Facile Preparation of AgI/Bi2MoO6 Heterostructured Photocatalysts with Enhanced Photocatalytic Activity

Article abstract of DOI:10.1002/ejic.201501260

Bi₂MoO₆ microspheres were modified by loading AgI nanoparticles on their surfaces by a facile deposition/precipitation approach. The as-prepared AgI/Bi₂MoO₆ heterostructured photocatalysts exhibit much higher photocatalytic activities for the degradation of rhodamine B (RhB) and bisphenol A (BPA) than P25, AgI, Bi₂MoO₆, and a mechanical mixture of AgI and Bi₂MoO₆. The composite with 20 wt.-% AgI shows the highest degradation efficiency. The enhanced photocatalytic properties of the AgI/Bi₂MoO₆ heterostructures are attributed to their larger surface areas, extended absorption in the visible-light range, and efficient separation of photoinduced carriers at the interfaces of the AgI and Bi₂MoO₆ nanocrystals. The AgI/Bi₂MoO₆ photocatalyst is stable during the catalytic reaction and can be used repeatedly. Moreover, O₂^·- and h⁺ were verified as the main active species in the decomposition of organic pollutants. A possible photocatalytic mechanism is also proposed.

Full text of DOI:10.1002/ejic.201501260

DOI: 10.1002/ejic.201501260
Full Paper
Heterogeneous Photocatalysts
Facile Preparation of AgI/Bi2MoO6 Heterostructured
Photocatalysts with Enhanced Photocatalytic Activity
Ming Xu[a] and Wei-De Zhang*[a]
Abstract: Bi2MoO6 microspheres were modified by loading AgI of the AgI/Bi2MoO6 heterostructures are attributed to their
nanoparticles on their surfaces by a facile deposition/precipita- larger surface areas, extended absorption in the visible-light
tion approach. The as-prepared AgI/Bi2MoO6 heterostructured range, and efficient separation of photoinduced carriers at the
photocatalysts exhibit much higher photocatalytic activities for interfaces of the AgI and Bi2MoO6 nanocrystals. The AgI/
the degradation of rhodamine B (RhB) and bisphenol A (BPA) Bi2MoO6 photocatalyst is stable during the catalytic reaction
than P25, AgI, Bi2MoO6, and a mechanical mixture of AgI and and can be used repeatedly. Moreover, O2·– and h+ were verified
Bi2MoO6. The composite with 20 wt.-% AgI shows the highest as the main active species in the decomposition of organic pol-
degradation efficiency. The enhanced photocatalytic properties lutants. A possible photocatalytic mechanism is also proposed.
Introduction
mains a challenge.[18] Therefore, to overcome these drawbacks,
Bi2MoO6 is used frequently to build heterojunction systems,
such as Bi2O2CO3/Bi2MoO6,[4] Ag/Bi2MoO6,[19] and Bi2MoO6/RGO
(RGO = reduced graphene oxide).[20] Recently, silver halide (AgX;
X = Cl, Br, and I) semiconductors have been reported to exhibit
excellent photocatalytic efficiency for the degradation of or-
ganic pollutants.[10–12] In addition to the components of com-
posite catalysts, their morphology is also a significant factor
that determines their photocatalytic performance.[21,22] There-
fore, to produce closer and more sufficient contacts between
semiconductors, many AgX-based composites have been con-
structed by loading silver halide nanoparticles on the sub-
strates.[23,24]
Environmental issues are a major problem faced by humans in
the 21st century. Photocatalytic technology provides an ideal
solution for pollution treatment, and semiconductor photocata-
lysts that directly harvest and make use of solar energy at ambi-
ent temperature can effectively degrade organic pollutants in
wastewater and exhaust gas.[1] Among various semiconductors,
TiO2 has been the most widely studied photocatalyst in recent
decades. However, its wide band gap and the rapid recombina-
tion of the photoinduced carriers in TiO2 seriously inhibit its
applications.[2,3]
The construction of heterostructured photocatalysts by cou-
pling two semiconductors with matched energy-band struc-
tures has become an effective approach to enhance their pho-
