Fabrication and study of UV-shielding and photocatalytic...

Scientia Iranica F (2016) 23(6), 3135{3144

Sharif University of TechnologyScientia Iranica

Transactions F: Nanotechnologywww.scientiairanica.com

Fabrication and study of UV-shielding andphotocatalytic performance of uniform TiO2/SiO2core-shell nano�bers via single-nozzleco-electrospinning and interface sol-gel reaction

O. Nakhaeia;b, N. Shahtahmassebia;b;�, M. Rezaee Roknabadia and M. Behdania

a. Department of Physics, School of Science, Ferdowsi University of Mashhad, Mashhad, P.O. Box 9177948974, Iran.b. Nano Research Center, Ferdowsi University of Mashhad, Mashhad, P.O. Box 9177948974, Iran.

Received 13 December 2015; received in revised form 20 June 2016; accepted 14 August 2016

KEYWORDSNano�bers;Core-shell structures;Electrospinningmethod;Photocatalyticactivity;UV-shieldingperformance.

Abstract. One-dimensional TiO2/SiO2 core-shell nano�bers were fabricated using asingle-nozzle co-electrospinning process with phase-separated, mixed polymer compositesolution. The core and shell were composed of Polyvinylpyrrolidone (PVP) and Poly-acrylonitrile (PAN) polymers with uniform distribution of TiO2 and SiO2 nanoparticles(NPs), respectively. The NPs were synthesized via sol-gel reaction, simultaneously, in therespective polymer solutions. The morphologies and structures of the fabricated TiO2/SiO2

core-shell nano�bers were investigated by XRD, FTIR, SEM, EDS, and TEM images. Thein uences of di�erent amounts of TiO2 and SiO2 precursors on the photocatalytic and UV-shielding performance of TiO2/SiO2 core-shell nano�bers were studied. Photocatalyticactivity of the nano�bers was evaluated by observing photo-degradation of Methyl Orange(MO) aqueous solution under irradiation of ultraviolet (UV) light. Our results forthe TiO2/SiO2 core-shell nano�bers indicate good potential for superior applications inphotocatalytic and UV shielding devices.© 2016 Sharif University of Technology. All rights reserved.

1. Introduction

Photochemical oxidations for the removal of organiccontaminants by Semiconductor Metal Oxides (SMOs)have been widely studied in the literatures [1-6].Among these, TiO2 NPs have been more exten-sively studied for their use in photovoltaic cells, elec-trochromic materials, photocatalysis, and waste watertreatments [5]. Super-�ne titanium dioxide particles inthe nanometer scale with high transparency have alsobeen used for shielding against a broad range of UVwavelengths [6].

Many studies have con�rmed that UV radiation

*. Corresponding author. Fax: +98 51 38805000E-mail address: [email protected] (N. Shahtahmassebi)

could cause serious damages to eye, skin, immunesystem, and biological genomes of human being [7,8].Therefore, the exploration of UV-shielding materialsis a hot research topic in materials science and hasattracted considerable research interests.

Titanium dioxide is a wide-bandgap (3.2 eV)semiconductor that can absorb UV light and has beenwidely used in heterogeneous photocatalysis to degradeorganic pollutants in water and air [9]. TiO2 NPshave become a promising photocatalyst due to theirchemical stability, low cost, and high photocatalyticactivity [9]. However, the major limitations to theircommercial applications are the nature of aggregation,di�culty in recycling, and recovery of TiO2 NPs. Toovercome these di�culties, e�orts have been madeto fabricate one-Dimensional (1D) structures. 1D

3136 O. Nakhaei et al./Scientia Iranica, Transactions F: Nanotechnology 23 (2016) 3135{3144

nanocomposites have many excellent characteristicssuch as faster electron transport, enhanced light ab-sorption and scattering, and larger surface area becauseof 1D geometry [10].

A number of recent studies have focused on thepreparation of polymeric hybrid �bers by incorporatingsome wide-bandgap semiconductor �llers like TiO2,ZnS, and ZnO into the polymer matrix. The e�ectof the incorporated polymers is that, in addition tohaving a high transparency throughout the visiblerange, they can strongly absorb the deep-ultraviolet(DUV) wavelengths less than 300 nm [11].

Kwon et al. proved that the UV-blocking e�-ciency of 1D TiO2 nanowires and nanotubes was higherthan that of commercial TiO2 NPs, which might be dueto their enhanced photo-scattering capability caused bylarge surface area and their speci�c band structure [12].

