study the effect of various photoactive
radicals on the degradation of organic pollutants by
Bi(OH)SO4 · H2O catalyst, different free radical trap-
ping agents were used to carry out the capture test.
h+ + organic pollutants → H2O + CO2,
(4)
O•2− + organic pollutants → H2O + CO2,
(5)
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PHOTOCATALYST Bi(OH)SO4 · H2O WITH HIGH PHOTOCATALYTIC PERFORMANCE
REFERENCES
2079
1. M. A. Shannon, P. W. Bohn, M. Elimelech,
J. G. Georgiadis, B. J. Marinas, and A. M. Mayes,
Nature (London, U.K.) 452, 301 (2008).
CB
VB
0
2
4
6
H+/H2
2. A. Mills, R. H. Davies, and D. Worsley, Chem. Soc.
Bi2MoO6
2.27
Bi2SiO5
2.41
BiVO4
2.78
Rev. 22, 417 (1993).
Bi2WO6
2.94
3. N. Savage and M. S. Diallo, J. Nanopart. Res. 7, 331
BiPO4
4.05
(2005).
B(OH)SO4⋅H2O
4. M. A. Malik, A. Ghaffar, and S. A. Malik, Plasma
4.14
Sources Sci. Technol. 10, 82 (2001).
5. D. A. Reddy, R. Ma, M. Y. Choi, and T. K. Kim, Appl.
Surf. Sci. 324, 725 (2015).
6. V. Repousi, A. Petala, Z. Frontistis, M. Antonopoulou,
I. Konstantinou, D. I. Kondarides, and D. Mantzavi-
nos, Catal. Today 284, 59 (2017).
Fig. 4. Band positions of several kinds of bismuth com-
pounds and Bi(OH)SO · H O sample.
4
2
7. P. Fornasiero and K. C. Christoforidis, ChemCatChem
9, 1523 (2017).
•OH + organic pollutants → H2O + CO2.
(6)
8. E. A. Kozlova and V. N. Parmon, Russ. Chem. Rev. 86,
870 (2017).
The position of VB is significant for the oxidation abil-
ity of semiconductors. Figure 4 shows the CV and VB
of some Bi-based photocatalysts. The valence bands of
Bi2MoO6 [48], Bi2WO6 [49], BiPO4 [48], BiVO4 [50],
9. A. V. Puga, Coord. Chem. Rev. 315, 1 (2016).
10. A. V. Vorontsov, E. A. Kozlova, A. S. Besov,
D. V. Kozlov, S. A. Kiselev, and A. S. Safatov, Kinet.
Catal. 51, 801 (2010).
and Bi2SiO5 [51] are 2.27, 2.94, 4.05, 2.78, and 2.41 eV, 11. D. Chen, Q. Hao, Z. Wang, H. Ding, and Y. Zhu,
CrystEngComm 18, 1976 (2016).
respectively. The VB of Bi(OH)SO4 · H2O is more pos-
itive than these photocatalysts, indicating that it might
have stronger oxidation capacity than them. However,
the band gap of 4.64 eV limits its light absorption effi-
ciency. Creating heterojunctions with Bi(OH)SO4 ·
H2O or doping some elements to Bi(OH)SO4 · H2O is
likely to enhance its photocatalytic activity.
12. Q. Hao, X. Niu, C. Nie, S. Hao, W. Zou, J. Ge,
D. Chen, and W. Yao, Phys. Chem. Chem. Phys. 18,
31410 (2016).
13. D. L. Greenaway and G. Harbeke, Optical Properties
and Band Structure of Semiconductors, International
Series of Monographs in the Science of the Solid State
(Elsevier, Amsterdam, 2015).
14. I. M. Tsidilkovski, Band Structure of Semiconductors,
International Series on the Science of the Solid State
(Elsevier, Amsterdam, 2016).
CONCLUSIONS
15. A. L. Linsebigler, G. Lu, and J. T. Yates, Jr., Chem.
In this work, a novel Bi-based photocatalyst,
Bi(OH)SO4 · H2O, with rod-like structure was pre-
pared in a facile method. The band gap of Bi(OH)SO4 ·
H2O is 4.64 eV, and its CB and VB are estimated at
‒0.5 and 4.14 eV, respectively. Positive valence band
makes it have high oxidation capacity theoretically. It
has good photocatalytic activity under UV irradiation
Rev. 95, 735 (1995).
16. I. Tsuji, H. Kato, H. Kobayashi, and A. Kudo, J. Am.
Chem. Soc. 126, 13406 (2004).
17. C. Xing, Y. Zhang, W. Yan, and L. Guo, Int. J. Hydro-
gen Energy 31, 2018 (2006).
18. S.-M. Xu, H. Yan, and M. Wei, J. Phys. Chem. C 121,
2683 (2017).
•−
•
19. J. Xu, C. Qin, Y. Huang, Y. Wang, L. Qin, and
and the main active species are
,
, and holes.
O2 OH
H. J. Seo, Appl. Surf. Sci. 396, 1403 (2017).
The study of this material probably provides a new
resource for synthesizing highly efficient photocata-
lysts through doping other elements or creating het-
erojunctions.