tocatalytic performance. The strategy facilitates the separation
of photogenerated electrons and holes through charge transfer
between the semiconductors.[4,5] In recent years, some new
heterostructured photocatalysts with high visible-light response
have been designed and developed, for example, Bi-based,[6–9]
Ag-based,[10–12] and g-C3N4-based[13–15] composite catalysts
have attracted great attention. Bi2MoO6 (BMO) is an Aurivillius-
phase perovskite oxide that consists of [Bi2O2]2+ layers inter-
leaved by double slabs of MoO42–. On one hand, it shows supe-
rior photocatalytic activity owing to its peculiar band structure
and crystal structure.[16,17] On the other hand, because of the
bottleneck caused by the poor quantum yield, which is caused
by its limited absorption of light in the visible region and the
rapid recombination of photoinduced electrons and holes, the
practical photodegradation of organics on pure Bi2MoO6 re-
In this study, AgI/Bi2MoO6 heterostructured photocatalysts
were prepared through
a two-step process. Hierarchical
Bi2MoO6 flowerlike microspheres were synthesized first by a sol-
vothermal process. Then, the obtained Bi2MoO6 microspheres,
as the host material, were modified by AgI nanoparticles
through a facile deposition–precipitation process. The photo-
catalytic activities of the samples were evaluated for the degra-
dation of the model dye rhodamine B (RhB) and the colorless
pollutant bisphenol A (BPA) under visible-light irradiation. A
possible photocatalytic degradation mechanism on the AgI/
Bi2MoO6 hierarchical nanocomposites will be discussed in de-
tail. Moreover, the recyclability of AgI/Bi2MoO6 in the photocat-
alytic process was also studied.
Results and Discussion
The XRD patterns of BMO, AgI, and 0.2AgI/BMO (20 wt.-% AgI)
are shown in Figure 1; all of the diffraction peaks of pure BMO
and AgI can be indexed clearly to orthorhombic Bi2MoO6
(JCPDS no. 21-0102) and hexagonal AgI (JCPDS no. 09-0374),
respectively. No diffraction peaks of impurities were found in
the patterns. In the XRD pattern of 0.2AgI/BMO, in addition to
[a] School of Chemistry and Chemical Engineering, South China University of
Technology,
381 Wushan Road, Guangzhou 510640, People's Republic of China
E-mail: zhangwd@scut.edu.cn
ORCID(s) from the author(s) for this article is/are available on the WWW
under http://dx.doi.org/10.1002/ejic.201501260.
Eur. J. Inorg. Chem. 2016, 826–831
826
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
all of the peaks of Bi2MoO6, apparent diffraction peaks at 2θ = noparticles, which are uniformly deposited on the surfaces of
22.32, 23.71, 39.20, and 46.31°, which correspond to the (002), the Bi2MoO6 microspheres. This suggests that the Bi2MoO6
(100), (110), and (112) crystal facets of AgI, are also observed; serves as a carrier for the dispersion of AgI to prevent the con-
therefore, the XRD pattern demonstrates the coexistence of glomeration of the AgI nanoparticles. This has been confirmed
Bi2MoO6 and AgI in the 0.2AgI/BMO sample.
in other reports.[14,23,25]
The microstructure of the AgI/Bi2MoO6 hierarchical nano-
composites was further examined by transmission electron mi-
croscopy (TEM). The low-magnification TEM image of 0.2AgI/
Bi2MoO6 is shown in Figure 3A. Numerous spherelike AgI nano-
particles are embedded or anchored on the Bi2MoO6 nano-
platelets. The corresponding high-resolution TEM (HRTEM) im-
age of 0.2AgI/Bi2MoO6 in Figure 3B displays the lattice fringes
of the crystals with interplanar spacings of 0.375 and 0.269 nm,
which correspond to the (002) plane of AgI (JCPDS no. 09-0374)
and the (060) plane of Bi2MoO6 (JCPDS no. 21-0102), respec-
tively. The TEM and HRTEM results further confirm that the en-
tire surface of the Bi2MoO6 microspheres is covered by the AgI
nanoparticles, and an AgI/Bi2MoO6 heterojunction is formed by
these two semiconductors.