Extensive research has been conducted to developpolymer-matrix composites containing SiO2 NPs �llers.For instance, formation of SiO2 NPs incorporatedinto polyethylacrylic-acid (PEAA) resin by a meltblending process improves the UV-shielding ability. Si-ZnO/PEAA showed about 97% UV-shielding activity,which is more than that of ZnO/PEAA [7]. Also,the studies of Chao-Hua Xue et al. indicated thatsilica NPs not only improved the UV-shielding propertybut also upgraded the UV-durability of the superhydrophobicity on the textiles [13]. Moreover, silica(SiO2) fume enhanced Electromagnetic Interference(EMI) shielding e�ectiveness of multi-walled carbonnanotube/cement composites [14].

Considering the above studies, SiO2 NPs in PANas a shell and TiO2 in PVP as a core, i.e. TiO2/SiO2core-shell nano�bers, are expected to exhibit enhancedUV-shielding and photocatalytic activities.

PAN is recognized as the most important andpromising precursor for carbon �ber. There are numer-ous advantages for PAN �bers, including high degreeof molecular orientation, and higher melting point andthermal stability [15]. It is also possible to blend thePAN with other polymers like PEG (poly ethyleneglycol) and PVP [15].

In this work, TiO2/SiO2 core-shell nano�berswere synthesized using the co-electrospinning method.Recently, the technique of electrospinning has pro-vided an innovative approach for the straightforwardfabrication of 1D nanomaterial with diameter typi-cally ranging from tens to hundreds of nanometers.Electrospinning has become one of the inexpensive,simple, and convenient techniques that use electrostaticforce to produce polymeric, ceramics, and compositecontinuous ultra�ne �bers [16].

In the present study, we focused on synthesizing1D core-shell nano�bers and using PAN and PVP poly-mers for improving UV-shielding and photocatalyticproperties. Such special structures incorporate surface

modi�cation of TiO2 nano�bers by SiO2 nano�bers andprovide a better adsorption, larger speci�c surface area,and enhancement in the photocatalytic activity.

Meanwhile, TiO2/SiO2 nano�bers were fabricatedwith di�erent amounts of TBOT and TEOS (precur-sors) for investigating the role of density of NPs in thephotocatalytic activity and UV-shielding e�ciency. Inaddition, the UV shielding performance of TiO2/SiO2core-shell nano�bers was compared with those of pureSiO2 and TiO2 NPs and our results indicated thesuperiority of our samples in UV-shielding and pho-tocatalytic applications.

2. Experimental

2.1. MaterialsAll chemicals were of analytical grade and utilizedwithout further puri�cation. Tetraethylorthosilicate(TEOS), TBOT (Tetra-n-butyl-orthotitanate), andacetic acid (glacial) were procured from Merck Co.Polyvinylprrolidone (PVP, Mw = 130000) and Poly-acrylonitrile (PAN, Mw=150000) were purchased fromSigma Aldrich Co. and N , N -dimethylformamide(DMF) was obtained from Scharlau Co. Moreover,TiO2 NPs from TECNAN Co. were used.

2.2. Synthesis procedure2.2.1. Preparation of precursorsTo prepare the precursor solutions for co-electrospin-ning, a sol-gel chemical route was applied. First, asolution with di�erent amounts of TEOS and aceticacid was added into 0.7 g of PAN that was dissolvedin 5 mL of DMF at room temperature and stirred for6 h to obtain sheath solution. Meanwhile, di�erentamounts of TBOT and acetic acid were added into 0.7 gof PVP and 5 mL of DMF under vigorous magneticstirring at 60�C to prepare core solution. Core solutionwas prepared after being rapidly stirred for 6 h.Finally, equal amounts of two solutions were mixed andmagnetically stirred until a homogeneous solution wasobtained for the electrospinning process. The amountof chemicals that were used for synthesizing varioussamples of TiO2/SiO2 core-shell nano�bers (a, b, andc) are listed in Table 1.

2.2.2. Single-nozzle co-electrospinning processThe strategy for fabrication of TiO2/SiO2 core-shellnano�bers, which basically used single-nozzle co-electrospinning and interface sol-gel reaction, is illus-trated in Figure 1(a). Five components (PAN-TEOSand PVP-TBOT-DMF) were required to make the ini-tial core-shell nano�bers separated as continuous anddiscontinuous phases due to the incompatibility of thetwo polymers in the mixed solution [17]. The resultingviscous hybrid solution was injected into the electro-spinning apparatus by a syringe. In electrospinningprocess, the high voltage was held at 13 kV, the ow

O. Nakhaei et al./Scientia Iranica, Transactions F: Nanotechnology 23 (2016) 3135{3144 3137

Table 1. Chemicals used for synthesis of TiO2/SiO2 core-shell nano�bers.

