A Z-scheme visible-light-driven Ag/Ag3PO4/Bi2MoO6 photocatalyst: Synthesis and enhanced photocatalytic activity

Article abstract of DOI:10.1039/c5ra22110b

A Ag/Ag₃PO₄/Bi₂MoO₆ hybrid was successfully prepared for the first time via an in situ precipitation method. The as-prepared Ag/Ag₃PO₄/Bi₂MoO₆ hybrid included Ag₃PO₄ nanoparticles (NPs) as well as Ag NPs assembling on the surface of Bi₂MoO₆ nanosheets. Under visible light irradiation (λ > 420 nm), the Ag/Ag₃PO₄/Bi₂MoO₆ hybrid photocatalyst degraded rhodamine B (Rh B) efficiently and showed much higher photocatalytic activity than pure Ag₃PO₄, Bi₂MoO₆, Ag/Ag₃PO₄, Ag/Bi₂MoO₆, or Ag₃PO₄/Bi₂MoO₆. It was elucidated that the excellent photocatalytic performance of Ag/Ag₃PO₄/Bi₂MoO₆ for the degradation of Rh B under visible light could be ascribed to the efficient separation of photogenerated electrons and holes through the Z-scheme system composed of Ag₃PO₄, Ag and Bi₂MoO₆, in which Ag NPs acted as the charge transmission-bridge. The quenching effects of different scavengers illustrated that O₂^- and h⁺ played the major role in Rh B degradation.

Full text of DOI:10.1039/c5ra22110b

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Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
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A
Z-Scheme
Visible-Light-Driven
Ag/Ag PO /Bi MoO
3 4 2 6
photocatalyst: Synthesis and Enhanced Photocatalytic Activity
﹡
Xue Lin, Jing Hou, Shanshan Jiang, Zhe Lin, Miao Wang, and Guangbo Che
A Ag/Ag
prepared Ag/Ag
Bi MoO nanosheets. Under visible light irradiation (λ > 420 nm), the Ag/Ag
rhodamine B (Rh B) efficiently and showed much higher photocatalytic activity than pure Ag
Ag/Bi MoO , or Ag PO /Bi MoO . It was elucidated that the excellent photocatalytic performance of Ag/Ag
3
PO
4
/Bi
2
MoO
6
hybrid was successfully prepared for the first time via an in-situ precipitation method. The as-
MoO hybrid included Ag PO nanoparticles (NPs) as well as Ag NPs assembling on the surface of
PO /Bi MoO hybrid photocatalyst degraded
3
4
PO /Bi
2
6
3
4
2
6
3
4
2
6
3
PO
4
, Bi
2
MoO
6
, Ag/Ag
3
PO
4
,
2
6
3
4
2
6
3
PO /Bi MoO
4
2
6
for the degradation of Rh B under visible light could be ascribed to the efficient separation of photogenerated electrons
and holes through the Z-scheme system composed of Ag PO , Ag and Bi MoO , in which the Ag NPs acted as the charge
3
4
2
6
•
2
－
+
transmission-bridge. The quenching effects of different scavengers illustrated that O
Rh B degradation.
and h played the major role in the
3 4
blue (MB) under visible light irradiation. However, Ag PO is
1
. Introduction
subject to stability issues because it is prone to photoreduction
and decomposition if no sacrificial reagent is supplied, which
greatly hinders its practical application in the environmental
Semiconductors-based photocatalysis is
environmental friendly technology to solve the environmental
contamination issues [1-4]. Exploring high-efficiency
semiconductor photocatalysts is of great importance to transform
this technology into practical applications. Unfortunately, most
a
promising
0
management. It has been reported that elemental silver Ag on
the surface of Ag PO may act as an electron acceptor to enhance
3
4
the charge separation and prevent the reductive decomposition of
Ag PO [28]. In addition, metallic silver species can significantly
widely applied semiconductor photocatalysts, such as TiO
SiO , and CuO [5-9] are just active under UV-light irradiation,
2
, ZnO,
3
4
2
improve the visible light absorption efficiency due to the effect of
surface plasmon resonance. In addition, with more and more
which greatly hinders their further applications under solar light.