Figure 1. XRD patterns of BMO, AgI, and 0.2AgI/BMO.
The SEM images of the as-obtained samples are displayed in
Figure 2. AgI exhibits a morphology with many blocks of un-
even size (Figure 2A). The high-magnification SEM image of AgI
in Figure 2B shows clearly that the blocks result from the ag-
glomeration of numerous AgI nanoparticles that are dozens of
nanometers in size. Bi2MoO6 comprises many flowerlike micros-
pheres with diameters of ca. 1–2 μm (Figure 2C). As shown in
Figure 2D, the Bi2MoO6 microspheres are constructed by the
self-assembly of numerous nanoplatelets. However, in the im-
ages of the composite 0.2AgI/BMO (Figure 2E and F), large AgI
particles cannot be observed. In contrast, the AgI exists as na-
Figure 3. (A) TEM and (B) HRTEM images of 0.2AgI/BMO.
The photocatalytic degradation of organics is an interfacial
reaction that greatly depends on the morphology of the cata-
lyst. Larger surface areas are favorable for the adsorption of
organic compounds and provide more active sites for photocat-
alytic reactions. Of the prepared samples, AgI possesses the
smallest surface area (4.98 m2/g) because of the severe aggre-
gation of the AgI nanoparticles. The surface area of the BMO
hierarchical microspheres is 11.9 m2/g. Compared with those of
pure AgI and BMO, the AgI/BMO composites with 10, 20, and
30 wt.-% AgI display larger surface areas of 12.5, 15.7, and
14.1 m2/g, respectively. This is because AgI is loaded on
Bi2MoO6 in the form of nanoparticles instead of large crystals,
as observed in the SEM and TEM images. However, if too much
AgI is present, it also forms agglomerates with tight and even
surfaces, which are unfavorable for the enlargement of the sur-
face area. Of the prepared samples, 0.2AgI/BMO shows the opti-
mum surface area.
The photocatalytic performances of the prepared catalysts
were evaluated for the degradation of RhB (8 ppm) and BPA
Figure 2. SEM images of (A and B) AgI, (C and D) BMO, (E and F) 0.2AgI/BMO,
and (G) 0.2AgI/BMO after four cycles of photodegradation reaction.
Eur. J. Inorg. Chem. 2016, 826–831
www.eurjic.org
827
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
(15 ppm) under visible-light irradiation. As displayed in Fig- mercial P25 in 2 h. The degradation rates of BPA on BMO mic-
ure 4A, commercial P25 exhibits rather poor photocatalytic effi- rospheres, AgI nanoparticles, and M-0.2AgI/BMO were 19.6,
ciency towards RhB, and only 22.8 % of the RhB decomposed 30.1, and 32.0 %, respectively. The maximum removal ratio
under visible-light illumination in 140 min. However, 83.8 and (59.2 %) was obtained on 0.2AgI/BMO under the same condi-
91.7 % of the RhB was degraded in 60 min on BMO hierarchical tions. As shown in the corresponding temporal evolution of the
microspheres and AgI nanoparticles, respectively. After the dep- absorption spectra (Figure 5B), the intensities of the peaks of
osition of AgI nanoparticles on the surface of Bi2MoO6 micro- BPA at λ = 276 and 225 nm decreased gradually as the irradia-
spheres, the obtained AgI/BMO heterostructured photocatalysts tion time increased. These results manifest that 0.2AgI/BMO is
displayed enhanced activities. Among the AgI/BMO composites, an excellent visible-light-induced photocatalyst, and the en-
0.2AgI/BMO shows the highest photocatalytic activity with a hanced performance is ascribed to the heterojunction formed
degradation rate of 93.6 % in only 40 min. The corresponding in the composite. The difference in the photocatalytic activities
absorption spectra of the solution decomposed on 0.2AgI/BMO of 0.2AgI/BMO and M-0.2AgI/BMO mainly depends on their dif-
at different times reveal that the characteristic absorption peak ferent preparation methods.[18] The contacts between the AgI
of the solution gradually shifted from λ = 554 to 496 nm and blocks and the BMO microspheres are loose and insufficient in
the intensity of the peak decreased quickly to approximately the M-0.2AgI/BMO sample obtained by mechanical mixing, and
zero within 140 min (Figure 4B). The blueshift of the characteris- therefore the improvement in photocatalytic activity is only
tic absorption peak of RhB indicates that RhB was deethylated negligible compared to those of pure BMO and AgI.