SampleTEOS(mL)

(shell solution)

TBOT(mL)

(core solution)

Acetic acid(mL)

added to core

Acetic acid(mL)

added to shell

PVP(g)

(core polymer)

PAN(g)

(shell polymer)a 0.7 0.5 1.5 1 0.7 0.7b 0.8 0.6 1.5 1 0.7 0.7c 0.9 0.7 1.5 1 0.7 0.7

Figure 1. (a) The strategy of fabrication of TiO2/SiO2 core-shell nano�bers. (b) Photographic image of the �nal productthat was collected on the aluminum foil.

rate of the syringe pump was 0.4 mL/h, the distancebetween the nozzle and the collector was 14 cm, anddrum linear and rotary speeds were 220 mm/min and300 rpm, respectively. The �bers were collected onan aluminum foil and dried at 300�C for 1 h. The�nal product can be seen in Figure 1(b). Core-shellnano�bers were fabricated by using electrospinningdevice model (eSpinner NF CO-N/VI) from AsianNanostructures Co, (ANSTCO).

2.3. Photocatalytic activity measurementsTo evaluate the photocatalytic performance of TiO2/SiO2 nanocomposite nano�bers, Methyl Orange (MO)was used as target organic pollutant for catalyticdegradation reaction under UV light irradiation, whichwas generated by a 125-W mercury lamp. In a typicalprocedure, for each sample, 10 mL of solution of MBwith 20 mg/L of concentration was taken into the vesseland 20 mg of photocatalyst (nano�bers and TiO2 NPs)was added into the above dye solution. During thephotoreaction, the samples were collected at regularintervals (20 min) and centrifuged to remove the pho-tocatalyst. The concentrations of the target organicsolution before and after degradation were measuredby using a UV-Vis spectrometer (UVD2950). Theadsorption capability (qe) and degradation e�ciency(D) of the samples were calculated using the followingequations [18,19]:

qe =(C0 � Ce)V

W; (1)

D =Ce � CtCe

� 100 =Ae �AtAe

� 100; (2)

where C0 is the initial concentration of target solution(mg/L); Ce is equilibrium concentration after degra-dation/adsorption (mg/L); V is the volume of targetsolution (mL); W is the weight of the synthesizedphotocatalyst (mg); and, �nally, A0, Ae, and At arethe corresponding absorbances of dye at the original,equilibrium, and at the time t minutes later, respec-tively.

2.4. CharacterizationThe crystallographic structure of the sample was in-vestigated using X-Ray Di�raction (XRD) AdvancedBruker model D8 (using Cu K� line � = 0:15406 nm).X-ray intensity was determined in the ranges of 20� <2� < 80� with a 0:5� step size.

Fourier transform infrared (FTIR) spectra wererecorded by AVATAR-370-FTIR Thermonicolet FTIRspectrometer.

Transmission Electron Microscopy (TEM) andScanning Electron Microscopy (SEM) micrographswere used to observe diameters and morphology ofthe �bers. TEM images of core-shell nano�bers wererecorded using a Leo 912AB TEM. The morphologiesof the nanocomposite nano�bers were recorded using aLeo 1450VP SEM. For optical studies, the absorptionspectra of nano�bers were measured by a UV-Visspectrophotometer (UVD2950).

3. Results and discussion

3.1. Morphology of electrospun nano�bersSEM micrographs of TiO2/SiO2 core-shell nano�bers(a, b, and c are the samples that were explained insynthesis procedure) are shown in Figure 2.


Figure 2. SEM micrographs of TiO2/SiO2 core-shell nano�bers: (a) Sample a; (b) sample b; (c) sample c; (d) samples10000 magni�cation; and (e) enlarged SEM micrograph of TiO2/SiO2 core-shell nano�bers.

As seen in Figure 2, very uniform and smooth�bers without any beads were formed with average di-ameter ranging from 358-550 nm, which is in very goodagreement with reported data in the literature [10,20].

The average diameters of TiO2/SiO2 nano�berswere measured by the Image Tool 3.00 software. Theaverage diameters for di�erent samples are summarizedin Table 2.