Therefore, great efforts have been made to synthesize efficient
visible-light-driven photocatalysts such as BiVO
and BiOX (X = Cl, Br, or I) [10-15]. Among these visible-light
catalysts, Bi MoO has been found to reveal excellent visible-light-
attention has been paid to the mechanism of Ag/Ag
photocatalysts, the by-product Ag has been found to be a charge
transmission bridge in the Ag/Ag PO -based Z-scheme systems. It
3 4
PO -based
4 2 6 2 6
, Bi WO , Bi MoO ,
3
4
2
6
has been reported that these Z-scheme systems can not only
facilitate the charge separation but also retain the high reducibility
and oxidability of the remaining electrons and holes for the
corresponding photocatalysts [28-30]. Recently, there are a few
reports on the photocatalytic activity evaluation of Ag/Ag PO -
driven photocatalytic activity for water splitting and/or for the
degradation of organic contaminants [16,17]. However, further
research on the improvement of the photocatalytic efficiency of
2 6
Bi MoO is still indispensable due to its poor quantum yield.
3
4
Among a variety of methods, the constructions of hybrid
photocatalysts and heterostructures have been shown to be
effective approaches for enhancing photocatalytic performance
for the degradation of organic contaminants. So far, a variety of
3 4
based Z-scheme systems, for instance Ag/Ag PO /SiC [28],
Ag/Ag PO /g-C N [29], and Ag/Ag PO /WO −x [30]. Thus, by
3
4
3
4
3
4
3
2 6 3 4
combining Bi MoO and Ag/Ag PO particles to constitute a Z-
scheme photocatalyst, both the utilization of visible light and the
surface–interface charge transfer efficiency of photo-generated
carriers could be enhanced. However, until now, there is few
Bi
C/Bi
21], ZnTiO
/Bi MoO
photocatalytic property of Bi
Ag PO is well known as a photosensitive material and
2
MoO
6
-based photocatalysts such as TiO
[19], graphene/Bi MoO
/Bi MoO [22], Ag/AgBr/Bi
[24] have been fabricated for improving the
MoO
2
/Bi
2
MoO
6.55/Bi
6
[18],
MoO
2 6
MoO [23], and g-
2
MoO
6
2
6
[20], Bi3.64Mo0.36
O
2
6
[
C
3
2
6
report focusing on the assembly of Bi
2 6
MoO nanosheet with
3
N
4
2
6
Ag/Ag PO NPs. Furthermore, no attention has been paid to the
3
4
2
6
.
3 4 2 6
mechanism of Ag/Ag PO /Bi MoO photodegradation process
3
4
under visible light irradiation, which has remained unclear to date.
Herein, we report a successful attempt at the fabrication of
Ag/Ag PO /Bi MoO hierarchical nanostructures via an in-situ
regarded as an appropriate candidate for the construction of
hybrid photocatalysts with other semiconductors [25,26]. Zhang
3
4
2
6
and co-workers reported the Ag
which was fabricated by covering the surface of spherical Bi
with Ag PO nanoparticles through deposition–precipitation
3
PO
4
/Bi
2
MoO
6
photocatalyst,
facile in-situ precipitation method, and the photocatalytic activity
of these nanostructures was investigated by measuring the
degradation of rhodamine B (Rh B) under visible light (λ > 420 nm).
2
MoO
6
3
4
process [27]. This hybrid showed remarkably high photocatalytic
efficiency for the degradation of rhodamine B (Rh B) and methyl
Furthermore,
Ag/Ag PO /Bi
trapping experiments. Finally, the stability of the
the
photocatalytic
mechanism
of
the
3
4
2
MoO
6
hybrid was investigated via reactive species
Key Laboratory of Preparation and Application Environmentally Friendly Materials
of Ministry of Education, Jilin Normal University, Siping 136000, P. R. China
E-mail:jlsdlinxue@126.com; Fax: +86 434 329 1890; Tel: +86 156 9434 9717
See DOI: 10.1039/x0xx00000x
Ag/Ag PO
3 4
/Bi
2
MoO
6
hybrid photocatalyst was also examined.
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min. Then the solution was exposed to visible light irradiation
under magnetic stirring. At given time intervals, 4 mL of the
suspension was periodically collected and analyzed after
centrifugation. The Rh B concentration was analyzed by a UV-2550
spectrometer to record intensity of the maximum band at 552 nm
in the UV-vis absorption spectra.