20. L. Xu, C. Qin, Y. Wan, H. Xie, Y. Huang, L. Qin, and
H. J. Seo, J. Taiwan Inst. Chem. E 71, 433 (2017).
21. R. Zhou, J. Wu, J. Zhang, H. Tian, P. Liang, T. Zeng,
P. Lu, J. Ren, T. Huang, and X. Zhou, Appl. Catal., B
204, 465 (2017).
22. T. Umebayashi, T. Yamaki, H. Itoh, and K. Asai, Appl.
ACKNOWLEDGMENTS
Phys. Lett. 81, 454 (2002).
23. J. Zhang, J. Sun, K. Maeda, K. Domen, P. Liu,
M. Antonietti, X. Fu, and X. Wang, Energy Environ.
Sci. 4, 675 (2011).
This work is supported by the National Natural
Science Foundation of China (grant no. 21577132),
the Fundamental Research Funds for the Central
Universities (grant no. 2652015225), the Students
Innovation and Entrepreneurship Training Program
of China University of Geosciences Beijing.
24. T. Morikawa, R. Asahi, T. Ohwaki, K. Aoki, and
Y. Taga, Jpn. J. Appl. Phys. 40, L561 (2001).
25. F. Meng, J. Li, Z. Hong, M. Zhi, A. Sakla, C. Xiang,
and N. Wu, Catal. Today 199, 48 (2013).
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A Vol. 92 No. 10 2018

2080
HAOJIE LU et al.
26. Z. Chen, P. Cai, J. Chen, X. Liu, L. Zhang, L. Lan, 39. L. He, L. Chen, and Y. Xu, Interfacial Struct., Mater.
J. Peng, Y. Ma, and Y. Cao, Adv. Mater. 26, 2586
Charact. 125, 1 (2017).
(2014).
40. L. Hamadou, A. Kadri, and N. Benbrahim, Appl. Surf.
27. C. Wen, A. Yin, and W.-L. Dai, Appl. Catal., B 160,
Sci. 252, 1510 (2005).
730 (2014).
41. G. A. Marking and M. G. Kanatzidis, Chem. Mater. 7,
28. X. Liu and H. Bai, Powder Technol. 237, 610 (2013).
1915 (1995).
29. C. Bhattacharya, H. C. Lee, and A. J. Bard, J. Phys.
42. F. Cardon and W. Gomes, J. Phys. D 11, L63 (1978).
Chem. C 117, 9633 (2013).
43. J. Bandara and U. W. Pradeep, Thin Solid Films 517,
30. M. Zhang, X. Bai, D. Liu, J. Wang, and Y. Zhu, Appl.
952 (2008).
Catal., B 164, 77 (2015).
44. D. C. Hurum, A. G. Agrios, K. A. Gray, T. Rajh, and
31. S. Zhang, S. Zhang, and L. Song, Appl. Catal., B 152,
M. C. Thurnauer, J. Phys. Chem. B 107, 4545 (2003).
129 (2014).
32. Q. Hao, S. Hao, X. Niu, X. Li, D. Chen, and H. Ding, 45. T. A. Lozinova, A. V. Lobanov, and A. V. Lander, Russ.
Chin. J. Catal. 38, 278 (2017).
J. Phys. Chem. A 89, 1492 (2015).
33. E. Garciacaro, P. Mann, and A. Escalona, Mar. Petrol.
46. E. Finkelstein, G. M. Rosen, and E. J. Rauckman,
Geol. 28, 126 (2011).
Arch. Biochem. Biophys. 200, 1 (1980).
34. E. A. Tveritinova, Y. N. Zhitnev, S. A. Chernyak,
E. A. Arkhipova, S. V. Savilov, and V. V. Lunin, Russ. J.
Phys. Chem. A 91, 448 (2017).
35. Z. B. Lei, W. S. You, M. Y. Liu, G. H. Zhou, T. Takata,
M. Hara, K. Domen, and C. Li, Chem. Commun.,
2142 (2003).
47. Y. Noda, K. Anzai, A. Mori, M. Kohno, M. Shinmei,
and L. Packer, Biochem. Mol. Biol. Int. 42, 35 (1997).
48. X. Lin, D. Liu, X. Guo, N. Sun, S. Zhao, L. Chang,
H. Zhai, and Q. Wang, J. Phys. Chem. Solids 76, 170
(2015).
49. Y. Zheng, K. Lv, X. Li, K. Deng, J. Sun, L. Chen,
L. Cui, and D. Du, Chem. Eng. Technol. 34, 1630
(2011).
36. H. Wu, J. Fan, Y. Yang, E. Liu, X. Hu, Y. Ma, X. Fan,
and C. Tang, Russ. J. Phys. Chem. A 89, 1189 (2015).
37. C. Liu, Y. Zhang, F. Dong, A. H. Reshak, L. Ye,
N. Pinna, C. Zeng, T. Zhang, and H. Huang, Appl.
Catal., B 203, 465 (2017).
50. C. Li, P. Zhang, R. Lv, J. Lu, T. Wang, S. Wang,
H. Wang, and J. Gong, Small 9, 3951 (2013).
38. Q. Xu, J. Yu, J. Zhang, J. Zhang, and G. Liu, Chem. 51. D. Liu, W. Yao, J. Wang, Y. Liu, M. Zhang, and Y. Zhu,
Commun. 51, 7950 (2015). Appl. Catal., B 172, 100 (2015).
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A
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