Fabrication of molybdenum-substituted tungstophosphoric acid immobilized onto functionalized graphene oxide: Visible light-induced photocatalyst for selective oxidation of sulfides to sulfoxides

Article abstract of DOI:10.1016/j.inoche.2020.108353

Three set of molybdenum-substituted tungstophosphoric acid (H₃PW_12-yMo_yO₄₀ and y = 0, 6 and 12) was supported onto ethylene diamin functionalized magnetic graphene oxide (EDMG) and used to catalyze the selective

Full text of DOI:10.1016/j.inoche.2020.108353

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Short communication
Fabrication of molybdenum-substituted tungstophosphoric acid immobilized
onto functionalized graphene oxide: Visible light-induced photocatalyst for
selective oxidation of sulfides to sulfoxides
Hanieh Fakhri, Alireza Mahjoub, Razieh Nejat, Anasheh Maridiroosi
PII:
S1387-7003(20)30943-6
DOI:
https://doi.org/10.1016/j.inoche.2020.108353
INOCHE 108353
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Inorganic Chemistry Communications
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14 November 2020
17 November 2020
Please cite this article as: H. Fakhri, A. Mahjoub, R. Nejat, A. Maridiroosi, Fabrication of molybdenum-
substituted tungstophosphoric acid immobilized onto functionalized graphene oxide: Visible light-induced
photocatalyst for selective oxidation of sulfides to sulfoxides, Inorganic Chemistry Communications (2020), doi:
https://doi.org/10.1016/j.inoche.2020.108353
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Fabrication of molybdenum-substituted tungstophosphoric acid immobilized
onto functionalized graphene oxide: Visible light-induced photocatalyst for
selective oxidation of sulfides to sulfoxides
Hanieh Fakhri1, Alireza Mahjoub1, *, Razieh Nejat2, *, Anasheh Maridiroosi1
1Department of Chemistry, Tarbiat Modares University, P.O. Box 14155-
4383, Tehran, Iran
2Chemistry Department, Faculty of science, Kosar University of Bojnord,
Iran. Bojnord, Iran
Corresponding author: Ali Reza Mahjoub, Razieh Nejat
E-mail address: Mahjouba@modares.ac.ir, organochem_nejat@yahoo.com.
First author: Hanieh Fakhri
E-mail address: hanieh_fakhrie@yahoo.com
Tel.: (+98) 21 82883442, (+98)-58-32427408

Abstract
Three set of molybdenum-substituted tungstophosphoric acid (H3PW12-yMoyO40 and y=0, 6
and 12) was supported onto ethylene diamin functionalized magnetic graphene oxide
(EDMG) and used to catalyze the selective oxidation of sulfides to sulfoxides under visible
light illumination. It was found that Mo cations in the heteropoly acids (HPAs) structure has an
important role in this photocatalysis system where the catalytic performance of samples was
enhanced with increasing the molybdenum substitution content from y= 0 to 12. Noteworthy, this
improved efficiency originated from noticeable synergetic effects between HPAs and graphene
oxide layers, expanded responsivity to visible light, faster migration of photoinduced electrons on
graphene oxide layers and also high power oxidation of this photocatalyst. Aided by
magnetic nature of nanocomposite, separation process at the end of the reaction was easily
done by external magnet. Furthermore, the optimum photocatalyst displays acceptable
reusability after subsequent 10 runs. High yield, low reaction time and non-toxicity of the
catalyst were indicated that H3PMo6W6O40@ethylene diamin functionalized magnetic
graphene oxide is a promising catalyst for direct photocatalyst applications.
Keywords: Photocatalyst; Oxidation of sulfides, Heteropoly acid, Graphene oxide.

