SynthesisofAl-MCM-41@Ag/TiO NanocompositeandIts ...downloads.hindawi.com/journals/jchem/2018/8418605.pdf · ResearchArticle SynthesisofAl-MCM-41@Ag/TiO 2NanocompositeandIts PhotocatalyticActivityforDegradationofDibenzothiophene

Research ArticleSynthesis of Al-MCM-41AgTiO2 Nanocomposite and ItsPhotocatalytic Activity for Degradation of Dibenzothiophene

Xuan Nui Pham 1 Tuan Dat Pham1 Ba Manh Nguyen12 Hoa Thi Tran23

and Dinh Trong Pham4

1Department of Chemical Engineering Hanoi University of Mining and Geology 18 Duc ang Bac Tu Liem Hanoit Vietnam2Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Hanoi Vietnam3Department of Chemical Engineering Viet Tri University of Industry 9 Tien Son Str Viet Tri City Vietnam4Faculty of Chemistry Hanoi University of Science Vietnam National University 19 Le anh TongHoan Kiem Hanoi Vietnam

Correspondence should be addressed to Xuan Nui Pham phamxuannuigmailcom

Received 11 June 2018 Accepted 16 October 2018 Published 5 December 2018

Academic Editor Stefano Caporali

Copyright copy 2018 Xuan Nui Pham et al is is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Mesoporous Al-MCM-41AgTiO2 nanocomposites were synthesized successfully by combining the sol-gel method and hy-drothermal treatment using titanium isopropoxide (TTIP) AgNO3 and Vietnamese bentonite as precursors of Ti Ag and Sirespectively e synthesized materials were well characterized by X-ray powder diffraction (XRD) scanning electron microscopy(SEM) transmission electron microscopy (TEM) N2 adsorption-desorption isotherm measurements energy dispersive X-rayspectroscopy (EDX) UV-visible diffuse reflectance spectroscopy (UV-VisDRS) and X-ray photoelectron spectroscopy (XPS)e photocatalytic activity was evaluated by the photodegradation of dibenzothiophene (DBT) under both UV and visible lightirradiation MCM-41AgTiO2 catalyst exhibited high catalytic activity for the oxidative desulfurization (ODS) of DBT reachingalmost 100 conversions at 50degC after 2 h under UV and visible light irradiations e significant enhanced degradation of DBTover Al-MCM-41AgTiO2 might be due to the synergy effects of high surface area of MCM-41 well-distributed TiO2 anataseand reduced electron-hole recombination rates due to the dispersion of Ag nanoparticles

1 Introduction

Dibenzothiophene presenting in diesel is one of the mainsulfur-containing organic pollutants in fuel oils and is dif-ficult to be removed [1] is organic pollutant is difficult tobe reduced using the conventional hydrodesulfurization(HDS) due to its steric hindrance [2 3] Photocatalyticoxidation is one of the most promising pollution treatmentsto remove many organic pollutants in water [4] and airsteam [5] Due to more stringent environmental regulationsit is critical to develop effective photocatalysts for the re-moval of sulfur-containing organic compounds from fueloils through photocatalytic oxidation processes Titaniumdioxide (TiO2) has been well known and was the most widelystudied semiconductor photocatalyst due to its low costnontoxicity and high chemical stability [6] However the

semiconductor TiO2 has a wide band gap (30ndash32 eV) thatstrongly restricted its application because the material onlyabsorbs a small fraction of the solar photons (the UV lightoccupies about 5 of the total solar energy) Besides highrecombination between electrons (eminus) and holes (h+) resultsin reduced photocatalytic efficiency [7 8]

e incorporation and doping of noble metal nano-particles (eg Ag Au and Pt) into the crystal lattice of TiO2(metal-TiO2) to absorb the abundant visible light due to theirsurface plasmon resonance (SPR) have been investigated toovercome this limitation in the TiO2 photocatalyst material[9ndash12] Silver has an advantage of having a lower costcompared with gold or platinum However the use of metal-TiO2 powders in the treatment of aqueous organic pollutantshas some drawbacks such as difficult recovery and poor ad-sorption capacity due to its low surface area and agglomeration

