Applied physics letters journal.pdf

1. Vol.:(0123456789)
1 3
Applied Physics A (2020) 126:480
https://doi.org/10.1007/s00339-020-03664-6
Biosynthesis of silver‑doped nickel oxide nanoparticles and evaluation
of their photocatalytic and cytotoxicity properties
Samaneh Ghazal1
· Alireza Akbari1
· Hasan Ali Hosseini1
· Zahra Sabouri2
· Fatemeh Forouzanfar3
·
Mehrdad Khatami4
· Majid Darroudi5,6
Received: 28 March 2020 / Accepted: 22 May 2020 / Published online: 3 June 2020
© Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract
In the present study, Ag-doped nickel oxide nanoparticles (NiO-NPs) were synthesized through a sol–gel method using of
Cydonia oblonga plant extract as a new green stabilizing agent and employed Ni(NO3)2·6H2O and ­
AgNO3 as nickel and silver
sources, respectively. The synthesized Ag-doped NiO-NPs have been calcinated at 400 °C. Formation of Ag-doped NiO-NPs
was confirmed by the means of XRD, FESEM/EDAX, FTIR, TGA/DTG, UV–Vis spectrophotometry, and VSM techniques,
and effect of silver diluent doping on the photocatalytic properties of NiO-NPs was investigated. The XRD results have indi-
cated that the size of Ag-doped NiO-NPs has increased as the Ag concentration had been raised. The obtained particle size
in optimized conditions (Ag-doped 3%) has been reported to be about 9.24 nm. In the following, the photocatalytic activity
of Ag-doped NiO-NPs has investigated the degradation of Rhodamine B (RhB) dye, and according to the obtained results,
about 75% of RhB degraded under UV-light after 200 min. The cytotoxicity effect of Ag-doped NiO-NPs on PC12 cell lines
has been investigated by MTT assay, and the results showed that Ag-doped NiO-NPs inhibited cancer cells ­(IC50 ̴ 35 µg/ml).
Keywords Ag-doped NiO nanoparticles · Sol–gel · Cydonia oblonga extract · Photocatalytic · Cytotoxicity
1 Introduction
In the past few years, nanomaterials have gained prominence
in many industries because they contain interesting features
including thermal, mechanical, electrical, magnetic, and
optical properties [1]. The subject of "green chemistry" in
fields of nanoscience and nanotechnology has attracted the
attention of many since this method contains interesting fac-
tors such as reducing the involved costs in the production
of nanomaterials [2]. Moreover, green chemistry allows the
methods that are exerted for the production of nanoparticles
to be more favored than the ones used for natural products
and plant extracts [3, 4]. Next to being simple and inexpen-
sive, methods that involve the utilization of plant extracts
do not require any sophisticated tools and, at the same time,
contain their physicochemical properties that can be cat-
egorized as a separate class of nanomaterials [5]. Among
the different available techniques, the sol–gel method has
been used to control the size of metal oxide nanoparticles
in recent years [6, 7]. This procedure has also been recog-
nized as a practical and crucial method due to its simplicity
and lack of requiring precise equipments and devices. Fur-
thermore, the technique of sol–gel can provide easy control
over the morphology of oxide nanoparticles by regulating
the amount of involved hydrolysis and density reactions [8].
Recently, several researchers have focused on the sol–gel
synthesis of crystalline nanometal oxides, such as NiO, and
ZnO, due to their extraordinary properties and wide sur-
face areas [9–14]. There are many reports on the application
* Majid Darroudi
darroudim@mums.ac.ir; majiddarroudi@gmail.com
1
Chemistry Department, Payame Noor University,
19395‑4697 Tehran, Iran
2
Nanotechnology Research Center, Pharmaceutical
Technology Institute, Mashhad University of Medical
Sciences, Mashhad, Iran
3
Medical Toxicology Research Center, School of Medicine,
Mashhad University of Medical Sciences, Mashhad, Iran
4
NanoBioEletrochemistry Research Center, Bam University
of Medical Sciences, Bam, Iran
5
Nuclear Medicine Research Center, Mashhad University
of Medical Sciences, Mashhad, Iran
6
Department of Medical Biotechnology and Nanotechnology,
School of Medicine, Mashhad University of Medical
Sciences, Mashhad, Iran

2. S. Ghazal et al.
1 3
480 Page 2 of 8
of nickel oxide nanoparticles (NiO-NPs) in various fields,
including catalysts, magnetic materials, gas sensors, and
battery cathodes.[15–18]; however, pure NiO-NPs cannot
be directly exerted for industrial applications since they
contain poor optical properties due to the existing defects
such as oxygen vacancy or interstitial nickel [10]. As it is
known, doping is defined as the insertion of impurities into
a semiconductor crystal to change its conductivity [19]. This
process can also be expressed as importing impurities to
modify the properties of semiconductor crystals and their
number of electrons in the last layer, which determines the
type of applied doping [20]. Elements with 3 electrons are
included in the type p-doping valence layer, and the ones
with 5 electrons are categorized in the type n-doping capac-
ity layer [21]. According to the outcomes of this study, the
doping of NiO-NPs with a suitable element can be consid-
ered as a practical method for determining the designated
magnetic and optical properties [22]. Silver stands as one of
the elements that had been selected as a candidate for doping
with NiO because they contain certain features including
high solubility, large ion size, and low orbital energy [23].
Additionally, silver ions can be doped in NiO-NPs as an
acceptor because they contain excellent properties and hav-
ing the potential of being easily substituted [24]. In recent
times, many articles have been presented on the synthesis of
Ag-doped metal oxide nanoparticles and investigated pho-
tocatalytic effects in removing the organic dyes of aqueous
environments. In 2020, M.S. Dawoud et al. have presented a
study on photocatalytic properties of synthesized Ag-doped
­ZrO2 nanoparticles by a green method, and they have shown
degradation rate of Rhodamine B (RhB) to be about 95%
[25]. R. Singh et al. have studied the synthesis of Ag-doped
ZnO-NPs with enhanced photocatalytic properties in excel-
lent efficiency organic dyes removal of 90% [26]. Moreo-
ver, S. Iqbal et al. have presented a research work about
controlled synthesis of Ag-doped CuO nanoparticles with
a coating of poly (acrylic acid) for removal of methylene
blue (MB) [27]. Also, there are a large number reports on
the subject of Ag-doped metallic oxide nanoparticles such
as Ag-doped ­
TiO2, Ag-doped ZnO-NPs [28], and Ag-doped
­WO3-NPs [29]. In this work, we reported an environmentally
friendly alternative synthesis route to obtain Ag-doped NiO-
NPs using Cydonia oblonga extract as the stabilizing agent,
and Ni(NO3)2·6H2O and ­
AgNO3 salts as inorganic precursor.
The advantages of this method include being simple and
eco-friendly, requiring low-cost precursors, containing high
purity, and providing quantity products. Although research
has been done on the synthesis procedure and photocatalytic
effect of Ag-doped NiO-NPs, there is no article on the use of
Cydonia oblonga extract in the synthesis process that acts as
the capping agent in scientific researches (Table 1). There-
fore, one of the advantages of this work was usage the least
amount of Ag-doped NiO-NPs as catalyst (3.0 mg) under
low intensity of UVA light (11 W); in spite of these condi-
tions, the degradation percentage of RhB obtained about
75% under UVA light after 200 min. Also, the cytotoxic-
ity of Ag-doped NiO-NPs has been evaluated on PC12 cell
lines by the means of MTT assay. Moreover, the synthesized
nanoparticles have been characterized using FTIR, XRD,
UV–Vis, TGA/DTG, FESEM/EDAX, and VSM techniques.
2
Preparation of Ag‑doped NiO‑NPs
2.1 Materials and methods
The utilized chemicals and reagents in this study have
been ascertained to be of analytical grade. Ni(NO3)2·6H2O
(Merck, Germany), Cydonia oblonga, and ­
AgNO3 (Merck,
Germany) have been appointed as Ni source, capping agent,
and silver source, respectively, and Rhodamine B (RhB).
Subsequent to washing all of the involved glasswares with
­HNO3 and distilled water, we had them dried in an oven. It
should also be noted that double-distilled water has been
utilized for all of the performed experiments.