Also, Core-shell structure of nano�bers can beclearly seen in Figure 2(d) and (e). The SEM mi-crograph with 10000 magni�cations was chosen andenlarged. Enlarged SEM micrograph from core-shell

Table 2. Full diameter of TiO2/SiO2 core-shellnano�bers.

Sample a b c

Diameter (nm) 530 550 358

structure shows formation of thick core and very �neshell.

For further morphological analysis, TEM micro-graph was recorded. A TEM micrograph of core-shell nano�bers is displayed in Figure 3 that con�rmsthe successful formation of core-shell structure. TEM


Figure 3. TEM micrograph of TiO2/SiO2 core-shellnano�bers.

image shows that very thick core and very �ne shell areformed successfully (Figure 3).

The Energy-Dispersive X-ray Spectroscopy (EDS)analysis was employed to determine chemical com-position in the samples where the resultant spectraindicated the presence of Si, Ti, O, and C elementsin all samples (Figure 4). In all spectra, the presenceof Al and Au peaks was attributed to the presence ofaluminum foils that were used for collecting �bers, andAu peaks were related to the gold used for coating thesample surface during its preparation steps for SEMcharacterization. Figure 4(a) shows very weak Si andTi peaks due to a small amount of precursors (TEOS,TBOT) that was used in synthesis process, and strongC peak is due to PAN and PVP polymers. Figure 4(b)and (c) illustrate stronger Ti and Si peaks that verifyexistence of more amounts of Si and Ti elements in the�bers.

FTIR spectroscopy studies have been carried outto elucidate the Ti-O and Si-O bonds in the samples(a, b, and c). In all FTIR spectra (Figure 5),strong absorption peak within 550-800 cm�1, whichis the typical adsorption in anatase phase of TiO2,is associated with the stretching vibrations of the Ti-O-Ti bonds [19]. The absorption band at 1095 and1063 cm�1 con�rms asymmetric stretching frequencyof Si-O-Si linkage and polymeric Si-O vibrations [21].Figure 6(a) and (b) show chemical structure of PANand PVP polymers. PAN �bers have many peaks,which are related to the existence of CH2, C�N,C=O, C-O, and C-H bonds. Thus, the absorptionpeaks at 1256, 1388, 1694, 1723, and 2900 cm�1 arerelated to C-O-C, C-C, C-O, C=O, and C-H bonds,respectively [22].

Upon oxidation, the nitrile groups (C�N) in PANchain intend to cyclize in the form of {C=N{C=N{.Thus, strong peaks at 1670-1673 cm�1 and weak peaks

Figure 4. EDS spectra of (a) sample a, (b) sample b,and (c) sample c.

at about 2240 cm�1 are related to existence of C-N andC�N bonds, respectively [23].

The peaks at 3491 cm�1 in all the spectra corre-spond to the stretching vibrations of the {OH group ofthe absorbed water molecules and the surface hydroxylson the TiO2 particles [24]. In addition, FTIR spectrumshows that with increasing the amount of TEOS andTBOT in the synthesis, more intense IR bands areobserved.

Crystal structure and phase purity of the synthe-sized nano�bers were investigated using X-Ray Di�rac-tion (XRD). As seen in Figure 7, XRD pattern of core-shell nano�bers demonstrates that the 1D core/shellnano�bers are made up of anatase TiO2 core andamorphous SiO2 shell. The broad peaks indicatethat nano-crystalline nature of TiO2 NPs has formedsuccessfully. The average crystalline size of the NPs


Figure 5. FTIR spectra of (a) sample a, (b) sample b,and (c) sample c.

Figure 6. Chemical structures of (a) PAN polymer and(b) PVP polymer.

Figure 7. XRD pattern of TiO2/SiO2 core-shellnano�bers.

in the polymer matrix was calculated using Scherrer'sequation [25,26]. Crystalline sizes were calculated formajor peaks, i.e. (204) and (004), whose results aresummarized in Table 3.

3.2. UV-shielding and photocatalytic activityof TiO2/SiO2 core-shell nano�bers

Recently, many attempts have focused on synthesizingof nanostructures with high UV-shielding e�ciency.Di�erent shapes of SiO2 NPs showed high UV shielding

Table 3. The obtained structural parameters of XRDanalysis for major peaks.

hkl 2�(deg.)

FWHM(deg.)