HindawiJournal of ChemistryVolume 2018 Article ID 8418605 9 pageshttpsdoiorg10115520188418605

in suspension [13] erefore noble metal nanoparticlesdoping on titania with improved crystallinity surface area andsurface properties to achieve higher adsorption capacity andphotocatalytic activity [14] have been studied extensively suchas metal-titania nanoparticles coated on the high surface areasupports and thermally stable core materials [15 16] Nano-porous materials such as ordered mesoporous silica [17ndash19]activated carbon [20 21] microporous zeolites [22 23] andmetal organic frameworks [24 25] have been widely used asTiO2 carriers due to their versatile structures and high porosityto achieve more active sites per unit area consequentlya higher photocatalytic reaction rate Mesoporous alumino-silicate Al-MCM-41 is one of the most widely used supportmaterials due to its remarkable acidic properties high thermaland mechanical stability highly ordered hexagonal structureand high surface area [26ndash30] Recent studies have focused onthe use of low-cost raw materials particularly in their naturalforms such as bentonite clay to synthesize high value productse inorganic components consisting of silica and aluminawere collected by annealing bentonite with sodium hydroxideat a temperature higher than 500degC to use for the synthesis ofAl-MCM-41 [31 32] Herein the Al-MCM-41 mesoporousmaterial was prepared by a hydrothermal method using theVietnamese bentonite as Si and Al precursors en AgTiO2nanoparticles were deposited on the surface of the Al-MCM-41material to improve the dispersion of TiO2 and the synthesizedAl-MCM-41AgTiO2 nanocomposites were used as a pho-tocatalyst for the oxidative desulfurization of dibenzothio-phene under both UV and visible light irradiation

2 Experimental

21 Chemicals Dibenzothiophene (DBT) triblock PluronicF127 (EO106PO70EO106 99 wtM 12600) titanium (IV)isopropoxide (TTIP 97 wt) n-octane (99 wt) silvernitrate (99 wt) cetyltrimethylammonium bromide(CTAB 98 wt) ethanol (995 wt) acetic acid (99 wt)hydrogen peroxide (30wt) and NaOH (98wt) werepurchased from either Sigma-Aldrich or Merck Bentonitewas obtained from Di Linh Vietnam with a chemicalcomposition of 52 SiO2 15 Al2O3 11 Fe2O3 08 TiO2 2CaO 35 MgO 2 Na2O in weight percent and the loss onignition (LOI) of 137

22 Synthesis of Al-MCM-41 from Vietnamese BentoniteFirstly Si and Al precursors were obtained following theprotocol described by Ali-dahmane et al [31] e Viet-namese bentonite was mixed with sodium hydroxide(NaOH) in bentonite NaOH weight ratio of 1 12 andheated at 550degC for 3h in air e fused bentonite obtainedwas cooled milled mixed with distilled water with a weightratio of 1 4 and then stirred at room temperature for 24 he supernatant was separated by centrifugation to obtainthe Si and Al precursors

In a typical Al-MCM-41 synthesis 12 g CTAB wasadded to 20mL distilled water en 42mL of the super-natant was added to the above solution and stirred at roomtemperature for 6 h at pH of about 9-10 which was adjusted

by acetic acid e crystallization step was carried out at100degC in a stainless steel autoclave for 24 hours e whiteprecipitate was then filtered and washed three times withdistilled water and ethanol and dried overnight at 100degCFinally the template CTAB was removed by calcining at550degC for 6 h in air

23 Synthesis of Al-MCM-41nAgTiO2 NanocompositeAl-MCM-41nAgTiO2 nanocomposite microspheres weresynthesized by a sol-gel method 01 g of the synthesized Al-MCM-41 was dispersed in 100mL ethanol via sonication for1 h en 02 g F127 and 2mL distilled water were added tothe above solution e mixture was stirred at 50degC for 30minutes

A TiO2 precursor (solution A) was prepared by dis-solving titanium(IV) isopropoxide (TTIP) in a mixed sol-vent of ethanol and nitric acid to form a final composition of1 TTIP C2H5OH 2 H2O 02 HNO3 Solution B was pre-pared by adding n (n 5 10 and 15) moles of AgNO3into 15mL ethanol and stirred for 30 minutes en so-lution A was mixed with solution B and stirred vigorouslyfor 30 minutes e AgTiO2 precursor was added dropwiseto the Al-MCM-41 suspension to obtain Al-MCM-41nAgTiO2 e temperature was then increased to 80degCunder refluxing conditions for 6 he solid was collected bycentrifugation and washed thoroughly with ethanol anddried at 80degC Finally F127 was removed by calcining theobtained solid at 450degC in air for 5 h

24 Oxidative Photodesulfurization of DibenzothiopheneDibenzothiophene was dissolved in n-octane to createa model fuel with known sulfur content in ppm Next 20mLof DBTn-octane solution was placed in a 500ml three-neckround-bottom flask containing 005 g catalyst e suspen-sion was stirred for 30 minutes in the dark and then wasilluminated with two 15W UV lamps (UV light) or a 165Wtungsten lamp (visible light) at various temperatures (30degC50degC and 70degC) under refluxing conditions for 5 h 05mL ofH2O2 as an oxidative agent was added to the mixture at thereaction temperatures After certain reaction time smallamounts of the products were taken out centrifuged andanalyzed by high-performance liquid chromatography(HPLC) en peak areas were converted to their corre-sponding concentrations through the standard curves epercentage of degradation of DBT (η) was calculatedaccording to the initial C0 (ppm) and final C (ppm)concentrations of DBT in the solution following thisequation η 100 times (C0 ndashC)C0