in a stepwise manner, that is, the ethyl groups were removed
one by one. As shown in Figure 4B, the peak intensity in the
UV region (200 < λ < 400 nm) also evidently decreases as the
irradiation time increases, which further proves that the aro-
matic ring in the RhB molecule is destroyed.[18] However, M-
0.2AgI/BMO (mechanically mixed AgI and BMO) with the same
composition as that of 0.2AgI-BMO shows a much lower degra-
dation rate (72 %) than that of 0.2AgI/BMO (93.6 %) in 40 min.
Figure 5. (A) Photodegradation of BPA on the photocatalysts under visible-
light irradiation; (B) time-dependent optical absorption spectra of BPA on
0.2AgI/BMO.
Stability is a vital index for the practical application of a pho-
tocatalyst. To evaluate the stability and reusability of 0.2AgI/
BMO, the catalyst was reused to degrade RhB for four cycles
under the same conditions. In each run, the catalyst was col-
lected, washed with acetone and deionized water, dried at 60 °C
for 12 h, and then used for the next run. Clearly, no significant
Figure 4. (A) Photodegradation of RhB on the photocatalysts under visible-
deactivation occurred during four cycles (Figure 6A); therefore,
light irradiation; (B) time-dependent optical absorption spectra of RhB on
0.2AgI/BMO has good reusability. Additionally, the X-ray diffrac-
tion patterns in Figure 6B reveal that there are no observable
phase or structure differences in the samples before and after
each repetition test. Furthermore, SEM observations (Figure 2F
and G) also reveal little changes to the morphology of 0.2AgI/
BMO after four cycles. These results indicate that the AgI/BMO
hierarchical heterostructure obtained by the facile deposition/
precipitation method is highly stable and can be used repeat-
edly.
0.2AgI/BMO.
BPA is one of the endocrine-disrupting chemicals (EDCs), and
toxicity tests have revealed that it may cause various adverse
effects to aquatic organisms even at low exposure levels.[26] To
eliminate the sensitization effect of dyes, we also selected color-
less BPA as a target substrate to measure the photocatalytic
activity of the prepared samples under visible-light illumination.
The changes of BPA concentration versus the reaction time on
P25, BMO, AgI, 0.2AgI/BMO, and M-0.2AgI/BMO are shown in
To study the possible photocatalytic mechanism for the AgI/
Figure 5A. The photodegradation results for BPA are similar to BMO heterojunction system, active-species (h+, O2·–, and HO·)
those for RhB. Only 13.5 % of the BPA was degraded on com- trapping experiments were performed during the degradation
Eur. J. Inorg. Chem. 2016, 826–831
www.eurjic.org
828
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
absorption is enhanced and redshifted within the visible-light
range compared with that of BMO. These results confirm that
the visible-light response of the composites is improved by the
introduction of AgI to the BMO matrix, which can lead to the
formation of more electron–hole pairs and, thus, enhance the
photocatalytic activity. The band-gap energy (Eg) of a semicon-
ductor can be estimated by the formula αhν = A(hν – Eg)n/2, in
which α, h, ν, and A are the absorption coefficient, Plank con-
stant (eV s), light frequency (Hz) and a constant, respectively.[27]
In addition, the value of n depends on the optical-transition
type of the semiconductor (n = 1 for a direct transition and n =
4 for an indirect transition) and is 1 for both Bi2MoO6 and
AgI.[28,29] Therefore, from the plots of (αhν)1/2 versus (hν) in Fig-
ure 8B, the Eg values of AgI and BMO can be calculated to be
2.67 and 2.6 eV, respectively.