1. Introduction
Oxidation is one type of the most important reactions in order to prepare the oxygenated
products that are useful as platform commodities and specialty chemicals [1-4]. In this regard, the
selective oxidation of sulfides to sulfoxides is yet challenging transformations in organic reactions
with a remarkably wide scope in biologically significant molecules such as anti-ulcer [5],
antibacterial [6], and antifungal and so on [7-11]. In the recent years, photocatalysis process had
an excellent resume in this organic synthesis [12-14]. However, this chemical transformation
procedure is very challenging to be employed by conventional semiconductor photocatalysis due
to wide band gap, low surface area and high recombination of charge carriers.
Various semiconductors, such as TiO2 [9, 15], ZnO [10, 16], metal organic frameworks
[11, 17], g-C3N4 nanaosheets and heteropoly acids (HPAs) [18-21], have been investigated for
this oxidation reactions. Among these compounds, HPAs show superior efficiency due to their
high stability, favorable reversibility in multi-electron redox reaction and unique structure [22-25].
Their major photocatalytic mechanism is similar cycle to metal oxide semiconductors as after
adsorbing light, HPAs will be excited to produce electron-hole pairs. Then, these charge carriers
can initiate reductive-oxidative reactions [26]. The keggin type HPAs compounds are the well-
defined metal-oxygen clusters that formulated as H+ [XM12O40]n-, it is noteworthy that their
n
catalytic behavior can be altered by varying the nature and number of X as heteroatom, M as
addenda atom, and H as counter cation. For example, chamack et al. [23] presented that the
exchange of W with Mo in the phosphomolybdic acid lead to improvement desulfurization
efficiency. In the other study [27], different efficiencies were obtained by using a category of
vanadium-substituted molybdophosphoric acids (PMo12−nVn, n = 1–3). These catalysts were used
to catalyze the liquid phase oxygenation of cyclohexane by N2O in acetonitrile (MeCN).

However, high recombination rate of charge carriers and high solubility in polar media have
restricted their vast application [28]. There are various strategies to improve their properties and
efficiency [29-31]. Nevertheless, only a few of them have led to the design of a stable and effective
system and usually problems such as high leaching and inactivation of active sites limit their
performance. Therefore, designing a well-functionalized photocatalyst is a challenge for active
scientists in the field yet.
Recent studies have shown that immobilization of HPAs on carbon substrates has
dramatically increased their photocatalytic ability [32, 33]. Graphene oxide (GO) as the member
of this family can be a suitable candidate for anchoring of HPAs, stemming from the layered
structure, the presence of diverse functional groups, and its high surface area. In addition, GO can
act as an acceptor component of photoinduced electrons of HPAs and reduce the charge
recombination, also it with planar structure and high conductivity can enhance transporting
behavior of nanocomposites. Nevertheless, leaching of HPAs from support surface is problem that
should be solved. In this regards, ethylenediamine was grafted on GO and thus numerous sites of
amine groups supply on the surface of GO. Moreover, this support can also modify by magnetic
nanoparticles like Fe3O4 to form a magnetic photocatalyst with more economic and easier filtration
system than conventional methods.
In this work, we present three novel set oxidation systems based on molybdenum-
substituted tungstophosphoric acids (H3PW12-yMoyO40 and y=0, 6 and 12) containing
H3PW12O40@ethylenediamine functionalized magnetic graphene oxide (W12@EDMG),
H3PMo6W6O40@ethylenediamine functionalized magnetic graphene oxide (Mo6W6@EDMG) and
H3PMo12O40@ethylenediamine functionalized magnetic graphene oxide (Mo12@EDMG). These
photocatalysts were fully characterized and for the first time, their ability was reported in selective

oxidation of sulfides to sulfoxides reactions under visible light illumination. This study can open
windows to fabrication of new class of HPAs photocatalyst in organic synthesis.
2. Experimental
2.1. Materials
All purchased solvents and chemicals were of analytical grade and used without further
purification. Materials containing graphite, 3,3'-diaminobenzidine (DAB), potassium
permanganate (KMnO4), sulfuric acid (H2SO4), hydrochloric acid (HCL), Ethylenediamine (ED),
ethylene glycol, 3-Aminopropyl triethoxysilane (APTES), tungstophosphoric acid (W12),
molybdophosphoric acid (Mo12) and ethanol were supplied from Merck and Sigma-Aldrich
companies and used any purification.
2.2. Preparation of magnetic graphene oxide (MG)
Graphene oxide (GO) was synthesized through modified Hummers method [32]. To preparation
of Fe3O4 [34], firstly, FeCl3·6H2O (1.2 g) and polyethylene glycol (1g) were dissolved in 50 ml
ethylene glycol and then NaAc·3H2O (3.3 g) was added to it. After 30 min stirring, the final
mixture was moved to an autoclave and placed at 200 ˚C for 8 hour. The collected black powder
was washed and dried at 60 ˚C for 12 hour. In following, for preparation of magnetic graphene
oxide (MG), the mixture of solvent containing 60 mL water and 40 mL ethanol were prepared and
then 2 g of GO was dispersed in this solvent. After 30 minute sonication, 1 g Fe3O4 was added to
above suspension and stirred for 1 hour. Next, this suspension was moved into an autoclaves and
kept at temperature 200 ˚C for 12 hour. Finally, it was separated by using magnet and washed with
water for three times.
2.3. Preparation of ED functionalized MG (EDMG)

For preparation of ED functionalized MG, 0.3 g of MG was suspended in the mixture containing
20 mL ethylene glycol and 40 mL ED and sonicated for 30 minute. Next, this mixture was placed
into a teflon-lined autoclave and heated at 200 ̊C for 12 hour. After cooling, the powder was filtered
and washed by ethanol and dionized water. Finally, the prepared sample was dried in at 70
12 hour [28]. This product was nominated as EDMG.
̊C for
2.4. Preparation of H3PMo6W6O40@EDMG (Mo6W6@EDMG)
H3PMo6W6O40 (Mo6W6) nanoparticles were prepared according to reported reference [35]. For the
synthesis of Mo6W6@EDMG, 0.4 g EDMG was sonicated in 20 mL ethanol for 30 minute. Then,
0.8 g of Mo6W6 was added to it, sealed and stirred for 24 hour. Afterwards, the cap was removed
and the solid phase was filtered. Subsequently, it was dried at 70
preparation are illustrated in Scheme 1.
̊C. The steps of the photocatalyst

Scheme 1. Schematic representation of the synthesis of magnetic Mo6W6@EDMG
nanocomposites
The similar process was used to preparation of H3PW12O40@EDMG (W12@EDMG) and
H3PMo12O40@EDMG (Mo12@EDMG).
2.5. General procedure for the oxidation of sulfides to sulfoxides
A mixture of sulfide (1 mmol), H2O2 33% (0.5 mL), ethanol as solvent (10 mL) and
Mo6W6@EDMG (0.005 g) as catalyst was added to a Pyrex flask. The mixture was stirred
under visible light irradiation (a 400 W lamp, high-pressure mercury-vapor lamp with UV filter
(Oriel, 51472) was used as a visible light irradiation source) for the required time to complete the
reaction. When the reaction was completed, the catalyst separated. The product was
extracted with CH2Cl2, washed with water (6 mL) and evaporated the solvent to give the
corresponding pure sulfoxide.
2.6. Characterization
The phase purity and crystalline structure of samples were analyzed by using Philips X-pert X-ray
diffractometer using Cu Kα radiation (wavelength, λ= 1.5418 ˚A). The FT-IR spectra were
recorded by using Fourier transform infrared (FT-IR) spectrometer on Thermo Scientific Nicolet
IR100 (Madison, WI). The UV-vis curves (UV-vis) were obtained using Shimadzu UV-2550-8030
spectrophotometer. Transmission electron microscopy (TEM) analysis was recorded on Philips
EM208S 100KV. Scanning electron microscopy (SEM) equipped by energy despersive X ray-
spectroscopy
(EDX)
analysis
was
utilized
to
assay
the
morphology using a Philips XL-300 instrument.
3. Results and discussion