25 Characterization Powder X-ray diffraction (XRD)patterns were recorded on a D8-Advance Bruker with Cu-Kα radiation (λ 015406 nm) as the X-ray source at a scanrate of 03degndash06degminminus1 Transmission electron microscopy(TEM) images were taken by a TEM TECNAI G 2 20 with anaccelerating voltage of 200 kV Scanning electron microscopy(SEM) images were obtained on an S4800-Hitachi Pore sizedistributions were calculated from N2 isotherms using the

2 Journal of Chemistry

BarrettndashJoynerndashHalenda (BJH) model Energy dispersiveX-ray (EDX) spectra were measured on a JED-2300 in-strumente surface electronic states identified throughX-rayphotoelectron spectroscopy (XPS) were taken on an AXISULTRA DLD ShimadzundashKratos spectrometer using mono-chromatic X-rays Al-Kα radiation (14866 eV) UV-Vis diffusereflection spectroscopy (UV-VisDRS) was performed ona Shimadzu UV2550 spectrophotometer with a BaSO4-coatedintegrating sphere in the wavelength range of 200ndash800nm

3 Results and Discussion

31 Characterizations of the Synthesized MaterialsWide-angle XRD patterns of Al-MCM-41 Al-MCM-41TiO2 and Al-MCM-41AgTiO2 with different Ag con-centrations are shown in Figure 1 e XRD pattern of Al-MCM-41 (Figure 1(e)) does not have diffraction peaks in therange of 15o to 30o indicating a characteristic of amor-phous silica walls of the pristine material In contrast Al-MCM-41TiO2 (Figure 1(d)) and Al-MCM-41AgTiO2(Figures 1(a)ndash1(c)) contain diffraction peaks at 2θ 254deg379deg 484deg 540deg 552deg and 628deg corresponding to (101)(004) (200) (105) (211) and (204) planes of a typical TiO2anatase phase respectively [33] Al-MCM-41AgTiO2composites contain obvious diffraction peaks of TiO2 but notypical peaks of Ag were observed is might be due to thelow concentration of Ag or the typical diffraction peaks of Agwere covered by a (004) diffraction peak of the TiO2 anatasee presence of Ag in the Al-MCM-41AgTiO2 compositeswill be discussed later using EDX and XPS methods

Figure 1 (inset) is the small angle XRD results of Al-MCM-41 Al-MCM-41TiO2 and Al-MCM-41AgTiO2Diffraction peaks at 2θ 23deg 39deg and 45deg of the Al-MCM-41 sample were assigned respectively to (100) (110) and(200) planes associated with a p6mm hexagonal symmetryof a mesoporous material with highly uniform and orderedstructure However the peak intensities at 2θ 23degwere significantly reduced and the other peaks at 39deg and45deg were not clear (Figures 1(a)ndash1(d) (inset)) is couldbe due to the existence of TiO2 and AgTiO2 inside thechannels of Al-MCM-41TiO2 and Al-MCM-41AgTiO2 materials

SEM images of Al-MCM-41 and Al-MCM-4101AgTiO2 are shown in Figure 2 e SEM images of Al-MCM-41 revealed irregular spherical particles with a cross-linked network and a particle size of about 120 nm eaverage particle size of Al-MCM-410 1AgTiO2 (150 nm)was larger than that of Al-MCM-41 nanoparticleswhich indicated a possible coverage of TiO2 nanoparticleshaving a thickness of about 15 nm on the surface of theAl-MCM-410 1AgTiO2 nanocomposite

Figures 3(a) and 3(b) are the TEM images ofAl-MCM-410 1AgTiO2 catalyst e TEM images showedthat the nanocomposite possesses ordered mesoporouschannels with a slight decrease in the orderly porousstructure as compared to the parent Al-MCM-41 materialwhich is in agreement with the XRD result e AgTiO2particles having the size of about 5ndash15 nm were well-

dispersed on the surface and mesopore of the Al-MCM-41 support

e UV-Vis diffuse reflectance spectra of Al-MCM-41Al-MCM-41TiO2 and Al-MCM-41nAgTiO2 compositesin the range of 250ndash800 nm are shown in Figure 4 e strongUV absorption spectrum of Al-MCM-41TiO2 observed atstrong absorption band at wavelengths from 250 to 380 nmwith the sharp absorption edge of about 330 nm is attributedto the intrinsic band gap absorption of anatase TiO2 [34] Al-MCM-410 1AgTiO2 and Al-MCM-410 15AgTiO2 con-taining a high amount of Ag nanoparticles showed a lightabsorption band in the visible region with peaks at about435 nmis could be related to the localized surface plasmonresonance effect of silver nanoparticles [35] which varies withthe Ag content of MCM-41AgTiO2 nanostructures eband gaps of the composite samples were calculated fromtheir UV-VisDRS spectra based on the method proposed byKumar et al [36] using the following equation