Figure 6. (A) Reusability of 0.2AgI/BMO for the photocatalytic degradation of
RhB; (B) XRD patterns of 0.2AgI/BMO and 0.2AgI/BMO after four cycles.
of RhB on 0.2AgI/BMO. As shown in Figure 7, the addition of
tert-butyl alcohol (TBA) as a hydroxyl radical (HO·) scavenger
hardly affects the photocatalytic degradation of RhB. However,
when the hole (h+) scavenger disodium ethylenediaminetetra-
acetate (EDTA-2Na) was added to the reaction system, the de-
composition rate decreased to ca. 80 % in 140 min. Moreover,
the degradation efficiency was inhibited drastically by the addi-
·–
tion of the O2 scavenger p-benzoquinone (BQ). These results
·–
reveal that O2 and h+ are the dominant active species for the
photocatalytic degradation of RhB on the 0.2AgI/BMO photo-
catalyst.
Figure 8. (A) DRS spectra of BMO, AgI, and 0.2AgI/BMO, (B) plots of (αhν)1/2
versus the photon energy (hν) of the band-gap energy of BMO, AgI, and
0.2AgI/BMO.
Furthermore, the band-edge positions of AgI and BMO can
be estimated by the Mulliken electronegativity theory:[30] EVB
=
X – Ee + 0.5Eg and ECB = EVB – Eg, in which EVB is the valence-
band (VB) edge potential, ECB is the conduction-band (CB) edge
potential, X is the Mulliken electronegativity of the semicon-
ductor (ca. 5.55 and 5.48 eV for Bi2MoO6 and AgI, respec-
tively),[31,32] and Ee is the energy of a free electron on the
hydrogen scale (4.50 eV). From the equations and values ob-
tained above, EVB and ECB of Bi2MoO6 are calculated to be 2.35
and –0.25 eV, respectively. Similarly, EVB and ECB of AgI are esti-
mated to be 2.31 and –0.36 eV, respectively. The energy-band
structures of Bi2MoO6 and BiOI are illustrated schematically in
Scheme 1.
Figure 7. Active-species trapping experiments during the photocatalytic de-
composition of RhB on 0.2AgI/BMO.
The optical absorption properties of a semiconductor play
an important role in its photocatalytic performance. The UV/Vis
On the basis of the above results, a possible mechanism is
diffuse reflectance spectroscopy (DRS) spectra of AgI nanoparti- proposed to explain the enhancement of the photocatalytic ac-
cles, BMO microspheres, and the 0.2AgI/BMO heterojunction tivity of the AgI/BMO hierarchical heterostructure. In this sys-
are shown in Figure 8A. For pure BMO, the absorption spectrum tem, as shown in Scheme 2, the AgI/BMO composite presents
presents photoabsorption ability from the UV region to visible the morphology with AgI nanoparticles attached homogene-
light below 510 nm owing to the intrinsic band-gap transition. ously onto the surface of hierarchical flowerlike Bi2MoO6 mic-
In addition to the UV range, AgI displays strong absorption in rospheres. The whole process of the generation, transportation,
the region from λ = 400 to 460 nm. For 0.2AgI/BMO with AgI and reactions of photoinduced charge carriers in the AgI/BMO
nanoparticles loaded on the surface of BMO microspheres, the heterojunction is shown in Scheme 1. Upon irradiation by light
Eur. J. Inorg. Chem. 2016, 826–831
www.eurjic.org
829
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
enhancement of the photocatalytic activity of the AgI/BMO
heterojunction is attributed not only to the improvement in
visible-light harvesting but also to the effective separation of
·–
the photogenerated electrons and holes. In addition, O2 and
h+ are the dominant active species in the photocatalytic degra-
dation of organic compounds. Therefore, the AgI/Bi2MoO6 pho-
tocatalysts are potential candidates for practical applications in
photocatalysis. Additionally, the preparation strategy for the
AgI/BMO composite is expected to be extended to the synthe-
sis of other visible-light-driven heterostructured photocatalysts.