2
. Experimental
2
.1 Preparation of photocatalysts
.1.1 Preparation of Bi MoO nanosheets
All reagents for synthesis and analysis were commercially
available and used without further treatments. The Bi MoO
nanosheets were synthesized through a facile hydrothermal
method. Briefly, a solution of Bi(NO (0.40 mol/L, 5 mL H O) was
stirred for 30 min. Then, (NH Mo 24 (0.20 mol/L, 5 mL H O) was
2
2
6
2
6
2
.4 Active species trapping experiments
3
)
O
3
2
For detecting the active species during photocatalytic
4
)
6
7
2
reactivity, some sacrificial agents, such as 2-propanol (IPA),
disodium ethylenediamine tetraacetic acid (EDTA-2Na), and 1,4-
benzoquinone (BQ) were used as the hydroxyl radical (•OH)
added to the suspension, which was stirred magnetically for
another 30 min. After carefully adjusting the pH value of 3 using
3 2
25 wt% NH ·H O solution, the mixed solution was transferred into
+
•−
2
)
scavenger, hole (h ) scavenger and superoxide radical (O
a 20 mL Teflon-lined steel autoclave, which was heated in an oven
at 160 C for 24 h. Then the system was allowed to cool to room
temperature naturally. At last, the obtained samples were
collected and washed with ethanol and distilled water several
times, and dried at 70 C for 2 h.
o
scavenger, respectively. The method was similar to the former
photocatalytic activity test with the addition of 1 mmol of
quencher in the presence of Rh B.
o
2
.1.2 Preparation of Ag/Ag
The Ag/Ag PO /Bi MoO
synthesized through an in-situ precipitation method at room
temperature. In a typical process, Bi MoO nanosheets (500 mg)
were dispersed in 100 mL deionized water by ultrasound for 30
min, and then 50 mL 0.0075 M AgNO aqueous solution was
dropped into the Bi MoO dispersed solution. After stirring for 15
min, a 50 mL of 0.0025 M Na PO aqueous solution was added to
3
PO
4
/Bi
2
MoO
6
photocatalyst
3. Results and discussion
3
4
2
6
hybrid photocatalyst was
Fig. 1 displays the XRD pattern of the Ag/Ag
hybrid photocatalyst, together with those of pure Ag
Bi MoO , Ag/Bi MoO , Ag/Ag PO , and Ag PO /Bi MoO samples.
As can be seen in Fig. 1, Ag PO is a cubic phase (JCPDS NO. 06-
0505), while Bi MoO is an orthorhombic crystal (JCPDS NO. 21-
0102). It is observed that no peaks assigned to Ag were found in
the as-prepared Ag/Ag PO /Bi MoO , Ag/Ag PO , and Ag/Bi MoO
3
PO
4
/Bi
2
MoO
PO
6
3
4
,
2
6
2
6
2
6
3
4
3
4
2
6
3
4
3
2
6
o
2
6
3
4
3
4
2
6
3
4
2
6
the above solution drop by drop under magnetic stirring. The pH
value was adjusted to 3 by adding 1.0 M NaOH. The resulting
suspension was stirred in the dark for another 30 min. Then, the
suspension was irradiated by a 300 W Xe lamp equipped with an
optical cut-off filter (λ > 420 nm) for 30 min. Finally, the
precipitate was washed with deionized water for 3 times and
samples, owing to its low amount. Moreover, the changes of all
diffractions and lattice parameters were not detectable, which
indicates that Ag related species resided in the lattice sites and
have no separate phase. No obvious peaks of the Ag
were detected in the patterns of Ag/Ag PO /Bi
Ag PO /Bi
composites possess the same crystal structure. This may be
resulted from the low concentration or small crystal size of Ag PO
3
PO
4
phases
3
4
2
MoO
6
and
3
4
2
MoO6, suggesting that all the as-synthesized
o
collected by centrifugation, and then dried at 60 C in the vacuum
drying oven. The theoretical value of Ag
3
PO
4
loading amount was
4
MoO , Ag/Ag PO ,
3
4
.
1
0 wt%. For comparison, pure Ag PO , Ag/Bi
3
4
2
6
3
and Ag PO /Bi MoO samples were prepared under the same
3
4
2
6
conditions.
2
.2. Characterization of photocatalysts
The crystal structures of the samples were characterized by X-
ray diffraction (XRD) on a Rigaku (Japan) D/max 2500 X-ray
diffractometer (Cu radiation, 0.154 18 nm). The
K
α
λ =
morphologies and structure details of the as-synthesized samples
were detected using field emission scanning microscopy (SEM,
JSM-6510) and transmission electron microscopy (TEM, JEM-
2
100F). X-ray photoelectron spectroscopy (XPS) analysis was
performed with an ESCALa-b220i-XL electron spectrometer
VGScientific, England) using 300 W Al K radiation. The optical
(
α
properties were obtained by the photoluminescence (PL)
measurement using HR800 LabRam Infinity Spectro photometer
excited by a continuous He-Cd laser with a wavelength of 325 nm
at a power of 50 mW. The UV-vis diffuse reflectance spectra (DRS)
were recorded using a scan UV-vis spectrophotometer (UV-2550).