αh] Ah]minusEg1113872 1113873n2

(1)

where Eg is the band gap (eV) ] is the light frequency A is theabsorption constant h is Planckrsquos constant and α is the ab-sorption coefficient e band gap Eg values of Al-MCM-41TiO2 Al-MCM-410 05AgTiO2 Al-MCM-4101AgTiO2and Al-MCM-41015AgTiO2 were 320 29 283 and281 eV respectivelyese results indicated that the dispersionof silver nanoparticles on TiO2 increases the absorption of lightin the visible region and narrows their band gaps In additionthe Ag nanoparticles acted as electron traps to inhibit re-combination [37] which may be beneficial for improving thecatalytic activity of the catalysts

10 20 30 40 50 60 70

(204)(211)(200)(004)

(e)

(d)

(b)

(c)

Inte

nsity

(au

)2 Theta (degree)

(a)

(101)1 2 3 4 5 6 7 8 9 10

(200)(110)

(a)

(b)(c)

(d)

2 Theta (degree)

(e)

(100)

Inte

nsity

(au

)

Figure 1 XRD patterns of (a) Al-MCM-410 15AgTiO2 (b) Al-MCM-410 1AgTiO2 (c) Al-MCM-410 05AgTiO2 (d) Al-MCM-41TiO2 and (e) Al-MCM-41 Inset is the small angle X-raydiffraction patterns

Journal of Chemistry 3

e EDX of Al-MCM-410 1AgTiO2 (Figure 5) con-firmed the presence of the elements of O Si Al Ti and Agwith no other impurities observed e weight percentage ofAg loaded into TiO2 was 601 (corresponding to AgTi 0095) which is very close to the calculated value of AgTi 01 e EDX analysis of the Al-MCM-410 1AgTiO2sample revealed a SiAl ratio of about 12 is value con-firmed that a fairly high amount of aluminum obtained fromthe Vietnamese bentonite was incorporated into thestructure of silica MCM-41

e N2 adsorption-desorption isotherms of Al-MCM-41and Al-MCM-410 1AgTiO2 were typical for type IV witha hysteresis loop characteristic of mesoporous materials(Figure 6) e calculated specific surface area (SBET) of Al-MCM-41 was 633m2middotgminus1 with a pore volume of 09 cm3middotgminus1and of Al-MCM-410 1AgTiO2 was 144m2middotgminus1 with a porevolume of 03 cm3middotgminus1 e specific surface area and mes-oporous volume of Al-MCM-41 loading AgTiO2 were lowerthan those of the pristine Al-MCM-41 which is due to theblocking of some pores by the doping of AgTiO2nanoparticles

XPS analysis was carried out to analyze the surfacecomposition and chemical states of Al-MCM-4101AgTiO2 (Figure 7(a)) e spectrum confirmed thepresence of O Si Al Ti and Ag elements without any otherimpurities Figure 7(b) is the high-resolution XPS spectrum

(a) (b)

Figure 2 SEM images of (a) Al-MCM-41 and (b) Al-MCM-410 1AgTiO2

(a) (b)

Figure 3 TEM images of Al-MCM-410 1AgTiO2

300 400 500 600 700 800

Abs

orba

nce (

au)

Wavelength (nm)

Al-MCM-41TiO2Al-MCM-410 05AgTiO2Al-MCM-410 15AgTiO2Al-MCM-410 1AgTiO2Al-MCM-41

Figure 4 UV-Vis diffuse reflectance spectra of Al-MCM-41015AgTiO2 Al-MCM-410 1AgTiO2 Al-MCM-410 05AgTiO2 Al-MCM-41TiO2 and Al-MCM-41


middotmiddot

middot

middot

of Ag 3d of Al-MCM-410 1AgTiO2 Two observed energybands at 36751 eV and 37351 eV correspond to Ag 3d52 andAg 3d32 of metallic silver ese bands are slightly lowerthan the bulk Ag metal at 368 eV and 374 eV indicatinga strong interaction between Ag and TiO2 e splittingenergy between Ag 3d52 and Ag 3d32 is 6 eV which furtherconfirmed the existence of metallic Ag nanoparticles in thesynthesized Al-MCM-410 1AgTiO2 material [35 38] It isalso clearly observed that the presence of two different peaksfor Ag 3d52 binding energies at 3681 eV and 3676 eVwere assigned to metallic silver (Ag0) and silver ions in Ag2O(Ag+) respectively [39] us partially oxidized metallic Agnanoparticles were deposited on the TiO2 surface during the

synthesis Figure 7(c) is the high-resolution XPS spectrum ofTi 2p of Al-MCM-410 1AgTiO2 Ti 2p consists of twopeaks at 45848 eV and 46418 eV (splitting energy 57 eV)which are in accordance with Ti 2p32 and Ti 2p12 of Ti4+ inAgTiO2 nanostructures respectively [35 40]