Experimental Section
All reagents were of analytical grade and used without further puri-
fication. Hierarchical Bi2MoO6 microspheres were synthesized by a
solvothermal process according to our previous report.[33] Briefly,
Bi(NO3)3·5H2O (3.638 g) and (NH4)6Mo7O24·4H2O (0.6636 g) were
dissolved completely in ethylene glycol (30 mL) by ultrasonication.
Then, absolute ethanol (90 mL) was added to the solution. The
mixture was stirred for 30 min and then transferred into a 150 mL
Teflon-lined stainless-steel autoclave and heated in an oven at
140 °C for 20 h. After the mixture had naturally cooled to room
Scheme 1. Schematic diagram of the energy-band structures of AgI and BMO
as well as the possible charge-transfer process under visible-light irradiation.
with λ > 400 nm, both AgI and Bi2MoO6 can be activated; this
causes the transfer of electrons from the valence band (VB) to
the conduction band (CB). Thus, holes (h+) and free electrons
(e–) are generated in the VB and CB, respectively. As displayed
in Scheme 1, as the ECB of AgI is more negative than that of
Bi2MoO6 and the EVB of Bi2MoO6 is more positive than that of temperature, the resultant grayish solids were collected by filtration
and washed several times with deionized water and ethanol and
then dried at 60 °C for 8 h. Finally, the powder was annealed at
400 °C for 90 min to remove the residues of organic contaminants
adsorbed on the surface.
AgI, at the interfaces between AgI and Bi2MoO6, the photogen-
erated electrons in AgI can move to the CB of the Bi2MoO6,
whereas the holes in Bi2MoO6 can transfer to the VB of AgI. As
a result, the separation of photogenerated electrons and holes
is enhanced in the AgI and Bi2MoO6; thus, the photocatalytic
performance is improved. The reduction of dissolved O2 can
The AgI/Bi2MoO6 heterostructured composites were prepared by a
deposition/precipitation method. In brief, a certain amount of the
as-synthesized Bi2MoO6, KI, and polyvinyl pyrrolidone (PVP) K30
aqueous solution (1 mL, 2.5 g/L) were added to deionized water
(25 mL). The mixture was stirred vigorously for 1 h to allow the I–
ions to be sufficiently absorbed on the surfaces of the Bi2MoO6
microspheres. Subsequently, AgNO3 (1 equiv. based on KI) was dis-
solved in deionized water (15 mL) with stirring. The AgNO3 solution
was added dropwise into the above mixture under magnetic stir-
ring, and the resultant suspension was stirred in the dark at room
temperature for 2 h. The AgI/Bi2MoO6 samples with different mass
fractions of AgI (10, 20, and 30 %) were named as 0.1AgI/BMO,
0.2AgI/BMO, and 0.3AgI/BMO, respectively. For comparison, pure
Bi2MoO6 (BMO), AgI, and mechanically mixed AgI/BMO with 20 wt.-
% AgI were also prepared. The latter was denoted as M-0.2AgI/BMO.
·–
produce O2·–. Finally, the organic pollutants are oxidized by O2
and h+ to form small molecules such as CO2 and H2O.
Scheme 2. Schematic diagram of the morphology of the AgI/BMO composite.
In short, by coupling AgI with Bi2MoO6, the heterostructured
photocatalyst displays a wide visible-light absorption range and
retards the recombination rate of photogenerated charge carri-
ers. Additionally, the AgI/BMO heterojunction also exhibits a
larger surface area than those of pure AgI or Bi2MoO6. There-
fore, the AgI/BMO photocatalyst is believed to exhibit coopera-
tive or synergic effects between the AgI and the Bi2MoO6 and
exhibits higher photocatalytic activity compared with those of
the single semiconductors AgI and Bi2MoO6.