Fig. 1 XRD patterns of Ag
3
PO
4
, Bi
2
MoO
PO
6
, Ag/Bi
2
MoO
6 3 4
, Ag/Ag PO ,
Ag PO /Bi MoO , and Ag/Ag
3
4
2
6
3
4
/Bi MoO
2
6
hybrids.
2
.3. Photocatalytic activities studies
In order to confirm the existence of metallic Ag and Ag PO ,
3
4
The photocatalytic properties of the as-prepared samples
XPS technology has been employed to analyze the surface
element composition and chemical state of Ag/Ag PO /Bi MoO ,
were evaluated using Rh B as a model compound. The Rh B is a
very stable compound, which has been used widely as a
representative reaction for examining the performance of
numerous visible light active photocatalysts. In experiments, the
Rh B solution (0.01 mmol·L , 100 mL) containing 0.02 g of
photocatalyst were mixed in a pyrex reaction glass. A 300 W Xe
lamp (λ > 420 nm) was employed to provide visible light irradiation.
A 420 nm cut-off filter was inserted between the lamp and the
sample to filter out UV light (λ < 420 nm). Prior to visible light
illumination, the suspension was strongly stirred in the dark for 40
3
4
2
6
and the obtained results are shown in Fig. 2. From Fig. 2a, the Ag
+
3
d peaks of Ag/Ag PO /Bi MoO have separated as Ag peaks and
3 4 2 6
0
0
-1
Ag peaks. The peaks at 367.1 and 373.1 eV are attributed to Ag
of Ag PO [28], indicating existence of metallic Ag on the surface of
3
4
Ag/Ag
3
4 2 6
PO /Bi MoO sample. The peaks at 366.4 and 372.3 eV are
+
assigned to Ag of Ag PO [28]. A broad peak in the range of 129 to
3
4
1
34 eV of the P 2p spectrum (Fig. 2b) is observed for the
Ag/Ag PO /Bi MoO sample which is corresponding to the
3
4
2
6
2
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3
+
phosphorus of Ag PO [29]. The results give solid evidence of the
4f ), ascribed to Bi [27]. The characteristic spin-orbital splitting
3
4
5/2
formation of metallic Ag and Ag
of the sample is shown in Fig. 2c. XPS signals of Bi 4f are observed
at binding energies at about 162.9 eV (Bi 4f7/2) and 157.5 eV (Bi
3
PO
4
. The Bi 4f fine XPS spectrum
photoelectrons for Mo 3d (234.8 and 231.6 eV) indicate a six-
valent oxidation state for Mo [27] (Fig. 2d).
6
+
3 4 2 6
Fig. 2 XPS spectra of the as-obtained Ag/Ag PO /Bi MoO sample: (a) Ag 3d spectrum, (b) P 2p spectrum, (c) Bi 4f, (d) Mo 3d spectrum.
The SEM images of Bi MoO , Ag/Bi MoO , Ag PO /Bi MoO
nm. The Ag PO /Bi MoO sample shows the similar absorption
3 4 2 6
2
6
2
6
3
4
2
6
and Ag/Ag
as-prepared Bi
average sizes of about 100 nm and thickness of tens of nanometers
Fig. S1a). The Ag/Bi MoO Ag PO /Bi MoO and
Ag/Ag PO /Bi MoO samples display a similar morphology to pure
Bi MoO (Fig. S1b-d), indicating that low amount Ag PO and Ag
3
PO
4
/Bi
2
MoO
6
samples are revealed in the Fig. S1. The
edge and a broader absorption in the visible region as comparison
with pure Bi MoO . Ag/Bi MoO and Ag/Ag PO samples show
2
MoO
6
particles are composed of nanosheets with
2
6
2
6
3
4
obvious visible-light absorption, which can be attributed to the
surface Plasmon resonance (SPR) of the loading Ag, further
confirming the formation of Ag. The absorption curve of the
Ag/Ag PO /Bi MoO shows distinctly enhanced visible-light
(
2
6
,
3
4
2
6
,
3
4
2
6
2
6
3
4
3
4
2
6
loading did not have any influence on the morphology of Bi
crystals. Moreover, the component and connection of
Ag/Ag PO /Bi MoO were investigated by TEM, as shown in Fig. 3.