32 Photocatalytic Activity of Nanocomposite e photo-catalytic performance of Al-MCM-41AgTiO2 with differentAg loadings was evaluated by the oxidative desulfurization ofDBT in the model fuel under the visible light source in 30minutes at 70degCe photocatalyst with lowAg loading (05wt AgTiO2) exhibited a weak performance (conversion ofDBTsim48) due to the low concentration of active catalyticsites whereas the highest efficiency was obtained for Al-MCM-410 1AgTiO2 (78 DBT conversion) Due to moresilver decorated on the surface of TiO2 for Al-MCM-41015AgTiO2 compared with Al-MCM-410 1AgTiO2 al-though they have almost the same band gaps the overlappingof the plasmonic field regionmakes the photocatalytic activityof Al-MCM-410 15AgTiO2 mesoporous structure decline(conversion of DBT is 65) However overloading of Ag willreduce the amount of available active sites due to the spatialcharge repulsion thereby affecting the photoactivity HenceAl-MCM-410 1AgTiO2 as a photocatalyst has the bestphotocatalytic activity due to its suitable plasma resonanceband narrow band gap and available active sites which is alsoconsistent with the literature [41ndash43] Al-MCM-4101AgTiO2 photocatalyst was then chosen to carry out thenext catalytic tests

For comparison the degradation of DBTover Al-MCM-41TiO2 by the irradiation of UV and visible light wascarried out At 70degC and after 2 hours the Al-MCM-41TiO2 photocatalyst degraded only about 40 of DBTunder UV light (Figure 8) and almost negligible degradationwas observed under visible light (not shown) Comparedwith Al-MCM-41TiO2 sample Al-MCM-410 1AgTiO2exhibited remarkably enhanced photocatalytic activitiesunder the same visible light and UV irradiation e pho-todegradation efficiencies of DBT increased to almost 100after 2 h at 70degC (Figure 8) e improved photocatalyticactivity of nanocomposite is due to the strong UV and visiblelight absorption of Al-MCM-410 1AgTiO2 material eAl-MCM-41 support with a large surface area will increasethe ability to disperse the catalytic activity center which willincrease the catalytic activity e surface plasmon reso-nance of silver nanoparticles was in the visible light regionleading to efficiently absorbing visible light irradiation Inaddition the excellent conductivity of silver nanoparticlesmay improve electron mobility to enhance the transfer ofsurface charge to the boundary and prevent the re-combination of electrons and holes Al-MCM-41 acted as anadsorbent in the reaction By using the sol-gel method theTiO2 silver-modified silver nanoparticles were homoge-neously distributed in ethanol thereby well dispersed on thepristine material through an intermediate polymer layer ofF-127 F-127 played a very important role in TiO2-coateddenaturing with Ag because without F-127 TiO2 nano-particles are difficult to bond with Al-MCM-41 formed On

0 1 2 3 4 5 6 7 8 9 10

Ti

Ti

Ti

Si

Al Ag

O

Full scale 339 cts cursor 13136keV (0 cts)

Figure 5 EDX spectrum of Al-MCM-410 1AgTiO2

00 02 04 06 08 100

100

200

300

400

500

600

(b)Ads

orpt

ion

volu

me (

cm3 g

)

Relative pressure (PP0)

(a)

Figure 6 N2 adsorption-desorption isotherms of (a) Al-MCM-41and (b) Al-MCM-410 1AgTiO2


16

14

12

10

8

6

4

2

01200

Inte

nsity

(au

)

900 600 300 0Binding energy (eV)

times104

Ti2a

Ti2p

Ag3d

O1s C1s

Ti3a

Ti3pSi2p Si2a

(a)

210

200

190

180

170

Inte

nsity

(au

)

160

150

140

130

120

Binding energy (eV)

Ag3d

384 380 376 372 368 364 360

times101

(b)

40

times102

35

30

25

20

15

476 472 468 464 460 456 452 448

Ti2p

Inte

nsity

(au

)

Binding energy (eV)

(c)