The crystal structures and phase compositions of the prepared sam-
ples were characterized by XRD with an X'Pert PRO MRD diffractom-
eter with Cu-Kα radiation (0.154 nm). The morphologies of the sam-
ples were observed by SEM (JEOL JSM-6380-LA) and TEM (Tecnai
G220, FEI). The Brunauer–Emmett–Teller (BET) specific surface areas
of the samples were measured with a Quantochrome NOVA 1200e
instrument at 77 K. The optical properties were investigated by UV/
Vis DRS (Hitachi U-3010) with BaSO4 as a reference.
The photocatalytic activities of the as-prepared samples were evalu-
ated for the decomposition of RhB and BPA under visible-light irra-
diation at ambient temperature. During the degradation process, a
300 W tungsten halide lamp (Foshan Electric Light Ltd., Foshan,
China) was adopted as the simulated solar-light source and
equipped with a 400 nm cutoff filter to provide visible light (λ >
400 nm). In a typical photocatalytic reaction, the photocatalyst
(0.100 g) was added into RhB (8.0 mg/L) or BPA (15.0 mg/L) aqueous
solution (100 mL). Cooling water was passed through the outer
layer of the photocatalytic reactor to ensure that the reaction was
Conclusions
AgI/Bi2MoO6 heterostructured photocatalysts were successfully
prepared by a facile deposition/precipitation method. The pre-
pared AgI/BMO photocatalysts exhibited excellent visible-light
catalytic activities, and the optimal activity was achieved with
20 wt.-% AgI. Moreover, the catalyst maintains good reusability
and high stability in the photodecomposition of organics. The conducted at room temperature. The distance between the liquid
Eur. J. Inorg. Chem. 2016, 826–831
www.eurjic.org
830 © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
[12] C. H. An, W. Jiang, J. Z. Wang, S. T. Wang, Z. H. Ma, Y. P. Li, Dalton Trans.
2013, 42, 8796–8801.
[13] Y. Xu, W. D. Zhang, Sci. Adv. Mater. 2014, 6, 2611–2617.
[14] S. Z. Wu, K. Li, W. D. Zhang, Appl. Surf. Sci. 2015, 324, 324–331.
[15] J. X. Sun, Y. P. Yuan, L. G. Qiu, X. Jiang, A. J. Xie, Y. H. Shen, J. F. Zhu,
Dalton Trans. 2012, 41, 6756–6763.
[16] J. W. Tang, Z. G. Zou, J. H. Ye, J. Phys. Chem. C 2007, 111, 12779–12785.
[17] Y. Shimodaira, H. Kato, H. Kobayashi, A. Kudo, J. Phys. Chem. B 2006, 110,
17790–17797.
surface of the suspension and the light source was 20 cm. Before
illumination, the suspension was stirred magnetically in the dark for
1 h to reach the adsorption/desorption equilibrium on the surface
of the catalyst. At given time intervals, an aliquot of the suspension
(4 mL) was taken for analysis after centrifugation at 10000 rpm (2 ×
2 min). The concentration of the remaining RhB and BPA in the
solution was determined with a UV-3010 spectrophotometer at λ =
553 and 276 nm, respectively.
[18] Y. S. Xu, W. D. Zhang, Dalton Trans. 2013, 42, 1094–1101.
[19] B. Yuan, C. H. Wang, Y. Qi, X. L. Song, K. Mu, P. Guo, L. T. Meng, H. M. Xi,
Colloids Surf. A 2013, 425, 99–107.
Acknowledgments
[20] G. H. Tian, Y. J. Chen, J. Zhou, C. G. Tian, R. Li, C. J. Wang, H. G. Fu,
CrystEngComm 2014, 16, 842–849.
The authors thank the Guangdong Natural Science Foundation
(no. 2014A030311039) for financial support.
[21] X. Xiao, W. D. Zhang, J. Mater. Chem. 2010, 20, 5866–5870.
[22] P. Zhang, C. L. Shao, M. Y. Zhang, Z. C. Guo, J. B. Mu, Z. Y. Zhang, X.