2.2 Preparation of Cydonia oblonga extract
Two hundred milliliters of distilled water has been added to
1.0 g of Cydonia oblonga seeds, and the prepared mixture
had been positioned at ambient temperature for 24 h. Then,
the obtained extract has been filtered and kept in a cool place
to be used during the synthesis process.
3
Synthesis of Ag‑doped NiO‑NPs
A modified sol–gel method has been used for the synthe-
sis of Ag-doped NiO-NPs ­
(AgxNi(1-x) O). Nickel (II) nitrate
hexahydrate (Ni(NO3)2.6H2O) was used as NiO source by
Table 1. Comparison of particle
size of the Ag-doped NiO-NPs
Silver percentage 2θ (deg.) FWHM (rad.) Diameter (nm) Identification
0% (Undoped NiO-NPs) 43.3 0.009 16.5 fcc (NiO)
1% 43.20 1.25 7.18 fcc (NiO+Ag)
3% 43.34 0.94 9.24 fcc (NiO+Ag)
5% 43.41 0.77 11.55 fcc (NiO+Ag)

3. Biosynthesis of silver-doped nickel oxide nanoparticles and evaluation of their photocatalytic…
1 3
Page 3 of 8 480
dissolution 14.54 g of Ni(NO3)2.6H2O in 100 ml of deion-
ized water at room temperature, silver nitrate ­
(AgNO3) was
utilized as the dopant source by variable percentages from
Ag (1, 3, and 5%), and Cydonia oblonga plant extract was
used as a reducing and stabilizing agent for synthesis of
Ag-doped NiO-NPs. The ­
AgNO3 solution was added into
(Ni(NO3)2.6H2O) solution with an addition (20 mL) of
Cydonia oblonga extract solution in a dropwise manner with
constant stirring, and the mixture solution was stirred for
5 min. Then, the solutions in the container are transferred to
an oil bath at 80 °C for 12 h. Afterward, obtained green gel
was dried at 100 °C for 6 h and in continue was calcinated
at 400 ℃ for 2 h (with a heating temperature of 5°/min). The
final product was the black colored powder of Ag-doped
NiO-NPs.
3.1 Characterization
The solution of biosynthesized Ag-doped NiO-NPs has been
confirmed by measuring the UV–Vis spectrum of the solu-
tion and the reaction mixture. The designated UV–Vis spec-
trum has been recorded on a double beam spectrophotometer
(Shimadzu, model UV-1800), which had ranged from 200 to
800 nm. The blank of this experiment has been set to be the
mixture of double-distilled water and the extract. We have
also distinguished the synthesized nanoparticles through the
employment of FTIR (Shimadzu, model FTIR 8400), XRD
(model XRD, D8-Advance Bruker), VSM (model MDKB),
FESEM/ EDAX (model TESCAN BRNO-Mira3), and TGA
(model BAHR STA 503) analyses.
4 Results and discussion
4.1 XRD Pattern
Figure 1 demonstrates the results of XRD pattern that has
been carried out in a conventional manner to study the struc-
tural and crystallographic information of Ag-doped NiO-
NPs, which had been obtained by using the extract of Cydo-
nia oblonga. The diffraction peaks that can be observed at 2θ
degrees (in the range of 35°–85°) are apparently indexed to
(111), (200), (220), (222), and (311), which have indicated
that the biosynthesized NiO-NPs had contained a face cubic
axis crystal structure (fcc). In accordance with the results,
the peak intensity has faced a decrease as the concentration
of Ag had been increased. No additional peaks were found
in this pattern representing the purity of the nanoparticles.
The average nanoparticles size was calculated through the
Scherrer equation (Eq. 1) that to be 16.5 nm for NiO and
7.18 to 11.55 nm for Ag–NiO (1%. 3%, and 5%), respec-
tively [30, 31].
where D stands as the particle size, B is the peak width at
half maximum intensity (FWHM) in radians, λ represents
the X-ray wavelength, and θ is the Bragg angle correspond-
ing to the diffraction-induced peak. The diameter of the
Ag-doped NiO-NPs increases when Ag concentration is
increased from 1 to 5% [32]. This increase in Ag-doping
size could be associated with an increase in internal struc-
tural weakens, which increases the rate of growth.[33].
The obtained results have been in agreement with standard
JCPDS # 1–1239 [34]. It can be taken from these facts that
the peak of nanoparticles is less intense and wider than con-
ventional materials, which consequently leads to the predic-
tion that the small crystallite size and high crystallinity of
synthesized Ag-doped NiO-NPs will have a significant effect
on biological activities [32].
4.2 FTIR
The FTIR spectra of synthesized bare NiO-NPs and Ag-
doped NiO-NPs by the usage of Cydonia oblonga extract
are displayed in Fig. 2. FTIR spectroscopy is a useful tool
for studying the functional groups of samples. The FTIR
spectrum, employed to examine the purity and structure of
(1)
D = k 𝜆 ∕ (𝛽 cos 𝜃)
Fig. 1 XRD patterns of biosynthesized bare and doped NiO-NPs

4. S. Ghazal et al.
1 3
480 Page 4 of 8
biosynthesized NiO-NPs and Ag-doped NiO-NPs, has not
displayed any distinctive peak through the checking range,
which suggests the purity of the green synthesizing method.
According to the FTIR spectrum, broadband observed at
range 3400 cm−1
, which related to the O–H stretching
vibrations of water molecules [3, 9], and observed band at
range 2357 cm−1
is because of the vibration of ­
CO2 mol-
ecules existing in the air [35]. Also, the detected band at the
range of 1616 cm−1
is related to the bending vibrations of
water molecules. Moreover, the observation band at range
450–850 cm−1
has been related to stretching vibrations of the
bond that exists between nickel and oxygen (Ni–O). Besides,
it can be observed that the peaks intensity has decreased by
increasing Ag concentration.
4.3 UV–Vis spectroscopy
Figure 3 shows the UV–Vis spectroscopy, of bare NiO and
Ag-doped NiO-NPs synthesized with Cydonia oblonga plant
extract via sol–gel method in wavelength of 200–800 nm.
[36, 37]. The absorption band observed in the range of 310
to 340 nm for NiO and NiO-NP, is due to electron transfer
from the Valence band to the conduction band [38, 39].
4.4 FESEM image of Ag‑doped NiO‑NPs
Figure 4 demonstrates the FESEM and EDAX and PSA
images of Ag-doped NiO-NPs with the percentages of 1%,
3%, and 5%, respectively. The influence of Ag doping on
the morphology and the surface of the NiO nanoparticles
has been examined with FESEM technique. From Fig. 4
a–k, it is detected that the surface morphology of all nano-
particles is shaped spherical and uniformly distributed.
The coverage categories with the Ag content increased
to 5%, indicating a higher compression of the nanopar-
ticles doped at 5% Ag. This result shows that Ag dop-
ing concentration has a main role in the separation of the
nanoparticles. Also, the distribution of nanoparticles was
determined by histogram curves (Fig. 4d, h, l and the aver-
age nanoparticles size increase from 98.99 to 177.79 nm
when Ag concentration is increased from 1 to 5%. This
result is in agreement with the results of the XRD pattern
and shows that the NiO nanoparticles do not agglomer-
ate. EDAX analysis (Fig. 4 (m, n, o)) confirmed the pres-
ence of oxygen, nickel and silver elements [40, 41]. The
comparisons have confirmed that our results are consistent
with the previous reports of Ag-doped NiO-NPs, which
had been synthesized by the usage of different plant spe-
cies [34].
4.5 VSM
Figure 5 demonstrates a hysteresis curve achieved at room
temperature for Ag-doped NiO-NPs (Ag 3%) in a range
of+10,000 to−10,000 Oe. The magnetic parameters have
also been included in the diagram. The saturation mag-
netization (Ms) of the Ag-doped NiO was found to be
0.0752 emu/g. No loops in VSM curve display antiferro-
magnetic behavior of Ag-doped NiO-NPs. Matching our
findings with those gained by G. Bharathy and P. Raji [42],
it was seen which the usage of Ag as capping agents con-
trols the size of nanoparticles and enhances the saturation
magnetization of the nanoparticles. However, the use of Ag
as capping agents leads to smaller size Ag-doped NiO 3%
(9.24 nm). It has been extremely established that the mag-
netic behavior of Ag-doped NiO depends on the size of the
nanoparticles [43–45].
Fig. 2 FTIR patterns of biosynthesized bare and doped NiO-NPs
Fig. 3 UV–Vis spectra of undoped and Ag-doped NiO-NPs

5. Biosynthesis of silver-doped nickel oxide nanoparticles and evaluation of their photocatalytic…
1 3
Page 5 of 8 480
Fig. 4 FESEM images (a–k),
PSA (d, h, l) and EDX (m–o) of
Ag-doped NiO

6. S. Ghazal et al.
1 3
480 Page 6 of 8
4.6 Photocatalytic activity
The photocatalytic process of Ag-doped NiO-NPs (Ag 3%)
has been studied using RhB decomposition exposed to the
UVA light at pH = 9. To perform this analysis, we had to
initially prepare 50 mL of RhB solution. Thereafter, the
RhB solution absorbance has been measured and recorded
through the usage of a UV device that contained a wave-
length of 200–800 nm [46]. As the next step, about 3 mg
of Ag-doped NiO-NPs has been added to the RhB solu-
tion. Then, the solution was stirred in the dark for 30 min,
and afterward, the solution absorbance was measured and
recorded. Finally, the sample has been exposed to UVA
light while being stirred at ambient temperature; mean-
while, the rate of adsorption and degradation has been
recorded in several steps and intervals of 20 min. The per-
centage of RhB degradation was calculated using Eq. 2,
which was about 75% [47–50].
(A0 = Absorbance of the solution before UV-irradia-
tion and At = Absorbance of the solution at any instant).
Figure 6a exhibits degradation of RhB using Ag-doped
NiO-NPs (Ag 3%) under UV-irradiation. Figure 6b dem-
onstrates the kinetic graph degradation of RhB as the
Ag-doped NiO-NPs (Ag 3%) have been exposed to UVA
light. In addition, it has been indicated by the results of
an experiment that the time required to complete the pho-
tocatalytic process is approximately 0 to 200 min interval
20 min. According to Eq. 3, the kinetics of the reaction
follows the pseudo-first-order model [51, 52].
(2)
Degradation(%) =
A0 − At
A0
× 100
where C0 stands for the concentration of solution before
light, Ct is the concentration of solution at any moment,
and Kobs is the observed rate constant that equaled
to−0.008 min−1
[53–55].
4.7 Cytotoxicity of Ag‑doped NiO‑NPs
The results of in vitro cytotoxicity studies in regard to the
Ag-doped NiO-NPs (Ag 3%) are illustrated in Fig. 7, which
has been attained subsequent to 24 h incubation Ag-doped
NiO-NPs with different concentrations in the range from 0
(control), 25, 50, 100, and 200 ppm. In the present study, to
evaluate the cytotoxicity of Ag-doped NiO-NPs was used of
the PC12 cell lines. That these cells were cultured in DMEM
(Dulbecco’s modified Eagle’s medium) containing 10%
FBS (fetal bovine serum) and 1% penicillin/streptomycin.
Cells were maintained at 37 ºC with 5% ­
CO2 in a humidi-
fied chamber. To determine the viability of cells treated via
Ag-doped NiO-NPs was used of MTT (3-(5,4-dimethylth-
iazol-2-yl)-5,2-diphenyl tetrazolium bromide) assay [56].
Cells were plated in 96-well plates (2×104
cells/well), and
cells were serum-starved for 24 h in culture medium supple-
mented with FBS. Cells were treated for 24 h with different
(3)
Ln
(
Ct
C0
)
= Kobst
Fig. 5 VSM curve of the Ag-doped NiO-NPs (Ag 3%)
Fig. 6 Degradation of RhB under UV-irradiation of Ag-doped NiO-
NPs (Ag 3%)

7. Biosynthesis of silver-doped nickel oxide nanoparticles and evaluation of their photocatalytic…
1 3
Page 7 of 8 480
concentrations of Ag-doped NiO-NPs. The culture medium
was interchanged with MTT component (50 µL, 5 mg/mL)
to each well. After 4 h incubation at 37 °C, the medium
was replaced by 200 µL DMSO. The absorbance of each
well was measured at 540 nm using a spectrophotometer.
The cytotoxicity results of Ag-doped NiO-NPs at various
concentrations are presented in Fig. 7. The concentration
of nanoparticles that are showing a 50% reduction in cell
viability is considered to be ­
IC50 (half maximal inhibitory
concentration). The results showed that Ag-doped NiO-NPs
inhibited cancer cells with ­
IC50 about 35 ppm. According
to the results, Ag-doped NiO-NPs show a high cytotoxicity
effect [57–59].
5 Conclusion
This study contains the obtained data on Ag-doped NiO-NPs
with different percentages (e.g., 1, 3, and 5%) of Ag that
has been synthesized by the utilization of Cydonia oblonga
extract and performed via a sol–gel method at the calcina-
tion temperature of 400 °C. In the following, we have char-
acterized the structure of the nanoparticles and determined
their cytotoxicity effects as well. They have also been sub-
jected to various analyses, including XRD, VSM, FTIR, and
UV–Vis, respectively, while the size of synthesized nano-
particles has been confirmed and distinguished through the
FESEM images. According to the analyzed diffusion and
scattered XRD peaks, the diameter of the Ag-doped NiO-
NPs increases when Ag concentration is increased from
1 to 5%, which this increase in Ag-doping size could be
associated with a rise in internal structural weakens, which
increases the rate of growth. Moreover, according to the
results of toxicity studies, Ag-doped NiO-NPs were shown
a high cytotoxicity effect upon PC12 cell line.
Acknowledgment The technical support of this project has been pro-
vided by Payame Noor University of Mashhad and Mashhad University
of Medical Sciences based on the thesis of Mrs. S. Ghazal.
References
1. Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F.
Kim, H. Yan, Adv. Mater. 15(5), 353 (2003)
2. Q. Li, L.-S. Wang, B.-Y. Hu, C. Yang, L. Zhou, L. Zhang, Mater.
Lett. 61(8–9), 1615 (2007)
3. R. Teimuri-Mofrad, R. Hadi, H. Abbasi, E. Payami, S. Neshad, J.
Organomet. Chem. 899, 120915 (2019)
4. Z. Sabouri, A. Akbari, H.A. Hosseini, M. Darroudi, J. Mol. Struct.
1173, 931 (2018)
5. M.A. Iqbal, R.A. Haque, W.C. Ng, L.E.H. Hassan, A.M.S.A.
Majid, M.R. Razali, J. Organome.t Chem. 801, 130 (2016)
6. Z. Sabouri, A. Akbari, H.A. Hosseini, A. Hashemzadeh, M. Dar-
roudi, J. Clust. Sci. 30(6), 1425 (2019)
7. A.S. Danial, M.M. Saleh, S. Salih, M. Awad, J. Power Sour. 293,
101 (2015)
8. M. Najjar, H.A. Hosseini, A. Masoudi, A. Hashemzadeh, M. Dar-
roudi, Res. Chem. Intermed. 46, 2155 (2020)
9. M.M. Ba-Abbad, A.A.H. Kadhum, A.B. Mohamad, M.S. Takriff,
K. Sopian, J. Alloys Compd. 550, 63 (2013)
10. Z. Sabouri, A. Akbari, H.A. Hosseini, A. Hashemzadeh, M. Dar-
roudi, J. Mol. Struct. 1191, 101 (2019)
11. M.T. Ramesan, K. Nushhat, K. Parvathi, T. Anilkumar, J. Mater.
Sci. Mater. Electron. 30, 13719 (2019)
12. M.T. Ramesan, V. Santhi, Compos. Interfaces 25, 725 (2018)
13. M.T. Ramesan, V. Nidhisha, P. Jayakrishnan, Polym. Int. 66, 548
(2017)
14. M.T. Ramesan, C. Siji, G. Kalaprasad, B. Bahuleyan, M. Al-
Maghrabi, J. Polym. Environ. 26, 2983 (2018)
15. M.T. Ramesan, V. Santhi, J. Mater. Sci. Mater. Electron. 28(24),
18804 (2017)
16. M. Alagiri, S. Ponnusamy, C. Muthamizhchelvan, J. Mater. Sci.
Mater. Electron. 23, 728 (2012)
17. Y. Wu, Y. He, T. Wu, T. Chen, W. Weng, H. Wan, Mater. Lett.
61(14–15), 3174 (2007)
18. X. Xin, Z. Lü, B. Zhou, X. Huang, R. Zhu, X. Sha, Y. Zhang, W.
Su, J. Alloys. Compd. 427(1–2), 251 (2007)
19. S. Ghazal, A. Akbari, H.A. Hosseini, Z. Sabouri, F. Forouzanfar,
M. Khatami, M. Darroudi, J. Mol. Struct. 1217, 128378 (2020)
20. H. Snaith, T. Leijtens A. Abate and A. Sellinger (2018) Google
Patents
21. M.S. Shatalov, R. Gaska, J. Yang and M. Shur (2016) Google
Patents
22. S. Islam, V. Protasenko, S. Rouvimov, J. Verma, H. Xing and D.
Jena (2015) 73rd Annual Device Research Conference (DRC),
Columbus, OH, pp. 67
23. T. Zhang, X. Li, T. Pu, Q. Wang, S. Cheng, L. Li, Mater. Sci.
Semicond. Process. 105, 104733 (2020)
24. A. Miri, M. Sarani, M.R. Bazaz, M. Darroudi, J. Spectrochim.
Acta Part A Mol. Biomol. Spectrosc. 141, 287 (2015)
25. M.P. Noghabi, M.R. Parizadeh, M. Ghayour-Mobarhan, D. Taher-
zadeh, H.A. Hosseini, M. Darroudi, J. Mol. Struct. 1146, 499
(2017)
26. T.M. Dawoud, V. Pavitra, P. Ahmad, A. Syed, G. Nagaraju, J. King
Saud Univ. Sci. 32(3), 1872 (2020)
27. R. Singh, P. Barman, D. Sharma, J. Mater. Sci. Mater. Electron.
28(8), 5705 (2017)
28. S. Iqbal, M. Javed, A. Bahadur, M.A. Qamar, M. Ahmad, M.
Shoaib, M. Raheel, N. Ahmad, M.B. Akbar, H. Li, J. Mater. Sci.
Fig. 7 Cytotoxicity investigation of Ag-doped NiO-NPs (Ag 3%)
using MTT assay

8. S. Ghazal et al.
1 3
480 Page 8 of 8
Mater. Electron. (2020). https​://doi.org/10.1007/s1085​4-020-
03377​-9
29. G.Y. Nigussie, G.M. Tesfamariam, B.M. Tegegne, Y.A. Weld-
emichel, T.W. Gebreab, D.G. Gebrehiwot and G.E. Gebremichel
(2018) Int. J. Photoenergy 5927485
30. S.M. Harshulkhan, K. Janaki, G. Velraj, R.S. Ganapathy, S.
Krishnaraj, J. Mater. Sci. Mater. Electron. 27(4), 3158–3163
(2016)
31. B. Anandan, V. Rajendran, Mater. Sci. Semicond. Process. 14(1),
43 (2011)
32. Z. Sabouri, N. Fereydouni, A. Akbari, H.A. Hosseini, A.
Hashemzadeh, M.S. Amiri, R.K. Oskuee, M. Darroudi, Rare Met.
(2019). https​://doi.org/10.1007/s1259​8-019-01333​-z
33. D. Sahu, N. Panda, B. Acharya, A. Panda, Optical Mater. 36(8),
1402 (2014)
34. L. Ouarez, A. Chelouche, T. Touam, R. Mahiou, D. Djouadi, A.
Potdevin, J. Lumin. 203, 222 (2018)
35. K. Basavalingiah, S. Harishkumar, G. Nagaraju, D. Rangappa, SN
Appl. Sci. 1(8), 935 (2019)
36. K. Sathishkumar, N. Shanmugam, N. Kannadasan, S. Cholan, G.
Viruthagiri, Mater. Sci. Semicond. Process. 27, 846 (2014)
37. M. Darroudi, A.K. Zak, M.R. Muhamad, R. Zamiri, Res. Chem.
Intermed. 41, 4587 (2015)
38. K. Shameli, M.B. Ahmad, W.M.Z.W. Yunus, N.A. Ibrahim, R.A.
Rahman, M. Jokar, M. Darroudi, Int. J. nanomed. 5, 573 (2010)
39. A. Berkowitz, R. Kodama, S.A. Makhlouf, F. Parker, F. Spada, E.
McNiff Jr., S. Foner, J. Magn. Magn. Mater. 196, 591 (1999)
40. M. Kazemi, A. Akbari, H. Zarrinfar, S. Soleimanpour, Z. Sabouri,
M. Khatami, M. Darroudi, J. Inorg. Organomet. Polym. Mater.
(2020). https​://doi.org/10.1007/s1090​4-020-01462​-4
41. J. Najim, J. Rozaiq, Int. Lett. Chem. Phys. Astron. 10, 137 (2013)
42 Z. Sabouri, A. Akbari, H.A. Hosseini, M. Khatami, M. Darroudi,
Polyhedron 178, 114351 (2020)
43. G. Bharathy, P. Raji, Int. J. Chem. Tech. Res. 7, 1559 (2015)
44. R. Suresh, V. Ponnuswamy, C. Sankar, M. Manickam, S. Venkate-
san, S. Perumal, J. Magn. Magn. Mater. 441, 787 (2017)
45. S. Chatterjee, R. Maiti, M. Miah, S.K. Saha, D. Chakravorty, ACS
omega 2, 283 (2017)
46. Z. Sabouri, A. Akbari, H.A. Hosseini, M. Khatami, M. Darroudi,
Bioprocess Biosyst. Eng. (2020). https​://doi.org/10.1007/s0044​
9-020-02315​-7
47. C. Wang, S. Luo, C. Liu, X. Liu, C. Chen, Inorg. Chem. Commun.
114, 107842 (2020)
48. M.A. Chamjangali, S. Boroumand, J. Brazilian Chem. Soc. 24(8),
1329 (2013)
49. I. Arabatzis, T. Stergiopoulos, D. Andreeva, S. Kitova, S. Neo-
phytides, P. Falaras, J. catal. 220(1), 127 (2003)
50. N. Khandannasab, Z. Sabouri, S. Ghazal, M. Darroudi, J. Mol.
Struct. 1203, 127411 (2020)
51. B.N. Rashmi, S.F. Harlapur, B. Avinash, C.R. Ravikumar, H.P.
Nagaswarupa, M.R. Anil Kumar, K. Gurushantha, M.S. Santosh,
Inorg. Chem. Commun. 111, 107580 (2020)
52. Z. Sabouri, A. Akbari, H.A. Hosseini, A. Hashemzadeh, M. Dar-
roudi, J. Clust. Sci. 30, 1425 (2019)
53. S. Nemati, H.A. Hosseini, A. Hashemzadeh, M. Mohajeri, Z. Sab-
ouri, M. Darroudi, R.K. Oskuee, Mater. Res. Expr. 6(12), 125016
(2019)
54. D. Malwal, P. Gopinath, Environ. Sci. Nano 2(1), 78 (2015)
55. M. Alikhani, M. Hakimi, K. Moeini, V. Eigner, M. Dusek, J.
Inorg. Organomet. Polym. Mater. (2020). https​://doi.org/10.1007/
s1090​4-020-01442​-8
56. M. Darroudi, Z. Sabouri, R. Kazemi Oskuee, A. Khorsand Zak,
H. Kargar, M.H.N.A. Hamid, Ceram. Int. 39(8), 9195 (2013)
57. E. Nourmohammadi, R.K. Oskuee, L. Hasanzadeh, M. Mohajeri,
A. Hashemzadeh, M. Rezayi, M. Darroudi, Ceram. Int. 44(16),
19570 (2018)
58. M. Darroudi, Z. Sabouri, R. Kazemi Oskuee, H. Kargar, H.A.
Hosseini, Nanomed. J. 1(2), 88 (2014)
59. M. Darroudi, Z. Sabouri, R. Kazemi Oskuee, A.K. Zak, H. Kargar,
M.H.N.A. Hamid, Ceram. Int. 40(3), 4827 (2014)
Publisher’s Note Springer Nature remains neutral with regard to
jurisdictional claims in published maps and institutional affiliations.