Fig. 3a shows the sheet-like structure of the as-synthesized
Bi MoO sample. It can be seen that the sizes of Ag PO crystals
are of 10 - 20 nm (Fig. 3b). From Fig. 3c, it can be clearly found
that the Ag NPs and Ag PO NPs were loaded on the surface of
Bi MoO . Fig. 3d shows the HRTEM image of the as-fabricated
Ag/Ag PO /Bi MoO sample. By measuring the lattice fringes, the
2
MoO
6
absorption compared to the pure Bi
2
MoO
6
and Ag
samples. According to the plot of (ahv) versus energy, as shown in
Fig. 4b, the band gap energies (E ) of Ag PO and Bi MoO have
been calculated to be 2.42 and 2.36 eV, respectively. The band
structure of Ag PO and Bi MoO can be estimated according to
the empirical equations 1 and 2 below;
3 4 2 6
PO /Bi MoO
2
3
4
2
6
g
3
4
2
6
2
6
3
4
3
4
2
6
e
3
4
E
E
VB= X – E + 0.5E
CB =EVB - E
g
(1)
(2)
g
2
6
where EVB is the valence band edge potential, ECB is the conduction
band edge potential, is the electronegativity of the
3
4
2
6
X
resolved interplanar distances are about 0.236, 0.213, and 0.314
nm, which correspond to the (111) plane of Ag, the (210) plane of
semiconductor, which is the geometric mean of the
electronegativity of the constituent atoms, E is the energy of free
electrons on the hydrogen scale (about 4.5 eV), E is the band gap
e
Ag
3
PO
4 2 6
, and the (131) plane of Bi MoO , respectively.
g
Fig. 4a displays the UV-vis diffuse reflectance spectra of
energy of the semiconductor. Thus, the EVB of Ag PO and Bi MoO
6
3
4
2
Bi
2
MoO
6
, Ag
3
PO
4
, Ag/Bi
2
MoO
6
, Ag/Ag
3
PO
4
, Ag
3
PO
4
/Bi
2
MoO
6
, and
are calculated to be 2.67 and 2.33 eV, respectively, and their
corresponding EcB are determined to be 0.25 and -0.31 eV,
respectively. The results are in agreement with the reported works
Ag/Ag
3
PO
4
/Bi
2
MoO
6
. It can be seen that bare Bi
2
MoO
6
exhibits
strong absorbance in wavelengths shorter than 520 nm, and pure
Ag PO shows strong absorbance in wavelengths shorter than 510
[
3 4
28, 22]. The energy band structure diagram of Ag PO , Ag, and
3
4
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Bi MoO is thus schematically illustrated, as shown in Scheme 1.
because the Fermi level of Ag is more negative than the VB of
Bi MoO , and then combine with the electron here. Therefore,
simultaneous electron (I) and hole (II) transfers enhance the
charge separation of Ag PO and Bi MoO
2
6
Under visible light irradiation, both Ag
3
PO
4
and Bi
2
MoO
6
are
2
6
excited, and the photogenerated holes and electrons are in their
conduction and valence band, respectively. The electrons on the
CB of Ag PO can easily shift into metal Ag (electron transfer I:
3
4
2
6
.
3
4
3 4
Ag PO
CB → Ag) through the Schoꢀky barrier because the CB
potential of Ag PO is more negative than the Fermi level of the
3
4
2 6
loaded metal Ag. Meanwhile, the holes on the VB of Bi MoO can
also migrate to metal Ag (hole transfer II: Bi MoO VB → Ag)
2
6
Fig. 3 TEM images of Bi
2
MoO
6
(a), Ag
3
PO
4
(b), Ag/Ag
3
4 2 6 3 4 2 6
PO /Bi MoO (c), and HRTEM image of Ag/Ag PO /Bi MoO (d).
2
Fig. 4(a) UV-vis DRS of as-synthesized samples. (b) the plots of (αhv) versus photon energy (hν) for the band gap energies of Ag
3
PO
4
and Bi
2
MoO
6
.
4
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Scheme 1 Schematic diagram of the separation and transfer of photogenerated charges in the hybrid under visible light irradiation.