DXRD(nm)

204 62.767 2.053 4.8004 38.007 1.576 5.7

e�ciency. For example, mesoporous silica nanospheresre ect more than 90% of the UV and visible light in thewide range of 240-800 nm and more than 70% of theUV light shorter than 240 nm, which are signi�cantlyhigher than those for the bulk silica [12,27].

To study UV-shielding ability of core-shellTiO2/SiO2 nano�bers, UV-Vis absorption spectra ofall the samples (a, b, and c), pure SiO2, and commer-cial TiO2 NPs were measured. (Pure anatase/rutileTiO2 and SiO2 NPs with 10 nm of average crystallinesize were used for comparison.)

As shown in Figure 8(a), SiO2/TiO2 core-shellnano�bers with the highest SiO2 and TiO2 precursors(sample c) show the best UV-shielding performance,especially in UV and DUV wavelengths. UV-shieldingactivities of core-shell nano�bers and pure samples inan increasing order are as follows: a < SiO2 NPs < b< TiO2 NPs < c.

For better understanding, UV-Vis transmittancespectra of the above samples were also measured(Figure 8(b)). Transmitting e�ciency of sample cin UV and DUV (ranging from 210 to 250 nm)wavelengths is approximately zero, demonstrating thatsuch nanocomposite nano�bers have excellent UV-prevention performance superior to the commerciallyTiO2 NPs and other core-shell nano�bers (samples band c). TiO2/SiO2 core-shell structure shields all UVand DUV rays completely.

Photo-degradation experiments on MO were car-ried out for the purpose of studying the degradationcapability of the novel photocatalyst on the dyes underUV light irradiation. The degradation mechanism canbe interpreted as the following equations:

TiO2 + h� ! TiO2�eCB + h+

VB�; (3)

h+VB + MB! Oxidation of MO; (4)

h+VB + H2O! H+ + �OH; (5)

h+VB + OH� ! �OH; (6)

eCB +O ! �O�2 ; (7)

�O�2 + MO! MO�OO�; (8)

�OH + MO! degradation of MO: (9)


Figure 8. (a) UV-Vis absorbance and (b) UV-Vistransmittance spectra of TiO2/SiO2 core-shell nano�bers,pure TiO2, and SiO2 NPs.

In Eqs. (3)-(9), h+VB and eCB occupy an important

position in degradation of organic molecules. Photogeneration of electron-hole pairs between the conduc-tion (CB) and Valence Bands (VB) due to excitationof TiO2 under UV light illumination is responsible forthe production of hydroxyl radicals and superoxideanion [28]. The process of photocatalytic degradationMO is the same as destroying contamination under UVlight in the presence of photocatalyst samples.

Absorption changes spectra of MO aqueous so-lution in the presence of core-shell nano�bers (sam-ples a, b, and c) under UV-light irradiation can beseen in Figure 9. Spectra were recorded within thetime interval of 0-60 min. It was observed that theintensity of the absorption peak of MO decreases asthe irradiation time increases. Sample c shows thegreatest decrease in absorbance of MO solution within1h and best photo-degradation activity. For further

Figure 9. Absorption changes spectra of MO aqueoussolution under di�erent UV-irradiation times for (a)sample a, (b) sample b, and (c) sample c.

photocatalyst analysis, degradation rate of MO underUV irradiation was calculated.

Figure 10 demonstrates the rate of MO degra-dation as a function of time in the presence of pho-tocatalyst, TiO2/SiO2 core-shell nano�bers under UVirradiation. The degradation rate (%) was calculated as


Figure 10. Photocatalytic degradation rate of MO underUV-light irradiation of TiO2/SiO2 core-shell nano�bers.

(C0�C=C0)�100, where C0 is the initial concentrationand C is the concentration at time t [28]. A fastdecomposition of MO dye with a rate of 90.3% has beenobserved within 60 min. The best photocatalytic ac-tivity (90.3%) was reached for sample c within 60 min.It can be seen that the photocatalytic e�ciencies ofthese samples vary in the following order: sample a< sample b < sample c. The photocatalytic testsfor TiO2 NPs were also carried out for comparison ofcore-shell nano�bers. Figure 11(a) and (b) show UV-Vis spectrum and degradation rate of MO under UVradiation of TiO2 NPs, respectively. It can be clearlyseen in Figure 11(b) that degradation rate of MOreached about 50% within 60 min that is signi�cantlyless than degradation rate of MO in the presenceof TiO2/SiO2 nano�bers with the highest precursors(sample c).

Sample a shows very weak photocatalytic activityunder UV light radiation; degradation rate of MO forsample a reached only 28% within 60 min because ofthe slight amount of TiO2 and SiO2 in TiO2/SiO2 core-shell structure.

1D core-shell structure of nano�bers overcomesthe aggregation nature, di�culty of recycling, andrecovery problem of TiO2 NPs, and shows excellentphotocatalytic activity. Herein, fast photo generation,charge separation, and relatively slow charge recom-bination occur, which signi�cantly enhance the pho-tocatalytic activity of the as-prepared photocatalystsamples [29].

SiO2 NPs are one of the strongest known ma-terials in nature that strengthen the stability of thecore-shell nano�bers; SiO2 NPs in the shell part ofTiO2/SiO2 core-shell structures with increasing surfacearea of the core �bers can improve photocatalyticactivity.

Moreover, PAN and PVP polymers have an im-

Figure 11. (a) UV-Vis absorbance and (b)photocatalytic degradation rate of MO under UV-lightirradiation for of TiO2 NPs.

portant role in photocatalytic performance of core-shell nano�bers. There are some reports showingthat PVP and PAN polymers are good templates,which enhance photocatalytic e�ciency of tube-brush-like ZnO nanostructures, and BiOBr nanosheets andFe (III)-amidoximated, respectively [23,30,31].

PAN and PVP polymer matrixes were used tofabricate a 1D core-shell structure that promoted UV-shielding e�ciency and photocatalytic performance ofcore-shell structure. TiO2/SiO2 core-shell nano�bersindicate very good potential for better applications inUV light shielding devices and UV-sensitive materials.

4. Conclusions

In summary, TiO2/SiO2 core-shell nano�bers were suc-cessfully synthesized using single-nozzle co-electrospin-ning process and sol-gel approach.

TEM and SEM micrographs illustrate that theintended core-shell structures have formed success-fully. Structural properties of as-prepared sampleswere investigated by XRD, FTIR, and EDS techniques.FTIR spectra illustrate that absorption peaks at 550-800 cm�1 and about 1095 cm�1 are related to the


existence of Ti-O and Si-O bonds in the samples.Furthermore, EDS characterizations show the presenceof C, O, Ti, and Si elements in the core-shell structures.

PAN and PVP polymers were used as a new car-rier for TiO2 and SiO2 NPs and enhanced UV-shieldingactivity and photocatalytic performance of TiO2/SiO2core-shell nano�bers. All UV and DUV rays wereshielded by TiO2/SiO2 core-shell nano�bers with thehighest amount of TiO2 and SiO2 precursors. UV-Vistransmittances approached almost zero for sample c.This unique nanostructure exhibits excellent potentialfor photocatalytic and UV-shielding application; thus,it can be a good candidate for fabrication coatings withUV-prevention and photocatalytic properties.

References

1. Bayal, N. and Jeevanandam, P. \Synthesis of TiO2-MgO mixed metal oxide nanoparticles via a sol-gelmethod and studies on their optical properties", Ce-ram. Int., 40(10), pp. 15463-15477 (2014).

2. Zhang, Y., Zhuang, S., Xu, X. and Hu, J. \Transparentand UV-shielding ZnO@PMMA nanocomposite �lms",Opt. Mater. (Amst)., 36(2), pp. 169-172 (2013).

3. Luo, J., Ma, S.Y., Li, F.M., Li, X.B., Li, W.Q., Cheng,L., Mao, Y.Z. and GZ, D. \The mesoscopic structureof ower-like ZnO nanorods for acetone detection",Mater. Lett., 121, pp. 137-140 (2014).

4. Saini, P. and Choudhary, V. \Enhanced electromag-netic interference shielding e�ectiveness of polyani-line functionalized carbon nanotubes �lled polystyrenecomposites", J. Nanoparticle Res., 15(1), pp. 1415(2013).

5. Zhang, Y. and Li, P. \Porous Zr-doped SiO2

shell/TiO2 core nanoparticles with expanded channelsfor photocatalysis", Mater. Des., 88, pp. 1250-1259(2015).

6. Ukaji, E., Furusawa, T., Sato, M. and Suzuki, N.\The e�ect of surface modi�cation with silane couplingagent on suppressing the photo-catalytic activity of�ne TiO2 particles as inorganic UV �lter", Appl. Surf.Sci., 254(2), pp. 563-569 (2007).