Zhang, Y. C. Li, J. Hazard. Mater. 2012, 217–218, 422–428.
[23] B. G. Chen, Y. Y. Deng, H. X. Tong, J. H. Ma, Superlattices Microstruct. 2014,
69, 194–203.
Keywords: Bismuth · Silver · Photochemistry ·
[24] X. J. Wang, X. L. Wan, X. N. Xu, X. N. Chen, Appl. Surf. Sci. 2014, 321, 10–
18.
Heterostructures · Semiconductors
[25] N. Li, L. Zhu, W. D. Zhang, Y. X. Yu, M. F. Hou, J. Alloys Compd. 2011, 509,
9770–9775.
[26] X. Xiao, R. Hao, M. Liang, X. X. Zuo, J. M. Nan, L. S. Li, W. D. Zhang, J.
Hazard. Mater. 2012, 233, 122–130.
[1] R. Asahi, T. Morikawa, T. Ohwaki, K. Aoki, Y. Taga, Science 2001, 293, 269–
271.
[2] N. Serpone, A. V. Emeline, J. Phys. Chem. Lett. 2012, 3, 673–677.
[3] R. Daghrir, P. Drogui, D. Robert, Ind. Eng. Chem. Res. 2013, 52, 3581–3599.
[4] Y. S. Xu, W. D. Zhang, Appl. Catal. B 2013, 140–141, 306–316.
[5] M. Y. Zhang, C. L. Shao, J. B. Mu, Z. Y. Zhang, Z. C. Guo, P. Zhang, Y. C.
Liu, CrystEngComm 2012, 14, 605–612.
[27] M. A. Butler, J. Appl. Phys. 1977, 48, 1914–1919.
[28] Y. S. Xu, Y. X. Yu, W. D. Zhang, J. Nanosci. Nanotechnol. 2014, 14, 6800–
6808.
[29] H. F. Cheng, B. B. Huang, Y. Dai, X. Y. Qin, X. Y. Zhang, Langmuir 2010,
26, 6618–6624.
[6] N. Li, L. Zhu, W. D. Zhang, Y. X. Yu, W. H. Zhang, M. F. Hou, J. Alloys
Compd. 2011, 509, 9770–9775.
[30] X. Zhang, L. Z. Zhang, T. F. Xie, D. J. Wang, J. Phys. Chem. C 2009, 113,
7371–7378.
[31] H. P. Li, J. Y. Liu, W. G. Hou, N. Du, R. J. Zhang, X. T. Tao, Appl. Catal. B
2014, 160–161, 89–97.
[7] Q. S. Wu, Y. Feng, G. Y. Zhang, Y. Q. Sun, Y. Y. Xu, D. Z. Gao, Mater. Res.
Bull. 2014, 49, 440–447.
[32] C. L. Yu, L. F. Wei, W. Q. Zhou, J. C. Chen, Q. Z. Fan, H. Liu, Appl. Surf. Sci.
[8] J. Di, J. X. Xia, S. Yin, H. Xu, L. Xu, Y. G. Xu, M. Q. He, H. Li, J. Mater. Chem.
A 2014, 2, 5340–5351.
2014, 319, 312–318.
[33] L. Zhu, W. D. Zhang, C. H. Chen, B. Xu, M. F. Hou, J. Nanosci. Nanotechnol.
2011, 11, 4948–4956.
[9] H. M. Fan, H. Y. Li, B. K. Liu, Y. C. Lu, T. F. Xie, D. J. Wang, ACS Appl. Mater.
Interfaces 2012, 4, 4853–4857.
[10] Y. H. Liang, S. L. Lin, L. Liu, J. S. Hu, W. Q. Cui, Appl. Catal. B 2015, 164,
192–203.
Received: November 1, 2015
[11] R. F. Dong, B. Z. Tian, J. L. Zhang, Catal. Commun. 2013, 38, 16–20.
Published Online: January 20, 2016
Eur. J. Inorg. Chem. 2016, 826–831
www.eurjic.org
831
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim