Reduced graphene oxide-supported PbTiO3 nanospheres: Improved ceramic photocatalyst toward enriched photooxidation of thiophene by visible light

Article abstract of DOI:10.1016/j.mcat.2020.111301

Perovskite titanate-based nanostructures have got enough attraction for environmental remediation as active and stable photocatalysts. More, the removal of stable organic compounds such as thiophene (ThP) is of great importance in different industries. Here, we have synthesized PbTiO₃ nanospheres using a modified sol-gel method. The PbTiO₃ loaded on different amounts of reduced graphene oxide (rGO) to yield PbTiO₃@rGO nanocomposite. The improved PbTiO₃@rGO exhibited a complete photooxidation of ThP after 60 min of applying visible light with outstanding recyclability. The PbTiO₃@rGO nanocomposites demonstrated an enlargement in the visible light absorption with a reduction of its bandgap energy from 2.45 to 1.90 eV at 9 wt.% of rGO loading. Also, we noticed the decrease of electron-hole recombination rate by photoluminescence and photocurrent measurements as well. This work proves the applicability of using rGO supported perovskites structured photocatalysts for several environmental remediation-related purposes.

Full text of DOI:10.1016/j.mcat.2020.111301

Molecular Catalysis xxx (xxxx) xxx
Contents lists available at ScienceDirect
Molecular Catalysis
journal homepage: www.journals.elsevier.com/molecular-catalysis
Reduced graphene oxide-supported PbTiO nanospheres: Improved ceramic
3
photocatalyst toward enriched photooxidation of thiophene by visible light
a
b
,
c,
d
Maha Alhaddad , Ahmed Shawky *, Z.I. Zaki
a
Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80200, Jeddah 21589, Saudi Arabia
b
c
Nanomaterials and Nanotechnology Department, Advanced Materials Division, Central Metallurgical R&D Institute (CMRDI) P.O. Box 87, Helwan 11421, Cairo, Egypt
Department of Mechanical Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8565 Japan
Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
d
A R T I C L E I N F O
A B S T R A C T
Keywords:
Perovskite titanate-based nanostructures have got enough attraction for environmental remediation as active and
stable photocatalysts. More, the removal of stable organic compounds such as thiophene (ThP) is of great
Sol-gel synthesis
PbTiO
rGO
3
importance in different industries. Here, we have synthesized PbTiO
method. The PbTiO loaded on different amounts of reduced graphene oxide (rGO) to yield PbTiO
nanocomposite. The improved PbTiO @rGO exhibited a complete photooxidation of ThP after 60 min of
applying visible light with outstanding recyclability. The PbTiO @rGO nanocomposites demonstrated an
3
nanospheres using a modified sol-gel
3
3
@rGO
Photocatalysis
3
Thiophene remediation
3
enlargement in the visible light absorption with a reduction of its bandgap energy from 2.45 to 1.90 eV at 9 wt.%
of rGO loading. Also, we noticed the decrease of electron-hole recombination rate by photoluminescence and
photocurrent measurements as well. This work proves the applicability of using rGO supported perovskites
structured photocatalysts for several environmental remediation-related purposes.
1
. Introduction
The fast progress in technology by inducing innovative industries
research [12–14]. Generally, the use of nanostructured semiconductors,
as an advanced photooxidative desulfurizers for ThPs, implies an alter-
native and ecological compared to the other established methods [3,
consumes lots of fuels. Consequently, the contamination actions to the
whole atmosphere developed rapidly. The extensive use of traditional
15–20]. Amid those, the perovskite titanates (PrTs), which have ATiO
3
form, are promising candidates in photocatalytic conversion and elim-
ination of relatively stable organics [21–23]. This possibility is due to
the structure flexibility, chemical stability, and more straightforward
x x
fuel generates emergent toxins and gases like NO and SO those are
intensifying exponentially with time [1,2]. Thiophene (ThP) is a broad
evolved sulfur-containing substance that mainly present in gasoline [3,
synthesis process [24–26]. However, most PrTs, such as CaTiO
3 3
, LaTiO ,
4
]. Furthermore, ThP complexes spinoffs are frequently employed in
several industrial purposes, including photovoltaic cells [5], electronics
6], medicinal [7], and drug manufacturing [8]. The infinite consump-
and SrTiO , have large bandgap energies (E ) values and suffer from
3
g
recombination of the photoinduced charge carriers [21,22,27]. So,
many attempts are carried out to tune their visible light response [24,28,
[
tion of ThPs is regarded to the chemical inertness of these amalgams.
The aromaticity of ThPs impedes the electron density surrounding the
sulfur atom. The chemical stability of ThP is the key for being applied in
most organic and biochemical applications. However, the toxic com-
plexes progressed in the environment as a result of ThPs consumption
rise a coming global pollution [9,10]. Accordingly, spectacular efforts
for clean industry and ecological remediation are constructing im-
provements regarding this issue [10,11]. Likewise, the valuation for
applied approaches to eradicate ThPs turn into crucial anxiety in present
29]. Amongst PrTs, PbTiO
that has relatively small E
3
(PTO) is a visible-light active photocatalyst
. A wet chemical process can synthesize the
g
PTO at high yield [30–33]. PTO also showed a promising performance
for the degradation of organic toxins in wastewater and hydrogen pro-
duction under visible light [29–31,34,35]. However, there are no studies
on photocatalytic applications using PTO as for ThP removal.
On the other hand, the use of two-dimensional reduced graphene
(rGO) can increase the photocatalytic activity of the PTO to overcome
the aggregation, improve carrier separation, and increase the visible
*
Corresponding author at: Nanomaterials and Nanotechnology Department, Advanced Materials Division, Central Metallurgical R&D Institute (CMRDI) P.O. Box
8
7, Helwan 11421, Cairo, Egypt.
E-mail address: phyashawky@cmrdi.sci.eg (A. Shawky).
https://doi.org/10.1016/j.mcat.2020.111301
Received 20 August 2020; Received in revised form 25 October 2020; Accepted 30 October 2020
468-8231/© 2020 Elsevier B.V. All rights reserved.
2
Please cite this article as: Maha Alhaddad, Molecular Catalysis, https://doi.org/10.1016/j.mcat.2020.111301

M. Alhaddad et al.
Molecular Catalysis xxx (xxxx) xxx
light absorption [32,36,37]. Presently, rGO displayed a significant
support to perovskite-based materials for enhancing their photoactive
properties [36,38,39]. Additionally, rGO bared some ability for deep
desulfurization of ThP [40]. As a consequence, a gathering of PTO and
rGO can boost the photooxidative desulfurization of ThP by improving
the surface possessions, photocharge mobility, and photoactivity as
well.