7. Ramasamy, M., Kim, Y.J., Gao, H., Yi, D.K.and An, J.H. \Synthesis of silica coated zinc oxide-poly(ethylene-co-acrylic acid) matrix and its UVshielding evaluation", Mater. Res. Bull., 51, pp. 85-91 (2014).

8. Matsumura, Y. and Ananthaswamy, H.N. \Toxic ef-fects of ultraviolet radiation on the skin", Toxicol.Appl. Pharmacol., 195(3), pp. 298-308 (2004).

9. Guo, N., Liang, Y., Lan, S., Liu, L., Ji, G., Gan,S., Zou, H. and Xu, X. \Uniform TiO2-SiO2 hol-low nanospheres: Synthesis, characterization and en-hanced adsorption-photodegradation of azo dyes andphenol", Appl. Surf. Sci., 305, pp. 562-574 (2014).

10. Thi, T., Nguyen, T., Hee, O. and Seo, J. \Coaxialelectrospun poly ( lactic acid )/chitosan ( core/shell )composite nano�bers and their antibacterial activity",Carbohydr. Polym., 86(4), pp. 1799-1806 (2011).

11. Savva, I., Kalogirou, A.S., Chatzinicolaou, A., Papa-philippou, P., Pantelidou, A., Vasile, E., Koutentis,P.A. and Krasia-Christoforou, T. \PVP-crosslinkedelectrospun membranes with embedded Pd and Cu2Onanoparticles as e�ective heterogeneous catalytic sup-ports", RSC Adv., 4(85), pp. 44911-44921 (2014).

12. Wang, Y., Mo, Z., Zhang, C., Zhang, P., Guo, R., Gou,H., Hu, R. and Wei, X. \Morphology-controllable 3D ower-like TiO2 for UV shielding application", J. Ind.Eng. Chem., 32, pp. 172-177 (2015).

13. Xue, C.H., Yin, W., Zhang, P., Zhang, J., Ji, P.T. andJia, S.T. \UV-durable superhydrophobic textiles withUV-shielding properties by introduction of ZnO/SiO2

core/shell nanorods on PET �bers and hydrophobiza-tion", Colloids Surfaces A Physicochem. Eng. Asp.,427, pp. 7-12 (2013).

14. Nam, I.W., Kim, H.K. and Lee, H.K. \In uence ofsilica fume additions on electromagnetic interferenceshielding e�ectiveness of multi-walled carbon nan-otube/cement composites", Constr. Build. Mater., 30,pp. 480-487 (2012).

15. Sau�, S., and Ismail, A. \Development and characteri-zation of polyacrylonitrile (PAN) based carbon hollow�ber membrane", Songklanakarin J. Sci. Technol., 24,pp. 843-854 (2002).

16. Nakhaei, O., Shahtahmassebi, N. and Azhir, E. \Co-precipitation synthesis of CaF2:Er nanocompositesand photoluminescence characterizations of electro-spun polyvinyl alcohol/CaF2:Er nano�bers", Indian J.Phys., 88(12), pp. 1245-1250 (2014).

17. Lee, J.S., Kwon, O.S. and Jang, J. \Facile synthesis ofSnO2 nano�bers decorated with N-doped ZnO nanon-odules for visible light photocatalysts using single-nozzle co-electrospinning", J. Mater. Chem., 22(29),p. 14565 (2012).

18. Geng, Q. and Cui, W. \Adsorption and photocat-alytic degradation of reactive brilliant red K-2BP byTiO2/AC in bubbling uidized bed photocatalyticreactor", Ind. Eng. Chem. Res., 49(22), pp. 11321-11330 (2010).

19. Ukaji, E., Furusawa, T., Sato, M. and Suzuki, N.\The e�ect of surface modi�cation with silane couplingagent on suppressing the photo-catalytic activity of�ne TiO2 particles as inorganic UV �lter", Appl. Surf.Sci., 254(2), pp. 563-569 (2007).

20. Kayaci, F., Vempati, S., Ozgit-Akgun, C., Donmez, I.,Biyikli, N. and Uyar, T. \Transformation of polymer-ZnO core-shell nano�bers into ZnO hollow nano�bers:Intrinsic defect reorganization in ZnO and its in uenceon the photocatalysis", Appl. Catal. B Environ., 176,pp. 646-653 (2015).