Figure 7 XPS spectra of (a) Al-MCM-410 1AgTiO2 (b) Ag3d and (c) Ti2p

0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersin

of D

BT (

)

Reaction time (h)

Visible_Al-MCM-410 1AgTiO2UV_Al-MCM-41TiO2UV_Al-MCM-410 1AgTiO2

Figure 8 Conversion of DBT over Al-MCM-41TiO2 and Al-MCM-410 1AgTiO2 under UVvisible light irradiation Experimentalconditions V (model fuel) 20mL mAlminusMCMminus410 1AgTiO2

005 g VH2O2 05mL and T 70degC


the other hand Al-MCM-41 covered with F-127 to helpdisperse the TiO2 nanoparticles onto the surface e F-127also protected the hexagonal structure of Al-MCM-41 in thecore without being broken down during synthesis Teng et al[44] showed that SiO2 not only played a role in the dis-persion of TiO2 but also protected the Fe3O4 core andprevented the core from dissolving into the solution in theformation of the sandwich structure of Fe3O4SiO2TiO2

e effect of temperature on the oxidative desulfurizationof DBT during UV and visible irradiations are shown inFigures 9 and 10 It can be seen that as the temperatureincreased from 30degC to 70degC under both UV and visible lightthe conversion of DBT increased and reached 100 at 70degCafter 2 hourse results are in good agreement with literaturethat increase in the reaction temperature improves thephotodegradation efficiency [45]

After 2 h at the reaction temperature slightly above roomtemperature (30degC) the deep desulfurization could beachieved with 89 and 81 conversions under UV and visiblelight irradiation respectively is was attributed to theformation of conduction band (CB) electrons (eminus) and valenceband (VB) holes (h+) under irradiationis indicates that thevisible light absorption of TiO2 samples was considerablyimproved by adding Ag and Al-MCM-41 to TiO2

Al-MCM-41 has a uniform pore structure and highsurface area which facilitates the high adsorption of DBTeAg nanoparticles were photoexcited to enable the generationof electron andAg+ (h+) due to the surface plasmon resonanceeffect and the photoexcited electrons can be further in-troduced into the conduction band of TiO2 (Equation (2))[34]e next possible reaction steps could happen as follows

Ag + visible light⟶ e + Ag+ h+( 1113857 (2)

TiO2 + h]⟶ h+VB + eCB (3)

TiO2(e) + O2⟶ Obullminus2 (4)

H2O2 + e⟶ bullOH +HOminus (5)

Ag+ h+

( 1113857bullOH Obullminus

2 e + DBT⟶ degradation products(6)

Species bullOH and O2bullminus obtained in the presence of the

photocatalyst and H2O2 as the oxidant under irradiationcould effectively oxidize DBT to its corresponding sulfone[46] Ag+ (h+) ions were reactive radical species which wereable to oxidize DBT and reduce to metallic silver us Agcould be rapidly regenerated and the Al-MCM-4101AgTiO2 composites remained stable

4 Conclusions

In summary the Al-MCM-41AgTiO2 nanocompositeshave been successfully synthesized using the Vietnamesebentonite as Si and Al sources and well characterized byvarious analytical techniques Al-MCM-41AgTiO2 com-posites exhibited much higher photocatalytic activities for

degrading DBT under visible light irradiation than Al-MCM-41TiO2 and Al-MCM-410 1AgTiO2 was foundto have the best photocatalytic performance IncorporatingAg and TiO2 into Al-MCM-41 substrate had positive effectson the photocatalytic activity of the TiO2 under both visiblelight and UV irradiations At a relatively mild condition of30degC DBT degraded 90 under UV light irradiation and81 under visible light after 2h At higher temperature(70degC) the DBT photooxidative desulfurization efficiencyof 100 could be achieved after 2 hours under visiblelight e Ag nanoparticle dispersed on Al-MCM-41TiO2

0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()

Reaction time (Hour)

30degC50degC70degC

Figure 9 Conversion of DBT under UV at various reactiontemperatures Experimental conditions V (model fuel) 20mLmAlminusMCMminus410 1AgTiO2

005 g and VH2O2 05mL

0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC

Figure 10 Conversion of DBTunder visible irradiation at variousreaction temperatures Experimental conditions V (model fuel) 20mL mAlminusMCMminus410 1AgTiO2



nanocomposites has shown its superiority and the potentialas a promising material for the removal of toxic organicpollutants either in the UV or visible light region

Data Availability

e data used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

e authors declare that they have no conflicts of interest

Acknowledgments

is work was funded by the Vietnam National Foundationfor Science and Technology Development (NAFOSTED)(grant number 10599-201521)

Supplementary Materials

e results of the HPLC analysis of the conversion of DBTwere investigated over time at various reaction temperaturesunder UV and visible irradiation conditions using Al-MCM410 1AgTiO2 and Al-MCM-41TiO2 catalysts(Supplementary Materials)

References

[1] T V Choudhary S Parrott and B Johnson ldquoUnravelingheavy oil desulfurization chemistry targeting clean fuelsrdquoEnvironmental Science and Technology vol 42 no 6pp 1944ndash19647 2008

[2] C Song ldquoAn overview of new approaches to deep de-sulfurization for ultra-clean gasoline diesel fuel and jet fuelrdquoCatalysis Today vol 86 no 1ndash4 pp 211ndash263 2003

[3] S Otsuki T Nonaka N TakashimaW Qian A Ishihara andT Imai ldquoOxidative desulfurization of light gas oil and vacuumgas oil by oxidation and solvent extractionrdquo Energy and Fuelsvol 14 no 6 pp 1232ndash1239 2000

[4] S Y Lee and S J Park ldquoTiO2 photocatalyst for watertreatment applicationsrdquo Journal of Industrial and EngineeringChemistry vol 19 no 6 pp 1761ndash1769 2013

[5] M A Kebede M E Varner N K Scharko R B Gerber andJ D Raff ldquoPhotooxidation of ammonia on TiO2 as a source ofNO and NO2 under atmospheric conditionsrdquo Journal of theAmerican Chemical Society vol 135 no 23 pp 8606ndash86152013

[6] M A Henderson ldquoA surface science perspective on TiO2photocatalysisrdquo Surface Science Report vol 66 no 6ndash7pp 185ndash297 2011

[7] S Ardo and G J Meyer ldquoPhotodriven heterogeneous chargetransfer with transition-metal compounds anchored to TiO2semiconductor surfacesrdquo Chemical Society Reviews vol 38no 1 pp 115ndash164 2009

[8] A A Ismail and D W Bahnemann ldquoMesoporous titaniaphotocatalysts preparation characterization and reactionmechanismsrdquo Journal of Material Chemistry vol 21 no 32pp 11686ndash11707 2011

[9] J Jiang H Li and L Zhang ldquoNew insight into daylightphotocatalysis of AgBrAg synergistic effect betweensemiconductor photocatalysis and plasmonic photocatalysisrdquo

ChemistryndashA European Journal vol 18 no 20 pp 6360ndash63692012

[10] F B Li and X Z Li ldquoe enhancement of photodegradationefficiency using PtndashTiO2 catalystrdquo Chemosphere vol 48no 10 pp 1103ndash1111 2002

[11] Y Borensztein L Delannoy A Djedidi R G Barrera andC Louis ldquoMonitoring of the plasmon resonance of goldnanoparticles in AuTiO2 catalyst under oxidative and re-ducing atmospheresrdquo Journal of Physical Chemistry Cvol 114 no 19 pp 9008ndash9021 2010

[12] Y Yu W Wen X Y Qian J B Liu and J M Wu ldquoUV andvisible light photocatalytic activity of AuTiO2 nanoforestswith anataserutile phase junctions and controlled Au loca-tionsrdquo Scientific Reports vol 7 article 41253 2017

[13] N Mandzy E Grulke and T Druffel ldquoBreakage of TiO2agglomerates in electrostatically stabilized aqueous disper-sionsrdquo Powder Technology vol 160 no 2 pp 121ndash126 2005

[14] Q Zhang J B Joo Z Lu et al ldquoSelf-assembly and photo-catalysis of mesoporous TiO2 nanocrystal clustersrdquo NanoResearch vol 4 no 1 pp 103ndash114 2011

[15] S Son S H Hwang C Kim J Y Yun and J Jang ldquoDesignedsynthesis of SiO2TiO2 coreshell structure as light scatteringmaterial for highly efficient dye-sensitized solar cellsrdquo ACS Ap-plied Materials and Interfaces vol 5 no 11 pp 4815ndash4820 2013

[16] A Hanprasopwattana T Rieker A G Sault and A K DatyeldquoMorphology of titania coatings on silica gelrdquo CatalysisLetters vol 45 no 3ndash4 pp 165ndash175 1997

[17] H Lachheb O Ahmed A Houas and J P Nogier ldquoPho-tocatalytic activity of TiO2ndashSBA-15 under UV and visiblelightrdquo Journal of Photochemistry and Photobiology AChemistry vol 226 no 1 pp 1ndash8 2011

[18] W T Qiao G W Zhou X T Zhang and T D Li ldquoPrep-aration and photocatalytic activity of highly ordered meso-porous TiO2ndashSBA-15rdquo Material Science and Engineering Cvol 29 no 4 pp 1498ndash1502 2009