3.1. Characterization of the catalyst
The phase purity and crystallinity of samples were assayed by using XRD analysis (Fig. 1A). In
the GO pattern (Fig. 1a), the diffraction peaks at 2ϴ=11
oxidized graphite layer and partial reduction of GO respectively [19, 28, 36]. After introducing of
ED functional groups and magnetic particles to GO (Fig. 1b), the peaks at 34.9 , 41.2 , 45.9 , 62.8
, 68.4 and 74.5 were observed that referred to the inverse spinel crystalline phase of Fe3O4 with
̊ and 26̊ are referred to (002) plane of
̊
̊
̊
̊
̊
cubic symmetry [37, 38]. However, reduced intensity of GO diffraction was observed that can be
due to its low crystallinity. However, no peaks belong to HPAs were detected When HPAs anchor
to surface of supports (Fig. 1c, d and e) that is due to its high dispersion of HPAs on the EDMG
support [28].
Fig. 1. A: XRD pattern of (a)GO, (b) EDMG, (c) W12@EDMG, (d) Mo6W6@EDMG and (e)
Mo12@EDMG; B: FT-IR spectra of (a’) GO, (b’) EDMG, (c’) W12@EDMG (d’)
Mo6W6@EDMG, (e’) Mo12@EDMG
For more precise investigation of the samples as well as the interactions that exist, the FT-IR
spectroscopy was used (Fig. 1B). The main characteristic bands belong to GO were located at
1712 cm-1, 1622 cm-1 and 1000-1300 cm-1 which attributed to C=O, C=C and C-O stretching

vibrations respectively (Fig. 1a׳) . In the spectrum of EDMG (Fig. 1b׳), the observed bands at 3335
cm-1 and 1479 cm-1 are assigned to O-H stretching vibration and C-N stretching vibration
respectively [28, 39], also the vibration of Fe-O stretching vibration was assigned at 450-480
cm-1 that referred to magnetic particles in nanocomposite structure [38]. In the Fig. 1c’, d’ and e’,
the chief peaks of HPAs located at 1060–1080 cm−1 (ν P-O), 967–978 cm−1 (ν metal=O), 870–880 cm−1
( ν metal-O-metal) and 770–780 cm−1 (ν metal-O-metal) were observed [35]. As seen, after introducing of
these HPAs to support, EDMG bands are well detectable.
The SEM images of products were presented in Fig. 2. For Fe3O4 sample, the spherical morphology
with size of 300-400 nm were observed in Fig. 2a. Fig. 2b indicates GO with layer structure which
in some areas, it has wavy or pleated morphology. As seen in Fig. 2c, the smooth layers of GO
were covered by HPAs sample that have particle morphologies. In the image of Mo6W6@EDMG,
the simultaneous presence of components confirmed the successful synthesis of nanocomposite.
Furthermore, TEM image of Mo6W6@EDMG revealed proper connection between components
and verified that there is not an agglomeration that can be blessing from sonication during synthesis
procedure.

Fig. 2. SEM images of (a) Fe3O4, (b) GO, (c) Mo6W6@EDMG and (d) TEM image of
Mo6W6@EDMG
For deeper evaluation, EDX analysis was used. The Mo and W peaks were appeared in the EDX
spectrum (Fig. 3). Furthermore, the Fe peak that originated from magnetic cores, was observed.
The peaks belong to C, N and O are also seen that attributed to organic components in this
nanocomposite. Besides, the elemental mapping images (Fig. 4) revealed the larger cores are cores
of Fe3O4 and small particles that supported on EDMG, are Mo6W6 nanoparticle. As seen, no
impurity related peak is observed which verify previous analyzes.