21. Qiu, Y., Yin, J., Hou, H., Yu, J. and Zuo, X.\Preparation of nitrogen-doped carbon submicrotubesby coaxial electrospinning and their electrocatalyticactivity for oxygen reduction reaction in acid media",Electrochim. Acta, 96, pp. 225-229 (2013).

22. Farsani, R., Raissi, S., Shokuhfar, A. and Sedghi, A.\FT-IR study of stabilized PAN �bers for fabricationof carbon �bers", World Acad. Sci., Engineering andTechnology, 50, pp. 430-433 (2009).

23. Liu, C., Li, X., Ma, B., Qin, A. and He, C. \Removalof water contaminants by nanoscale zero-valent ironimmobilized in PAN-based oxidized membrane", Appl.Surf. Sci., 321, pp. 158-165 (2014).

24. Fateh, R., Dillert, R. and Bahnemann, D. \Self-cleaning properties, mechanical stability, and adhesionstrength of transparent photocatalytic TiO2-ZnO coat-ings on polycarbonate", ACS Appl. Mater. Interfaces,6(4), pp. 2270-2278 (2014).

25. Nakhaei, O., Shahtahmessebi, N. and Rezaee Rokn-abadi, M. \Synthesis and characterization of CaF2 NPswith co-precipitation and hydrothermal method", J.Nanomed. Nanotechnol., 2(5) (2011).

26. Farimani, M.H.R., Shahtahmasebi, N., Rezaee Rokn-abadi, M., Ghows, N. and Kazemi, A. \Study ofstructural and magnetic properties of superparamag-netic Fe3O4/SiO2 core-shell nanocomposites synthe-sized with hydrophilic citrate-modi�ed Fe3O4 seeds viaa sol-gel approach", Phys. E Low-dimensional Syst.Nanostructures, 53, pp. 207-216 (2013).

27. Fu, J., Wang, Y. and Zhu, Y. \Broadband andhigh di�use re ectivity of hollow mesoporous silicananospheres and their UV light shielding ability forlight-labile peroxides", Mater. Lett., 153, pp. 89-91(2015).

28. Khan, R., Shamshi Hassan, M., Uthirakumar, P.,Yun, J.H., Khil, M.S. and Lee, I.H. \Facile synthesisof ZnO nanoglobules and its photocatalytic activityin the degradation of methyl orange dye under UVirradiation", Mater. Lett., 152, pp. 163-165 (2015).

29. Liu, Z., Miao, Y.E., Liu, M., Ding, Q., Tjiu,W.W., Cui, X. and Liu, T. \Flexible polyaniline-coated TiO2/SiO2 nano�ber membranes with en-

hanced visible-light photocatalytic degradation per-formance", J. Colloid Interface Sci., 424, pp. 49-55(2014).

30. Chen, X., Zhai, Y., Li, J., Fang, X., Fang, F., Chu,X., Wei, Z. and Wang, X. \Increased photocatalyticactivity of tube-brush-like ZnO nanostructures fabri-cated by using PVP nano�bers as templates", Appl.Surf. Sci., 319, pp. 216-220 (2014).

31. Li, Y., Wang, Z., Huang, B., Dai, Y., Zhang, X.and Qin, X. \Synthesis of BiOBr-PVP hybrids withenhanced adsorption-photocatalytic properties", Appl.Surf. Sci., 347, pp. 258-264 (2015).

Biographies

Omolfajr Nakhaei received her BS and MS degreesfrom Ferdowsi University of Mashhad, where she is aPhD candidate of Solid State Physics. Her researchinterests focus on nanoscience, especially in synthe-sizing nanoparticles, nanocomposites, and nano�berswith unique properties.

Nasser Shahtahmassebi received his BS degree inPhysics from Ferdowsi University of Mashhad and PhDdegree in Theoretical Condensed Matter Physics fromImperial College London. He is Professor and Head ofNanoresearch Center at Ferdowsi University of Mash-had. His research interests focus on theoretical solid-state physics and nanoscience, especially synthesizingvarious kinds of nanomaterials with unique properties.

Mahmood Rezaee Roknabadi has PhD degreein Solid-State Physics. He is Professor at FerdowsiUniversity of Mashhad. His research interests focuson applied physics, theoretical projects in solid-statephysics, magnetic material, and nanoscience.

Mohamad Behdani received his PhD degree fromFerdowsi University of Mashhad, where he is a lecturer.His research interests focus on synthesis of magneticand superconductive materials and nanotechnology.

Fabrication and study of UV-shielding and photocatalytic...

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