2.4. Characterizing the formed materials
The as-prepared nanostructures were considered by different
equipment. The Bruker X-ray diffractometer (axis D8, Cu K radiation)
α
identifies the crystalline phases. In contrast, X-ray photoelectron spec-
troscopy (XPS, Thermo Scientific) depicts the oxidation states and
chemical compositions through core-level spectra. HORIBA LabRAM
HR800 Raman spectrometer with 514.5 nm laser observes the produced
GO/rGO samples. For nanomorphological investigation, suspended
samples on carbon-coated grids were seen by JEOL-JEM-1230 Trans-
mission electron microscope (TEM) with high resolving power (200 kV)
to obtain the lattice fringes in the high resolution (HR) mode. The sur-
face texture analysis and surface area measurements, using Bru-
nauer–Emmett–Teller (BET), of the gained samples obtained by Nova
2000 Chromatech device at nitrogen atmosphere [43]. The Jasco V-570
spectrophotometer characterizes the light absorbance by the samples in
Herein, we firstly present a sol-gel preparation of PTO nanospheres
that successively loaded onto different rGO amounts to form PTO@rGO
nanocomposites by an easy process. The description of the assembled
nanostructures revealed the upsurging of surface texture, widening of
g
visible light absorbance, and minimizing of E of PTO by the introduc-
tion of rGO. The PTO@rGO photocatalyst displayed a total ThP photo-
oxidation in a relatively short time with exceptional reusability under
visible light radiation. The exceptional photocatalytic enactment of
PTO@rGO is credited to the suppression of photocharge separation and
mobility by the adjusted rGO content. This proposed photocatalyst will
rely on the application of PrT-based and rGO-supported photocatalysts
for the exclusion of stable sulfur-containing amalgams released from
fuels and related industries.
g
ambience. The E for each sample was calculated from the diffusive
reflectance (DR) by the Kubelka-Munk theory. The Shimadzu RF-5301
fluorescence spectrophotometer laboured for monitoring the photo-
luminescence (PL) spectra of the produced photocatalysts. Also,
Zennium-Zahner electrochemical system measures the transient photo-
current generated by the PTO, and PTO@x%rGO blended on ITO glass
applying ON-OFF states of the visible light. The photogenerated radical
species were detected by an electron spin resonance (ESR) spectrometer
2
. Materials and approaches
2
.1. Materials
(
Bruker EPR A300) in ambient conditions under light illumination.
The purchased chemicals were from Merck and were not followed
any further purifications. Titanium(IV) isopropoxide (TiISP, 99.99 %
trace metals basis), and Lead(II) acetate trihydrate (PbAc, ACS reagent,
2
.5. Photoactivity measurements by ThP oxidation
≥
99 %) were used for PTO growth. The triblock copolymer, namely
)CHO–, MW 12,600 g mol–1, Pluronic F-
A 50 mL of ThP mixed with acetonitrile, to get 600 ppm of sulfur
EO¼–CH CH O–PO¼–CH (CH
27, utilized to control the sol-gel size nanoreactors. ACS reagent sol-
vents and sol-gel mediators were ethyl alcohol (C
OH, ≥99.8 %),
hydrochloric acid (HCl, 37 %), glacial acetic acid (ACA, ≥99.7 %). The
carbon basis was graphite powder (flakes <45
m, ≥99.99 %). The
oxidizing negotiators were sulfuric acid (H SO , 99.999 %). Potassium
persulfate (K , ≥98.0 %),
, ≥99.0 %), Phosphorus pentoxide (P
Sodium nitrate (NaNO
, ≥99.0 %), and Potassium permanganate
2
2
2
3
content, was discharged into a quartz reactor under oxygen bubbling for
0 min. After that, a definite amount of the as-synthesized PTO@x%rGO
1
3
2 5
H
photocatalyst was slowly presented to it. The mixture spun in murky
condition for 1 h to settle the equilibrium condition. At that point, a 300
W Xe lamp providing light with wavelengths >420 nm exposed to the
reactor. The water circulator equipped to the reaction cell keeps the
μ
2
4
2
2
S O
8
2 5
O
◦
temperature at 25 ± 2 C. The reaction products were examined through
3
Agilent 7890 GC/GC–MS-FPD gas chromatograph with FFAP column.
The photooxidation efficiency (POD) of ThP by the PTO@x%rGO
appraised through relative concentrations as;
(
KMnO
4
, ≥99.0 %).
2
.2. Growth of PTO nanospheres
C
i
ꢀ C
t
POD (%) =
× 100
(1)
Momentarily, the sol-gel process starts by combining a 2.0 g of F-127,
.6 mL of ACA, and 0.65 mL of HCl in a beaker having 40 mL of C OH.
C
i
5
2 5
H
Formerly, 7.30 g of TiISP and 10.4 g of PbAC were added to the above
mixture with enthusiastic rousing for 60 min. Then, the ensuing sol was
relocated to a Petri dish. The dish was put into a heater for a 12 h at 40
where C
i
is the initial ThP concentration and C
t
represents the concen-
tration of ThP after visible light illumination time (t). The photo-
produced gases evolved from the reactor outlet were passed to liberated
◦
◦
C and another 12 h 65 C to vaporize the C
2
H
5
OH marginally. After
solutions of NaOH and HNO
(supplementary materials).
3
to confirm the degradation pathway of ThP
that, to crystallize the PTO and remove F-127, the hard gel furtherly
◦
ꢀ 1
◦
heated with a rate of 1.0 C min for 4 h to 450 C in air and slowly
cooled for another 4 h by the same rate [21,41].
3. Results and discussion
2
.3. Preparation of PTO@rGO photocatalysts
3.1. Structural description and optical depiction of produced substances
Graphite was oxidized to produce GO nanosheets by oxidizing agents
Fig. 1 illustrates the XRD patterns of the as-synthesized samples. The
pattern demarcated with a is typically identified as perovskite PbTiO3
crystalline phase (PTO, PDF no. 74-2495) as all diffraction planes are
characteristically agreed with the (hkl) indices provided in Fig. 1 [31].
The patterns b, c, d, and e represent the PTO@x%rGO at x = 3, 6, 9, and
12 wt.% of rGO, separately are showing an additional peak around 2θ =
similarly as our previous publications (see supplementary materials)
19,20]. The pre-calculated amount of GO was firstly adjourned in 50
mL of C OH by sonicator. In a separate glass flask, 200 mg of PTO was
also spread in 100 mL of C OH. Afterwards, the PTO suspension was
[
2 5
H
2 5
H
ꢀ 1
slowly released on the GO dispersion at 120 mL h by the burette under
energetic rousing till the solution was poured within 50 min. The
○
23.2 specifying the (002) index of the rGO support [32,38]. The result
◦
mixture was formerly heated to 65 C for 4 h to yield the rGO-supported
also advocates the successful reduction of GO to rGO while adding PTO
as depicted by XRD and Raman spectra in Fig. S1 (supplementary ma-
terials). As for XRD, no observable peaks were showing any impurities.
The diffraction peak intensities of the PTO diminished by increasing the
amount of rGO, leaving exposed (111) facet for PTO [37].
PTO (eminent as PTO@x%rGO) by self-reduction [42], where x% is the
amount of the rGO to the PTO at 0, 3, 6, 9, and 12 wt.%.
The high-resolution XPS expressing Pb4f, Ti2p and O1s, and C1S core
2

M. Alhaddad et al.
Molecular Catalysis xxx (xxxx) xxx
eV revealing the existence of C
respectively. This result indicates the formation of defected rGO [19,20,
4]. This observation suggests the rGO is chronologically formed
–
C, C
–
O, and C
–
O core levels,
4
through the addition of PTO to GO [36]. Therefore, the chemical state of
the PTO@9%rGO sample is unveiled.
As for the nanomorphological study, Fig. 3a‒c compares the TEM
images of the synthesized PTO, rGO, and PTO@9%rGO samples, indi-
vidually. The PTO sample (Fig. 3a) exhibited aggregated nanospherical
particles having diameters ranged 25–42 nm as described by histogram
appeared in Fig. S3 (supplementary materials). The exfoliated rGO
appeared in Fig. 2b indicated the 2-dimensional sheets with a nearly flat
surface with few wrinkles. However, the PTO@9% rGO sample disclosed
detached nanospheres (7~15 nanoparticles) consistently appeared on
the rGO sheets having an average diameter of 50 nm (Fig. 3c). The
HRTEM image of one selected aggregate approves the comparable
interplanar distance of 0.284 nm for the (101) plane of the PTO crystal,
while the rGO was also confirmed with the (002) plane with interplanar
spacing of 0.34 nm as seen in Fig. 3d [38].
Fig. 1. XRD patterns of produced samples of different PTO@x%rGO samples at
x = 0, 3, 6, 9, and 12 wt.% as represented by a, b, c, d, and e, correspondingly.
The conforming (hkl) planes of perovskite PTO interpretation to the defined
PDF card as provided.
2
The N adsorption/desorption isotherms of the pure PTO, PTO@3%
rGO, and PTO@9%rGO are presented in Fig. 4 to study the effect of rGO
on the surface texture of PTO nanospheres. The isotherms of the samples
featured an IV type with H2 hysteresis indicating the mesoporous
structured surfaces. The variation in sharpness is ensuring at a
level spectra of selected PTO@9%rGO sample are displayed in Fig. 2a, b,
0
comparative pressure (P/P ) of 0.65~0.9, forming a tube-like abridge-
c, and d, correspondingly. The findings proved the existence of Pb2 of
PTO lattice [32], due to the appearance of two peaks at 138.7 and 142.8
eV for Pb4f7/2 and Pb4f5/2, respectively, as displayed in Fig. 2a. The
+
ment of three-dimensional interconnecting pores [45]. The
BET-calculated surface areas (SBET) of all samples are listed in Table 1.
The original SBET of pure PTO recorded at 190 m2
–1
g
. Though the
PTO@x%rGO exhibited a slight increase in SBET values to 194, 198, 205,
3
+
outcomes also proved the existence of Ti in perovskite crystals [21,
2], due to the presence of two mountains at 458.8 and 464.4 eV for
2
and 207 m2
–1
g
by mounting the rGO content at 3, 6, 9 and 12 wt.%,
Ti2p3/2 and Ti2p1/2, singly (Fig. 2b) [32,37,38]. The existence of the O1s
peak at 532.4 eV confirms the O ion in the PTO lattice as publicized in
Fig. 2c. The C1s expanse upon the reduction of rGO with the suspension
of the PTO exists in Fig. 2d. The detailed XPS is also appeared in Fig. S2
likewise. Thus, the exhibition of rGO boosts the pore solidity of the
aggregated PTO particles and, accordingly, the photocatalytic perfor-
mance [46,47].
Regarding the light-harvesting of the gained photocatalysts, the
(
supplementary materials). The fitted peaks indicate the observation of
UV–vis-NIR absorption spectra appeared in Fig. 5 with predictable E
values in the inset (Table 1). The absorption spectra of different rGO
g
three mountains. The graphitized peaks located at 284.6, 286 and 287.8
Fig. 2. HRXPS of selected PTO@9%rGO sample showing Pb4f (a), Ti2p (b), O1s in (c), and C1s in (D).
3

M. Alhaddad et al.
Molecular Catalysis xxx (xxxx) xxx
Fig. 3. TEM images of PTO (a), rGO (b), and selected PTO@9%rGO nanocomposite in (c). The HRTEM image presenting lattice bounds for both PTO and rGO is
embodied in (d) as indicated.
g
nm and lessens the E to 1.90 eV for the PTO@9%rGO sample, as pre-
sented in Fig. 5. The influence of the rGO contacted PTO evolves the
harvesting of light and thus enhances the photoactivity [32,36,39]. The
slight increase of the E
g
for the PTO@12 %rGO may refer to either ag-
gregation of PTO particles or incomplete reduction of rGO content [19,
2
0,32].
3
3
.2. Photocatalytic performance of PTO@rGO for the oxidation of ThP
.2.1. Influence of rGO content
Fig. 6 explains the photooxidation of ThP beneath 150 min of visible
–
1
light radiation utilizing 1.25 g L of PTO@x%rGO. Fig. 6a shows an
increase of POD of ThP as time goes and also with the rising of rGO
content (Table 1). The bare PTO appeared an average POD of 45 % of
ThP. Though, the PTO@3wt.% rGO photocatalyst indicated an
improved POD to 55 %. By cumulating the rGO expanse to the PTO
nanospheres to 6 and 9 wt.%, the POD of ThP raised dramatically to 85
and 99 %, consistently. Regarding the oxidative desulfurization rate of
ThP, The first-order reaction kinetic model is applied to calculate the
photooxidation rate constant (KOD) of ThP by [18];
(
)
Fig. 4. Nitrogen adsorption/desorption isotherms of PTO, PTO@6%rGO, and
C
C
t
ln
= ꢀ KOD
t
(2)
PTO@9%rGO nanocomposites as signposted.
i
The fitted lines displayed in Fig. 6b indicated the KOD values
amounts supported PTO nanospheres showed a broadening of the ab-
sorption edge and intensity (Table 1). The bare PTO shows an absorption
ꢀ 1
enhanced to 0.023 min , for the use of PTO@9%rGO photocatalyst,
from 0.004 for the PTO only as tabulated in Table 1 with considerable R-
squared values as well. These results signify the role rGO occurrence for
the enhancement of photooxidation competence of ThP. The more
edge lies in the visible region at 465 nm, and gives an E
g
of 2.45 eV.
However, the introduction of rGO enhances the light captivation to 613
4

M. Alhaddad et al.
Molecular Catalysis xxx (xxxx) xxx
Table 1
Influence of rGO adding to the pure PTO on their different physicochemical properties (specific surface area (SBET), absorption edge (Abs. edge), appraised bandgap
energies (E
Sample
PTO
g
), PL emission peak positions, and photocurrent (PC) within 30 s at ON state), and their corresponding photooxidation efficiency of ThP within 150 min.
2
–1
–1
2
ꢀ 1
PC (mAcm )
S
BET (m
g
)
Abs. edge (nm)
E
g
(eV)
P
OD*(%)
KOD (min
)
R
PL peaks (nm)
190
194
198
205
207
465
608
611
613
612
2.45
1.95
1.92
1.90
1.91
45
0.004
0.005
0.012
0.023
0.021
0.96
0.95
0.98
0.97
0.98
493
611
644
693
692
0.31
0.38
0.74
1.43
1.41
PTO@3 %rGO
PTO@6 %rGO
PTO@9 %rGO
PTO@12 %rGO
55
85
100
99
g
to the lessening of E by the conductive rGO addition. Also, the PL in-
tensities are reduced by increasing the rGO content at 9 wt.% (Fig. 7a).
This quenching of the PL signifies the lower recombination of the pho-
togenerated charges at the PTO/rGO interface [19,36]. Hence, the su-
perior photocatalytic performance of the produced PTO@9%rGO among
other counterparts. Transient photocurrent extents additionally evi-
dence this confirmation as in Fig. 7b. The PTO@9%rGO photocatalyst
exhibits a 4.5-time photocurrent value compared to the PTO (Table 1),
occasioning an easier photocharge transference at the PTO-PTO and
PTO/rGO interfaces [20,38,39,50]. Thus, the adjusted rGO addition
improves the photocatalytic enactment of the produced PTO
nanospheres.
3
.2.2. Influence of the dose and reusing ability of the PTO@rGO
Fig. 8 establishes the enhanced PTO@9%rGO photocatalyst dosage
–
1
on the POD of ThP. The PTO@rGO dosage altered from 0.5 to 2.5 g L
.
The POD was enlarged by raising the amount of PTO@9%rGO from 0.5 to
–
1
.5 g L 1 as 45–99% within 120 min light irradiation (Fig. 8a). While
–
1
increasing dosage to 2.0 gL achieves the complete photooxidation of
ThP after just 60 min of lighting compared to lower POD to the lower
doses (Fig. 8b, Table 2). In opposition, the additional amount of
Fig. 5. UV–vis-NIR DRS and predictable bandgap energies using Kubelka-Munk
formulation (inset) of the formed photocatalysts a designated.
–
1
PTO@rGO to 2.5 g L showed a poorer POD of 54 and 85 % after shining
the light for 60 and 150 min, individually (Fig. 8a). The fitted curves
obtained by the natural logarithm of the relative concentration change
magnificent POD is assigned to the upgrading of the surface properties
and light fascination by the incidence of rGO. The additional did not
increase the POD as it may thwart the light from getting the dynamic
photoactive spots of PTO nanospheres and subsequently reduces the
performance as a result [19,20].
ꢀ
1
of ThP (Fig. 8c) indicated the KOD values also boosted to 0.066 min , a
– –1
.33-time greater for the use of 2.0 gL 1 compared to 0.5 gL of
7
PTO@9%rGO photocatalyst with acceptable R-squared value (Fig. 8d,
Table 2). The further dose may mount up the PTO@9%rGO accumula-
tion that impedes the incident photons to get the photoactive locations
on the photocatalyst surface. As a consequence, the bare portions to the
ThP molecules could be sunk, instigating a minimization of the POD [22,
Concerning the charge separation and mobility induced by the
introduction of rGO, the PL spectra and photocurrent intensity mea-
surements of the produced PTO@x%rGO are displayed in Fig. 7a, and
Fig. 7b, respectively. The PL is meaningful evidence to judge the pho-
tocharge recombination of the given photocatalyst [48,49]. The bare
PTO nanospheres express a green PL positioned at 493 nm by excitation
of 465 nm laser. The PL behavior of PTO@rGO photocatalysts features
redshifts of 118, 151, 200, and 199 nm by 3, 6, 9, and 12 % of rGO
content, correspondingly as recorded in Table 1. These outcomes are due
5
1]. Table 3 listed the current research results on the oxidative desul-
furization of ThP using various photocatalysts compared to this work
[
19,20,52–57]. The data demonstrated that our optimized PTO@rGO
photocatalyst is the most magnificent. The optimized dose of PTO@9%
rGO demonstrated insignificant adsorption of ThP when compared to
Fig. 6. Photooxidative desulfurization efficiency of ThP by the fashioned photocatalysts as the irradiation time goes in (a). The first-order kinetic model of ThP
ꢀ 1
removal using PTO@x%rGO at 1.25 g L is visible in (b).
5

M. Alhaddad et al.
Molecular Catalysis xxx (xxxx) xxx
Fig. 7. PL spectra (a) and transient photocurrent (b) investigations of PTO@x%rGO photocatalysts as specified.
Fig. 8. Influence of the PTO@9%rGO photocatalyst dosage on the photooxidative desulfurization (POD) of ThP in (a). The bar-graph signified POD after passing 60
min in (b). The first-order reaction model using different doses of PTO@9%rGO illustrated in (c), and desulfurization rate constant (KOD) done by the line fitting
in (d).
◦
photocatalyst was restored by drying at 150 C next to each photo-
Table 2
catalytic test. The augmented PTO@9%rGO photocatalyst sustains 93 %
Influence of PTO@9%rGO photocatalyst dose on the photooxidation efficiency
of its first POD within five different cycles without a significant change in
of ThP after 60 min of light irradiation.
its structure or PL behavior (Fig. S5, supplementary materials). There
ꢀ
1
–1
2
PTO@9% rGO Dose (gL
)
P
OD*(±SD%)
K
OD (min
)
R
was no observation of Pb or Ti impurities in solution by inductive
coupling plasma after regeneration. So, the produced PTO@9%rGO
photocatalyst discloses significant application for industrialized
resolves.
0
1
1
2
2
.5
.0
.5
.0
.5
35 ± 3.3
48 ± 4.5
73 ± 5.7
100 ± 0.5
54 ± 4.5
0.009
0.012
0.023
0.066
0.014
0.94
0.91
0.93
0.94
0.91
3
.2.3. Anticipated photocatalytic process
The visible-light-oxidation of ThP by the adjusted PTO@rGO nano-
the photolysis experiment (Fig. S4, supplementary materials). Moreover,
the robustness of the PTO@rGO photocatalyst was comprehended by the
regeneration-reusing testing, as presented in Fig. 9. The consumed
composite is suggested in Fig. 10. The incidence of the light photons
+
induce excitons and separated into electrons (e–s) and holes (h s) at the
conduction (CB) and valence (VB) edges, consistently as in (3) [58,59].
6

M. Alhaddad et al.
Molecular Catalysis xxx (xxxx) xxx
ꢀ
+
Table 3
PTO + h
ν
→e + h
(3)
CB
VB
Comparative activity of different materials towards the photooxidation of ThP
under visible-light radiance to this work.
The e–s situated at the CB can credibly transport to the attached rGO,
+
while the h remains at the VB. Accordingly, the consequential sepa-
Photocatalyst
PO
%)
Time
Dose
Light source
power/type
Ref.
–
1
ration of the photocharges arises. Formerly, the oxidation sorts are
created in (4) and (5) as [60,61];
(
(min.)
(gL
)
Na-doped g-C
3
N
4
100
88
360
180
180
270
120
90
5.0
300 W/Xe
lamp
[52]
[53]
[54]
[55]
[56]
[57]
[19]
[20]
ꢀ
→ ∙Oꢀ
e
(rGO) + O
2
(4)
(5)
CB
2
2
ꢀ
-TiO
RuO
2
/SO
4
2
1.0
1.0
1.5
0.8
2.0
1.6
1.2
2.0
300 W/Hg
lamp
+
h
2
(PTO) + H Oads.→ ∙OH
VB
Ni,CuO-doped
BiVO
Ag/ -MoO
94.5
98.3
100
100
100
100
100
300 W/Xe
lamp
4
The generated superoxide and hydroxyl radicals were identified by
α
3
500W/Xe
lamp
ESR investigation through light illumination as seen in Fig. 10a. These
radicals can perceptibly react with the ThP molecules on the photo-
Fe
Bi
ZrO
3
O
4
@SiO
WO /Bi
-SiO
2
/
500W/Xe
lamp
2
6
2
S
3
catalyst surface, ensuing the oxidation yields of SO
3
, CO
2
, as perceived
O.
2
2
125W/Hg
lamp
in Fig. 10b and proved in Fig. S6 (supplementary materials), and H
2
These mineralized substances were proved by XRD examination of the
precipitates formed after passing the gases from the outlet of the reactor
CdSe/15 %rGO
MoS @15 %rGO
PbTiO @9 %rGO
90
300 W/Hg
lamp
2
75
125W/Xe
lamp
on solutions of NaOH, Ba(NO
3 2 3
) , and HNO (supplementary materials).
As a result, the ThP is entirely photooxidized under visible light expo-
3
60
300 W/Xe
lamp
This
sure by PTO@rGO photocatalyst into CO
2
and SO
3
corresponding to (6);
(6)
work
/
ꢀ
O
(and or ∙OH) + ThPads→ CO
2
+SO
3
+ H O
2
2
4
. Conclusions
A simple step prepared for the rGO-attached sol-gel synthesized
PbTiO
PbTiO
3
nanospheres is presented. The appropriate rGO expanse to the
has positively advanced the superficial, optical, and photoelec-
3
tronic possessions of the fashioned PbTiO
3
@rGO. The consistent
dispersion of PbTiO that leads to an increase in surface area. Further-
3
more, the bandgap energy abridged to 1.90 eV with an expansion of light
fascination and surpassing the photocharge separation. The photooxi-
3
dation of ThP substantiated the photoactivity of PbTiO @rGO as a stable
industrialized sulfur-containing model. The total removal of 600 ppm
sulfur-contained ThP was attained by 60 min of light acquaintance using
ꢀ 1
a 2.0 gL
3
of the PbTiO @rGO in solution. This innovative nano-
composite demonstrated a robust ability to reutilize for five times as
well. The anticipated photoactivity specifies the incidence of the rGO
develops the photooxidation capability. This work ropes the commen-
dation of perovskite-based photocatalysts in the next environmental
remediation technology.
CRediT authorship contribution statement
Fig. 9. Impression of the PTO@9%rGO photocatalyst on the (POD) of ThP
viewing the constancy for five successive runs.
Maha Alhaddad: Conceptualization, Methodology, Investigation,
Resources, Project administration. Ahmed Shawky: Validation, Formal
analysis, Writing - original draft, Writing - review & editing, Visualiza-
tion, Supervision. Z.I. Zaki: Formal analysis, Writing - review & editing.
Fig. 10. ESR spectra investigation of the produced super oxide and hydroxyl radicals in dark and after light radiation for 10 min in (a). The proposed photocatalytic
scheme of PTO@9%rGO for oxidative desulfurization of ThP is illustrated in (b).
7

M. Alhaddad et al.
Molecular Catalysis xxx (xxxx) xxx
Declaration of Competing Interest
visible light irradiation, Appl. Nanosci. 10 (2020) 1545–1554, https://doi.org/
1
0.1007/s13204-019-01212-0.
[
[
19] I.A. Mkhalid, A. Shawky, Visible light-active CdSe/rGO heterojunction
photocatalyst for improved oxidative desulfurization of thiophene, Ceram. Int. 47
(2020) 20769–20776, https://doi.org/10.1016/j.ceramint.2020.05.033.
20] M. Alhaddad, A. Shawky, Superior photooxidative desulfurization of thiophene by
reduced graphene oxide-supported MoS2 nanoflakes under visible light, Fuel
Process. Technol. 205 (2020) 106453, https://doi.org/10.1016/j.
fuproc.2020.106453.
The authors declare that they have no known competing for financial
interests or personal relationships that could have appeared to influence
the work reported in this paper.
Acknowledgements
[
[
21] A. Shawky, M. Alhaddad, K.S. Al-Namshah, R.M. Mohamed, N.S. Awwad, Synthesis
of Pt-decorated CaTiO3 nanocrystals for efficient photoconversion of nitrobenzene
to aniline under visible light, J. Mol. Liq. 304 (2020) 112704, https://doi.org/
10.1016/j.molliq.2020.112704.
22] A. Shawky, R.M. Mohamed, I.A. Mkhalid, M.A. Youssef, N.S. Awwad, Visible light-
responsive Ag/LaTiO3 nanowire photocatalysts for efficient elimination of atrazine
herbicide in water, J. Mol. Liq. 299 (2020) 112163, https://doi.org/10.1016/j.
molliq.2019.112163.
Authors thank the Taif University Researchers Supporting Project
(
TURSP-2020/42), Taif University, Taif Saudi Arabia.
Appendix A. Supplementary data
[
[
23] A. Kumar, S. Kumar, V. Krishnan, Perovskite-Based Materials for Photocatalytic
Environmental Remediation, 2019, pp. 139–165, https://doi.org/10.1007/978-3-
Supplementary material related to this article can be found, in the
online version, at doi:https://doi.org/10.1016/j.mcat.2020.111301.
0
30-10609-6_5.
24] L. Paramanik, K.H. Reddy, S. Sultana, K. Parida, Architecture of biperovskite-based
LaCrO 3 /PbTiO 3 p-n heterojunction with a strong interface for enhanced charge
anti-recombination process and visible light-induced photocatalytic reactions,
Inorg. Chem. 57 (2018) 15133–15148, https://doi.org/10.1021/acs.
inorgchem.8b02364.
25] L. Paramanik, K. Parida, Efficient perovskite titanate photocatalysts for oxygen
evolution reactions, Mater. Today Proc. (2020) 10–13, https://doi.org/10.1016/j.
matpr.2020.03.523.
26] J. Han, Y. Liu, F. Dai, R. Zhao, L. Wang, Fabrication of CdSe/CaTiO 3
nanocomposties in aqueous solution for improved photocatalytic hydrogen
production, Appl. Surf. Sci. 459 (2018) 520–526, https://doi.org/10.1016/j.
apsusc.2018.08.026.
27] S. Su a´ rez-V a´ zquez, A. Cruz-L o´ pez, C. Molina-Guerrero, A. S ´a nchez-V ´a zquez,
C. Macías-Sotelo, Effect of dopant loading on the structural and catalytic properties
of Mn-doped SrTiO3 catalysts for catalytic soot combustion, Catalysts 8 (2018) 71,
https://doi.org/10.3390/catal8020071.
References
[
1] M. Xiu, S. Stevanovic, M.M. Rahman, A.M. Pourkhesalian, L. Morawska, P.K. Thai,
Emissions of particulate matter, carbon monoxide and nitrogen oxides from the
residential burning of waste paper briquettes and other fuels, Environ. Res. 167
[
[
(
2018) 536–543, https://doi.org/10.1016/j.envres.2018.08.008.
[
[
2] R.M. Mohamed, A. Shawky, I.A. Mkhalid, Facile synthesis of MgO and Ni-MgO
nanostructures with enhanced adsorption of methyl blue dye, J. Phys. Chem. Solids
1
01 (2017) 50–57, https://doi.org/10.1016/j.jpcs.2016.10.009.
3] M.A. Rezvani, M. Shaterian, F. Akbarzadeh, S. Khandan, Deep oxidative
desulfurization of gasoline induced by PMoCu@MgCu2O4-PVA composite as a
high-performance heterogeneous nanocatalyst, Chem. Eng. J. 333 (2018) 537–544,
https://doi.org/10.1016/j.cej.2017.09.184.
[
[
[
4] N.B. Suryawanshi, V.M. Bhandari, L.G. Sorokhaibam, V.V. Ranade, Developing
techno-economically sustainable methodologies for deep desulfurization using
hydrodynamic cavitation, Fuel 210 (2017) 482–490, https://doi.org/10.1016/j.
fuel.2017.08.106.
28] M. Bradha, T. Vijayaraghavan, S.P. Suriyaraj, R. Selvakumar, A.M. Ashok,
Synthesis of photocatalytic La(1-x)AxTiO3.5-δ (A=Ba, Sr, Ca) nano perovskites and
their application for photocatalytic oxidation of congo red dye in aqueous solution,
J. Rare Earths 33 (2015) 160–167, https://doi.org/10.1016/S1002-0721(14)
[
[
[
5] K. Kawashima, Y. Tamai, H. Ohkita, I. Osaka, K. Takimiya, High-efficiency polymer
solar cells with small photon energy loss, Nat. Commun. 6 (2015) 1–9, https://doi.
org/10.1038/ncomms10085.
6] G. Barbarella, M. Zangoli, F. Di Maria, Synthesis and applications of thiophene
derivatives as organic materials, Adv. Heterocycl. Chem. 123 (2017) 105–167,
https://doi.org/10.1016/bs.aihch.2017.01.001.
7] P. Hammarstr o¨ m, R. Simon, S. Nystr o¨ m, P. Konradsson, A. Åslund, K.P.R. Nilsson,
A fluorescent pentameric thiophene derivative detects in vitro-formed prefibrillar
protein aggregates, Biochemistry 49 (2010) 6838–6845, https://doi.org/10.1021/
bi100922r.
6
0397-5.
[
[
29] G. Liu, L. Ma, L.C. Yin, G. Wan, H. Zhu, C. Zhen, Y. Yang, Y. Liang, J. Tan, H.
M. Cheng, Selective chemical epitaxial growth of TiO2 islands on ferroelectric
PbTiO3 crystals to boost photocatalytic activity, Joule 2 (2018) 1095–1107,
https://doi.org/10.1016/j.joule.2018.03.006.
30] H. Kooshki, A. Sobhani-Nasab, M. Eghbali-Arani, F. Ahmadi, V. Ameri, M. Rahimi-
Nasrabadi, Eco-friendly synthesis of PbTiO3 nanoparticles and PbTiO3/carbon
quantum dots binary nano-hybrids for enhanced photocatalytic performance under
visible light, Sep. Purif. Technol. 211 (2019) 873–881, https://doi.org/10.1016/j.
seppur.2018.10.057.
[
[
8] D. Gramec, L. Peterlin Ma ˇs i ˇc , M. Sollner Dolenc, Bioactivation potential of
thiophene-containing drugs, Chem. Res. Toxicol. 27 (2014) 1344–1358, https://
doi.org/10.1021/tx500134g.
9] M. Doble, A. Kumar, in: M. Doble, A.B.T.-B. of I.E. Kumar (Eds.), CHAPTER 30 -
Gaseous Pollutants and Volatile Organics, Butterworth-Heinemann, Burlington,
[
[
31] J.S. Jang, C.W. Ahn, S.S. Won, J.H. Kim, W. Choi, B.S. Lee, J.H. Yoon, H.G. Kim, J.
S. Lee, Vertically aligned core-shell PbTiO3@TiO2 heterojunction nanotube array
for photoelectrochemical and photocatalytic applications, J. Phys. Chem. C 121
(
2017) 15063–15070, https://doi.org/10.1021/acs.jpcc.7b03081.
2
005, pp. 301–312, https://doi.org/10.1016/B978-075067838-4/50031-2.
32] Q. Peng, X. Weng, W. Xie, M. Ying, X. Lin, Y. Dai, Q. Yu, H. Pan, J. Liu, M. Du,
Photocatalytic reduction for graphene oxide by PbTiO3 with high polarizability
and its electrocatalytic application in pyrrole detection, J. Colloid Interface Sci.
[
[
10] G.S. Nyashina, K.Y. Vershinina, N.E. Shlegel, P.A. Strizhak, Effective incineration
of fuel-waste slurries from several related industries, Environ. Res. 176 (2019)
1
08559, https://doi.org/10.1016/j.envres.2019.108559.
5
60 (2020) 502–509, https://doi.org/10.1016/j.jcis.2019.10.022.
11] A.A. Zardini, R. Suarez-Bertoa, F. Forni, F. Montigny, M. Otura-Garcia, M. Carriero,
C. Astorga, Reducing the exhaust emissions of unregulated pollutants from small
gasoline engines with alkylate fuel and low-ash lube oil, Environ. Res. 170 (2019)
[
[
33] X. Zeng, Y. Liu, X. Wang, W. Yin, L. Wang, H. Guo, Preparation of nanocrystalline
PbTiO3 by accelerated sol-gel process, Mater. Chem. Phys. 77 (2003) 209–214,
https://doi.org/10.1016/S0254-0584(01)00558-2.
2
03–214, https://doi.org/10.1016/j.envres.2018.12.021.
34] X. Sun, S. Deng, Y. Yang, G. Xu, R. Zhao, G. Shen, G. Han, Hydrothermal synthesis
and photocatalytic activity of Li-doped PbTiO3 perovskite cubic particles, Surf.
Coat. Technol. 320 (2017) 527–530, https://doi.org/10.1016/j.
[
[
12] L. Tang, S. Wang, X. Zhu, Y. Guan, S. Chen, X. Tao, H. He, Feasibility study of
reduction removal of thiophene sulfur in coal, Fuel 234 (2018) 1367–1372,
https://doi.org/10.1016/j.fuel.2018.08.016.
surfcoat.2016.11.027.
13] G. Wang, G. Chen, W. Xie, W. Wang, L. Bing, Q. Zhang, H. Fu, F. Wang, D. Han,
Three-dimensionally ordered macroporous bulk catalysts with enhanced catalytic
performance for thiophene hydrodesulfurization, Fuel Process. Technol. 199
[
[
35] C.W. Ahn, P.H. Borse, J.H. Kim, J.Y. Kim, J.S. Jang, C.R. Cho, J.H. Yoon, Bseob Lee,
J.S. Bae, H.G. Kim, J.S. Lee, Effective charge separation in site-isolated Pt-nanodot
deposited PbTiO3 nanotube arrays for enhanced photoelectrochemical water
splitting, Appl. Catal. B Environ. 224 (2018) 804–809, https://doi.org/10.1016/j.
apcatb.2017.11.002.
(
2020) 106268, https://doi.org/10.1016/j.fuproc.2019.106268.
[
[
14] X.L. Sun, Z. Liu, Z.L. Cheng, Design and fabrication of in-situ N-doped paper-like
carbon nanofiber film for thiophene removal from a liquid model fuel, J. Hazard.
Mater. (2019) 121879, https://doi.org/10.1016/j.jhazmat.2019.121879.
15] X. Zeng, X. Xiao, J. Chen, H. Wang, Electron-hole interactions in choline-
phosphotungstic acid boosting molecular oxygen activation for fuel
36] A. Kumar, S. Kumar, A. Bahuguna, A. Kumar, V. Sharma, V. Krishnan, Recyclable,
bifunctional composites of perovskite type N-CaTiO3 and reduced graphene oxide
as an efficient adsorptive photocatalyst for environmental remediation, Mater.
Chem. Front. 1 (2017) 2391–2404, https://doi.org/10.1039/c7qm00362e.
37] C. Wang, L. Shan, D. Song, Y. Xiao, J. Suriyaprakash, Hydrothermal synthesis of
rGO/PbTiO3 photocatalyst and its photocatalytic H2 evolution activity,
J. Nanomater. 2019 (2019), https://doi.org/10.1155/2019/4869728.
38] L. Paramanik, K.H. Reddy, K.M. Parida, An energy band compactable B-rGO/
PbTiO3 p-n junction: a highly dynamic and durable photocatalyst for enhanced
photocatalytic H2 evolution, Nanoscale 11 (2019) 22328–22342, https://doi.org/
desulfurization, Appl. Catal. B Environ. 248 (2019) 573–586, https://doi.org/
[
[
1
0.1016/j.apcatb.2018.09.038.
[
16] S. yong Dou, R. Wang, Study on the performance and mechanism of aerobic
oxidative desulfurization based on a dual-functional material possessing catalytic
and adsorptive properties, New J. Chem. 43 (2019) 3226–3235, https://doi.org/
1
0.1039/c8nj05896b.
[
[
17] K. K ˆe dra-Kr o´ lik, M. Fabrice, J.N. Jaubert, Extraction of thiophene or pyridine from
n-heptane using ionic liquids. Gasoline and diesel desulfurization, Ind. Eng. Chem.
Res. 50 (2011) 2296–2306, https://doi.org/10.1021/ie101834m.
1
0.1039/c9nr06378a.
[
39] J. Yun, H. Fan, Y. Zhang, R. Huang, Y. Ren, M. Guo, H. An, P. Kang, H. Guo,
Enhanced optical absorption and interfacial carrier separation of CsPbBr3/
Graphene heterostructure: experimental and theoretical insights, ACS Appl. Mater.
Interfaces 12 (2020) 3086–3095, https://doi.org/10.1021/acsami.9b13179.
18] A. Shawky, R.M. Mohamed, I.A. Mkhalid, N.S. Awwad, A. Ibrahium, H.
A. Ibrahium, One-pot synthesis of Mn3O4-coupled Ag2WO4 nanocomposite
photocatalyst for enhanced photooxidative desulfurization of thiophene under
8

M. Alhaddad et al.
Molecular Catalysis xxx (xxxx) xxx
[
[
40] X. Zeng, X. Xiao, Y. Li, J. Chen, H. Wang, Deep desulfurization of liquid fuels with
molecular oxygen through graphene photocatalytic oxidation, Appl. Catal. B
Environ. 209 (2017) 98–109, https://doi.org/10.1016/j.apcatb.2017.02.077.
41] T.Z. Fermino, C.M. Awano, L.X. Moreno, D.R. Vollet, F.S. de Vicente, Structure and
thermal stability in hydrophobic Pluronic F127-modified silica aerogels,
Microporous Mesoporous Mater. 267 (2018) 242–248, https://doi.org/10.1016/j.
micromeso.2018.03.039.
photocatalyst with superb activity, J. Environ. Chem. Eng. 7 (2019) 103174,
https://doi.org/10.1016/j.jece.2019.103174.