Fig. 3. EDX spectrum of Mo6W6@EDMG
Fig. 4. Original image of the region where the mapping was performed (a); Element mapping
images of Tungsten (b); Molybdenum (c); Iron (d); Nitrogen (e); Carbon (f);
Oxygen (g)
The N2 adsorption–desorption technique represented information about the textural properties. All
of the isotherms are belong to IV type isotherm, according to IUPAC were assigned to mesoporous
materials. BET surface areas and pore size are tabulated in Table 1. As seen (Fig. 5), the BET

surface area of Mo6W6 sample is a low value and it increases after anchoring to EDMG. This can
be ideal in photocatalytic system.
Fig. 5. N2 adsorption–desorption isotherm from samples
Table1. BET surface area and average pore size of photocatalysts
Photocatalyst
EDMG
BET surface area (m2.g-1)
Average pore size (A ̊)
9.87
12.79
19.59
14.55
19.96
-
Mo6W6
3.74
W12@EDMG
Mo6W6@EDMG
Mo12@EDMG
10.27
12.11
10.52
3.2. Oxidation reaction of sulfides to the sulfoxides in the presence of Mo6W6@EDMG

Preliminary, the catalyst effect on the oxidation of thioanisole (1a) as the model substrate was
investigated. Various conditions on the yield were studied using visible light irradiation, reaction
temperature, catalyst loading, various catalysts, oxidants and solvents (Table 2).
a
Table 2. Optimization for the oxidative reaction 1a with H2O2
O
S
,
Catalyst hv, oxidant
S
Solvent, 25/35 °C,
1b
1a
Entry
Catalyst
Catalyst Solvent Visible‐light oxidant Time Yieldb
amount
(g)
irradiation
(min)
(%)
1
2
3
Mo6W6@EDMG
Mo6W6@EDMG
Mo6W6@EDMG
-
EtOH
EtOH
EtOH
400 W lamp
-
H2O2
H2O2
H2O2
120
120
120
-
35
87
0.005
0.005
400 W lamp
4
5
W12@EDMG
Mo12@EDMG
0.005
0.005
0.005
0.003
0.007
0.005
0.005
0.005
0.005
EtOH
EtOH
EtOH
EtOH
EtOH
DMSO
CH3CN
DMF
400 W lamp
400 W lamp
400 W lamp
400 W lamp
400 W lamp
400 W lamp
400 W lamp
400 W lamp
400 W lamp
120
120
120
120
120
120
120
120
120
76
80
27
60
88
10
25
20
30
H2O2
H2O2
air
6
Mo6W6@EDMG
Mo6W6@EDMG
Mo6W6@EDMG
Mo6W6@EDMG
Mo6W6@EDMG
Mo6W6@EDMG
Mo6W6@EDMG
7
H2O2
H2O2
H2O2
H2O2
H2O2
H2O2
8
9
10
11
12
H2O
aReaction conditions: 1 mmol of 1a, 1.5 mmol of H2O2, catalyst. bIsolated yield.
It was found that the reaction did not proceed without a catalyst (entry 1) and the catalytic activity
of Mo6W6@EDMG was higher than W12@EDMG and Mo12@EDMG (entries 4 and 5). Also, the
use of air as oxidant gave lower yields than H2O2 (entry 6). A decrease in the amount of catalyst

leads to a decrease in yield (entry 7). Next, the effect of light irradiation for the reaction was studied
and it was noticed that, the reaction worked out best under visible light irradiation (entry 2). The
reaction produces the best yield under visible-light irradiation in EtOH using 0.005 g of catalyst
and H2O2 as oxidant. To explore the scope, the optimized conditions is extended to a variety of
sulfides (Table 3).
Table 3. Oxidation of sulfides to the sulfoxides in the presence of Mo6W6@EDMG a
O
Mo6W6@EDMG,
hv
S
S
R1
EtOH, 25-35 °C,
H2O2 (33 %)
R2
R1
R2
1b-13b
1a-13a
Entry
Substrate Product
1a-13a
Substrate Product
Time (min) Yieldb(%)
1b-13b
O
S
S
1
2
90
95
65
S
O
S
180
O
S
S
3
4
120
110
87
83
O
S
S
Cl
Cl
S
O
S
Br
5
6
100
125
85
75
Br
O
S
S
NO2
NO2
7
8
130
180
90
60
S
S
O
O
S
S
Br
Br
S
S
O
9
30
70
88
90
O
S
S
10