The photocatalytic properties of the as-prepared samples
under visible light irradiation were evaluated, as shown in Fig. 5.
photogenerated electrons in the CB of Ag
3 4
PO and holes in the VB
of Bi MoO will shift to the metallic Ag simultaneously and then
2
6
This result clearly demonstrates that the Ag/Ag
hybrid exhibited higher photocatalytic activity than pure Ag
Bi MoO , Ag/Ag PO , Ag/Bi MoO , and Ag PO /Bi MoO , which
suggests that combining Ag/Ag PO and Bi MoO is an efficient
route to enhance their photocatalytic activities. In the presence of
Ag/Ag PO /Bi MoO , almost 100% of the Rh B molecules were
decomposed within 80 min visible light irradiation. The Ag PO NPs
3
PO
4
/Bi
2
MoO
6
combine here, which leads to higher PL intensity. The
recombination in the metallic Ag is benefical for accelerating the
separation of the photogenerated electron-hole pairs in both
3
PO
4
,
2
6
3
4
2
6
3
4
2
6
3
4
2
6
Ag
Ag/Ag
observed that the PL intensity of Ag
that of pure Bi MoO because of the formation of heterojunction
between Ag PO and Bi MoO can efficiently suppress the
3
PO
4
and Bi
2
MoO
improved. In addition, it can be clearly
PO /Bi MoO was lower than
6
, so the photocatalytic performance of
3
PO /Bi MoO
4
2
6
3
4
2
6
3
4
2
6
3
4
2
6
and Ag NPs coating can improve the visible light absorption
efficiency (Fig. 4a), which is beneficial for the hybrid to photolyze
Rh B. In addition, efficient Z-scheme system can separate the
photoinduced charges effectively, thus enhancing the
photocatalytic performance of Ag/Ag PO /Bi MoO .
3
4
2
6
recombination of the photogenerated electron−hole in the hybrid.
On the basis of the above results, the Ag/Ag PO /Bi MoO system
3
4
2
6
is a typical Z-scheme photocatalyst rather than heterojunction
photocatalyst. It is suggested that rich electrons in the CB of
3
4
2
6
The photoluminescence (PL) emission spectra were studied to
investigate the charge recombination and transfer behaviour of the
Bi
2 6 3 4
MoO and holes in the VB of Ag PO participate in the reduction
reaction of dissolved O and the oxidation of Rh B, respectively.
2
Ag/Ag
3
PO
4
/Bi
2
MoO
6
photocatalyst, as shown in Fig. 6. It is well-
The stability and reusability of Ag/Ag
were evaluated by the cycling degradation experiment, as shown
in Fig. S2. The results revealed that the Ag/Ag PO /Bi MoO did
not show obvious decrease of photocatalytic degradation activity
under visible light, indicating that the Ag/Ag PO /Bi MoO hybrid
3 4 2 6
PO /Bi MoO photocatalyst
known that the recombination of electron−hole pairs can release
energy in the form of PL emission. In general, a lower PL intensity
indicates lower recombination of charge carriers, leading to higher
3
4
2
6
photocatalytic activity. However, the Ag/Ag
higher photocatalytic activity showed a higher PL intensity than
that of Bi MoO and Ag PO /Bi MoO . The higher PL intensity of
Ag/Ag PO /Bi MoO would be resulted from higher recombination
3
PO
4
/Bi
2
MoO
6
with the
3
4
2
6
photocatalyst is sufficient stable for photocatalytic degradation of
Rh B.
2
6
3
4
2
6
3
4
2
6
of photogenerated electron-hole pairs in the metallic Ag. The
Fig. 5 Photodegradation efficiencies of Rh B as a function of irradiation time
Fig. 6 Room temperature PL spectra of as-synthesized samples.
for different photocatalysts.
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To investigate the photocatalytic mechanism of the
Ag/Ag PO /Bi MoO hybrid, the effect of scavengers on the
degradation of Rh B was tested in the photocatalytic oxidation
process and the results are shown in Fig. 7. As revealed in Fig. 7,
Acknowledgment
This work was supported by the Science and Technology
Research Project of the Department of Education of Jilin Province
3
4
2
6
(
2015220).
3 4 2 6
under the visible-light irradiation of the Ag/Ag PO /Bi MoO sample,
the photodegradation rate of Rh B had slight decrease after the
addition of hydroxyl radical scavenger IPA, indicating that •OH was
not the main reactive specie in the photocatalytic process. In
contrast, the photocatalytic degradation of Rh B was significantly
repressed in presence of EDTA-2Na and BQ. According to these
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3
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2 6 3 4 2 6
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6
3
4
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DOI: 10.1039/C5RA22110B
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RSC Advances
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►
►
A novel Z-Scheme Ag/Ag
3
PO
4
/Bi MoO
2
6
photocatalyst was successfully synthesized.
Ag/Ag PO /Bi MoO hybrid photocatalyst exhibited enhanced photocatalytic activity.
6
3
4
2