[52] X. Zhang, H. Song, C. Sun, C. Chen, F. Han, X. Li, Photocatalytic oxidative
desulfurization and denitrogenation of fuels over sodium doped graphitic carbon
nitride nanosheets under visible light irradiation, Mater. Chem. Phys. 226 (2019)
34–43, https://doi.org/10.1016/j.matchemphys.2019.01.011.
[53] F. Lin, Z. Jiang, N. Tang, C. Zhang, Z. chen, T. Liu, B. Dong, Photocatalytic
oxidation of thiophene on RuO2/SO42–TiO2: insights for cocatalyst and solid-acid,
Appl. Catal. B Environ. 188 (2016) 253–258, https://doi.org/10.1016/j.
apcatb.2016.02.016.
[54] F. Lin, Z. Shao, P. Li, Z. Chen, X. Liu, M. Li, B. Zhang, J. Huang, G. Zhu, B. Dong,
Low-cost dual cocatalysts BiVO4 for highly efficient visible photocatalytic
oxidation, RSC Adv. 7 (2017) 15053–15059, https://doi.org/10.1039/
c6ra27559a.
[
[
[
42] D. Hou, Q. Liu, X. Wang, Y. Quan, Z. Qiao, L. Yu, S. Ding, Facile synthesis of
graphene via reduction of graphene oxide by artemisinin in ethanol, J. Mater. 4
(
2018) 256–265, https://doi.org/10.1016/j.jmat.2018.01.002.
43] A.A. Ismail, R.M. Mohamed, O.A. Fouad, I.A. Ibrahim, Synthesis of nanosized ZSM-
5
using different alumina sources, Cryst. Res. Technol. 41 (2006) 145–149, https://
doi.org/10.1002/crat.200510546.
44] S. Stankovich, D.A. Dikin, R.D. Piner, K.A. Kohlhaas, A. Kleinhammes, Y. Jia,
Y. Wu, S.B.T. Nguyen, R.S. Ruoff, Synthesis of graphene-based nanosheets via
chemical reduction of exfoliated graphite oxide, Carbon 45 (2007) 1558–1565,
https://doi.org/10.1016/j.carbon.2007.02.034.
45] J.Y. Do, Y. Im, B.S. Kwak, S.M. Park, M. Kang, Preparation of basalt fiber@
perovskite PbTiO3 core-shell composites and their effects on CH4 production from
CO2 photoreduction, Ceram. Int. 42 (2016) 5942–5951, https://doi.org/10.1016/
j.ceramint.2015.12.142.
[55] Y. Zhen, J. Wang, F. Fu, W. Fu, Y. Liang, The novel z-scheme ternary-component
ag/agi/ -moo3 catalyst with excellent visible-light photocatalytic oxidative
α
desulfurization performance for model fuel, Nanomaterials 9 (2019), https://doi.
org/10.3390/nano9071054.
[
[
[56] L. Guo, Q. Zhao, C. Wang, H. Shen, X. an Han, K. Zhang, D. Wang, F. Fu,
Magnetically recyclable Fe3O4@SiO2/Bi2WO6/Bi2S3 with visible-light-driven
photocatalytic oxidative desulfurization, Mater. Res. Bull. 118 (2019) 110520,
https://doi.org/10.1016/j.materresbull.2019.110520.
[57] A.S. Basaleh, R.M. Mohamed, Photodegradation of thiophene over ZrO2–SiO2
nanoparticles: impact of copper decoration on their photocatalytic activity, Appl.
Nanosci. 9 (2019) 2051–2058, https://doi.org/10.1007/s13204-019-00992-9.
[58] R.M. Mohamed, Characterization and catalytic properties of nano-sized Pt metal
catalyst on TiO2-SiO2 synthesized by photo-assisted deposition and impregnation
methods, J. Mater. Process. Technol. 209 (2009) 577–583, https://doi.org/
10.1016/j.jmatprotec.2008.02.027.
[59] R.M. Mohamed, E. Aazam, Synthesis and characterization of P-doped TiO2 thin-
films for photocatalytic degradation of butyl benzyl phthalate under visible-light
irradiation, Cuihua Xuebao/Chin. J. Catal. 34 (2013) 1267–1273, https://doi.org/
10.1016/S1872-2067(12)60572-5.
[60] R.M. Mohamed, I.A. Mkhalid, E.S. Baeissa, M.A. Al-Rayyani, Photocatalytic
degradation of methylene blue by Fe/ZnO/SiO 2 nanoparticles under visiblelight,
J. Nanotechnol. 2012 (2012), https://doi.org/10.1155/2012/329082.
[61] R.M. Mohamed, M. Abdel Salam, Photocatalytic reduction of aqueous mercury(II)
using multi-walled carbon nanotubes/Pd-ZnO nanocomposite, Mater. Res. Bull. 50
(2014) 85–90, https://doi.org/10.1016/j.materresbull.2013.10.031.
46] I.A. Abdel-Latif, L.A. Al-Hajji, M. Faisal, A.A. Ismail, Doping strontium into
neodymium manganites nanocomposites for enhanced visible light driven
photocatalysis, Sci. Rep. 9 (2019) 13932, https://doi.org/10.1038/s41598-019-
5
0393-9.
[
[
47] C. Xue, H. An, G. Yang, Facile construction of MoS2/CdS eutectic clusters anchored
on rGO edge with enhanced hydrogen generation performance, Catal. Today 317
(
2018) 99–107, https://doi.org/10.1016/j.cattod.2018.01.023.
48] A. Shawky, M. Alhaddad, R.M.M. Mohamed, N.S. Awwad, H.A. Ibrahium,
Magnetically separable and visible light-active Ag/NiCo2O4 nanorods prepared by
a simple route for superior photodegradation of atrazine in water, Prog. Nat. Sci.
Mater. Int. 30 (2020) 160–167, https://doi.org/10.1016/j.pnsc.2020.01.021.
49] C. Xu, P. Ravi Anusuyadevi, C. Aymonier, R. Luque, S. Marre, Nanostructured
materials for photocatalysis, Chem. Soc. Rev. (2019), https://doi.org/10.1039/
C9CS00102F.
[
[
50] Y. Feng, M. Xu, H. Liu, W. Li, H. Li, Z. Bian, Charge separation and interfacial
selectivity induced by synergistic effect of ferroelectricity and piezoelectricity on
PbTiO3 monocrystalline nanoplates, Nano Energy 73 (2020) 104768, https://doi.
org/10.1016/j.nanoen.2020.104768.
51] A. Shawky, S.M. El-Sheikh, M.N. Rashed, S.M. Abdo, T.I. El-Dosoqy, M. Nageeb, S.
M. Abdo, T.I. El-Dosoqy, Exfoliated kaolinite nanolayers as an alternative
[
9