S
S
11
12
90
60
87
90
O
O
S
OMe
S
OMe
O
O
O
S
S
13
100
92
aAll reactions were carried out using 1-13 (1 mmol) and 0.005 gr of catalyst in 10 mL
of ethanol under visible light irradiation. bIsolated yields.
Under visible light illumination, the electron-hole pairs were produced. According to the reported
researches [31, 40], composite of HPAs with other metal oxides creates additional energetic levels
in the band gap of HPAs, resulted in the decrease of the energy barrier and increase visible light
absorption capacity (Scheme. 2). These phenomenon was checked by UV-vis analysis. The first
derivative of the absorption spectrum was employed for assessing the absorption edge wavelength
of suspension containing metal oxide [41-43]. Then, the band gap of a semiconductor can be
determined using the below relation:
Eg=hc/λred
Eq.1
where h is the Planck's constant, с is speed of light and λred is edge of absorption. As seen (Fig. 6),
the adsorption edge of Mo6W6 has located at 353 nm (Eg= 3.4 eV) and it shifted to visible region
at 442 nm (Eg= 2.8 eV). This shift is desirable in photocatalytic system because of visible light
contains more than 40% solar spectrum, while UV area contains less than 5% of the solar spectrum.
In the other hand, in this design, GO can acts as an electron acceptor and decrease recombination
of photo- induced charge carriers the electron hole. Also, its planar structure enhances transporting
behavior of nanocomposites. Finally, the sum of these factors lead to improved performance.

Fig. 6. UV-Vis curves of Mo6W6 and Mo6W6@EDMG
In order to investigate photocatalytic 1O2 generation, 10 mg 3,3'-diaminobenzidine (DAB) and 2
mg photocatalyst were dissolved in 5 mL aqueous solution and this was diluted 10 times.
Afterwards, two types of light sources including a lightemitting diode (LED) at a wavelength of
365 nm and sunlight were used to irradiation. Singlet oxygen (1O2) is an active agent that
generally utilized in environmental purification, catalysis, photodynamic therapy (PDT) for
cancer treatment and etc. The 1O2 generation by Mo6W6@EDMG was investigated by using two
types of light sources including laser at 365 nm and sunlight, and then were assayed by chemical
probe detection. As seen (Fig. 7), the UV absorption spectrum of chemical probe DAB slowly
decreased to zero after 25 min under the irradiation of 365 nm laser, representing that DAB
transformed to 3,3'-dinitrobenzidine in the presence of generated 1O2 species [44,45]. It is be
noted that DAB cannot react with 3O2. The UV also was reduced after 20 min under sunlight
irradiation. According to these results, it can propose that under light irradiation, the light excited

photoelectron can moved to the triplet state and finally generate to the 1O2 species through
energy transfer from the Mo6W6@EDMG to 3O2.
Fig. 7. UV-vis spectra of DAB in an aqueous solution of Mo6W6@EDMG
cluster under (a) 365 nm laser and (b) sunlight irradiation in air
Since the reuse of the catalyst in the industry is important parameter, the reusability tests of
photocatalyst were investigated for the oxidation of sulfides to the sulfoxides under optimized
conditions. After separating the catalyst by external magnetic from the reaction, it was reused for
10 runs in the oxidation of sulfides. As evident from Fig. 8, the recovered catalyst was recycled in
subsequent runs without observation of a significant decrease in activity even after the tenth run.

Fig. 8. Reusability of Mo6W6@EDMG for the oxidation of thioanisole
Conclusions
The selective photocatalytic oxidation of sulfides is greatly valuable for current organic and
pharmaceutical synthesis. Therefore, there is an immediate demand for tracking efficient
photocatalytic system on this reaction. As visible light induced photocatalyst, three type of
molybdonum-substituted tungstophosphoric acids, H3PW12-yMoyO40 and y=0, 6 and 12, were
successfully immobilized onto ethylenediamine functionalized magnetic graphene oxide (EDMG).
Under optimized situations, the best efficiency was obtained by using H3PMo6W6O40@EDMG
(indicated as Mo6W6@EDMG) that corresponded to higher power oxidation in compared with
other used photocatalysts. Furthermore, the used design in preparation of nanocomposite leads to
high adsorption of visible light and fast transmittance of electrons which have synergistic effects.
It is worthy to mention, this is the first display of a mild and high-efficiency procedure for the
selective sulfoxidatons by this functionalized heteropoly acid based photocatalyst.

Scheme 2. Mechanism of Mo6W6@EDMG for the visible-light activity photocatalyst
Acknowledgements
The financial support of this work, by Tarbiat Modares University, Kosar University of Bojnord
and Iranian Nanotechnology Initiative, is gratefully acknowledged.
Figure Caption
Fig. 1. A: XRD pattern of (a)GO, (b) EDMG, (c) W12@EDMG, (d) Mo6W6@EDMG and (e)
Mo6W6@EDMG; B: FT-IR spectra of (a’) GO, (b’) EDMG, (c’) W12@EDMG (d’)
Mo6W6@EDMG, (e’) Mo6W6@EDMG.
Fig. 2. SEM images of (a) Fe3O4, (b) GO, (c) Mo6W6@EDMG and (d) TEM image of
Mo6W6@EDMG
Fig. 3. EDX spectrum of Mo6W6@EDMG
Fig. 4. Original image of the region where the mapping was performed (a); Element mapping
images of Tungsten (b); Molybdenum (c); Iron (d); Nitrogen (e); Carbon (f); Oxygen (g)
Fig. 5. N2 adsorption–desorption isotherm from samples
Fig. 6. UV-Vis curves of Mo6W6 and Mo6W6@EDMG
Fig. 7. UV-vis spectra of DAB in an aqueous solution of Mo6W6@EDMGcluster under (a) 365
nm laser and (b) sunlight irradiation in air
Fig. 8. Reusability of Mo6W6@EDMG for the oxidation of thioanisole
Scheme 1. Schematic representation of the synthesis of magnetic Mo6W6@EDMG
nanocomposites
Scheme 2. Mechanism of Mo6W6@EDMG for the visible-light activity photocatalyst
Table1. BET surface area and average pore size of photocatalysts
a
Table 2. Optimization for the oxidative reaction 1a with H2O2
Table 3. Oxidation of sulfides to the sulfoxides in the presence of Mo6W6@EDMGa
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Highlights
 Designing three new set of visible-light driven photocatalyst based on
HPAs.

Proving the promising role of Mo cations in selective aerobic oxidation
reactions
.
 Providing photoctalyst with more responsivity to visible light
 Fast transmittance of photoinduced electrons by using GO layer

Declaration of interests
No conflict of interest exists.
We confirm that there are no known conflicts of interest associated with this publication.
Ali Reza Mahjoub
Sincerely

Credit Author Statement
Hanieh Fakhri: Data curation, Material engineering, Methodology, Material characterization,
Writing-original draft. Alireza Mahjoub: Supervision, Visualization, Resources, review &
editing. Razieh Nejat: Instrumental analysis, Interpretation of the obtained data, Writing -
review & editing. Anasheh Maridiroosi: Material synthesis, Formal analysis, Investigation,
Sample preparation procedure.