[19] W J J Stevens K Lebeau M Mertens T G Van P Cooland E F Vansant ldquoInvestigation of the morphology of themesoporous SBA-16 and SBA-15rdquo Journal of PhysicalChemistry B vol 110 no 18 pp 9183ndash9187 2006

[20] M Asilturk and S Sener ldquoTiO2-activated carbon photo-catalysts preparation characterization and photocatalyticactivitiesrdquo Chemical Engineering Journal vol 180 pp 354ndash363 2012

[21] A C Martins A L Cazetta O Pezoti J R B SouzaT Zhang and E J Pilau ldquoSol-gel synthesis of new TiO2activated carbon photocatalyst and its application for deg-radation of tetracyclinerdquo Ceramics International vol 43no 5 pp 4411ndash4418 2017

[22] E Amereh and S Afshar ldquoPhotodegradation of acetophenoneand toluene in water by nano-TiO2 powder supported on NaXzeoliterdquo Material Chemitry and Physics vol 120 no 2ndash3pp 356ndash360 2010

[23] T Kamegawa Y Ishiguro R Kido and H YamashitaldquoDesign of composite photocatalyst of TiO2 and Y-zeolite fordegradation of 2-propanol in the gas phase under UV andvisible light irradiationrdquo Molecules vol 19 no 10pp 16477ndash16488 2014

[24] S Abedi and A Morsali ldquoOrdered mesoporous metalndashorganic frameworks incorporated with amorphous TiO2 asphotocatalyst for selective aerobic oxidation in sunlightirradiationrdquo ACS Catalysis vol 4 no 5 pp 1398ndash14032014

[25] A Crake K C Christoforidis A Kafizas S Zafeiratos andC Petit ldquoCO2 capture and photocatalytic reduction using


bifunctional TiO2MOF nanocomposites under UVndashvis ir-radiationrdquo Applied Catalysis B Environmental vol 210pp 131ndash140 2017

[26] S M V Phanikrishna K V Durga and M SubrahmanyamldquoPhotocatalytic degradation of isoproturon herbicide overTiO2Al-MCM-41 composite systems using solar lightrdquoChemosphere vol 72 no 4 pp 644ndash651 2008

[27] K C Park D J Yim and S K Ihm ldquoCharacteristics of Al-MCM-41 supported Pt catalysts effect of Al distribution inAl-MCM-41 on its catalytic activity in naphthalene hydro-genationrdquo Catalysis Today vol 74 no 3ndash4 pp 281ndash290 2002

[28] Z Diao L Wang X Zhang and G Liu ldquoCatalytic cracking ofsupercritical n-dodecane over meso-HZSM-5Al-MCM-41zeolitesrdquo Chemical Engineering Science vol 135 pp 452ndash4602015

[29] S Rodrigues S Uma I N Martyanov and K J KlabundeldquoAgBrAl-MCM-41 visible-light photocatalyst for gas-phasedecomposition of CH3CHOrdquo Journal of Catalysis vol 233no 2 pp 405ndash410 2005

[30] Y Ling M Long P Hu Y Chen and J Huang ldquoMagneticallyseparable corendashshell structural γ-Fe2O3CuAl-MCM-41nanocomposite and its performance in heterogeneous Fen-ton catalysisrdquo Journal of Hazardous Materials vol 264pp 195ndash202 2014

[31] T Ali-dahmane M Adjdir R Hamacha F VillierasA Bengueddach and P G Weidler ldquoe synthesis of MCM-41 nanomaterial from Algerian Bentonite the effect of themineral phase contents of clay on the structure properties ofMCM-41rdquo Comptes Rendus Chimie vol 17 no 1 pp 1ndash62014

[32] H Yang Y Deng C Du and S Jin ldquoNovel synthesis ofordered mesoporous materials Al-MCM-41 from bentoniterdquoApplied Clay Science vol 47 no 3ndash4 pp 351ndash355 2010

[33] L Liang Y Meng L Shi J Ma and J Sun ldquoEnhancedphotocatalytic performance of novel visible light-drivenAgndashTiO2SBA-15 photocatalystrdquo Superlattices and Micro-structures vol 73 pp 60ndash70 2014

[34] Q Xiang J Yu B Cheng and H C Ong ldquoMicrowave-hydrothermal preparation and visible-light photoactivity ofplasmonic photocatalyst Ag-TiO2 nanocomposite hollowspheresrdquo ChemistryndashAn Asian Journal vol 5 pp 1466ndash14742010

[35] Y Zhang T Wang M Zhou Y Wang and Z ZhangldquoHydrothermal preparation of Ag-TiO2 nanostructures withexposed 001101 facets for enhancing visible light pho-tocatalytic activityrdquo Ceramics International vol 43 no 3pp 3118ndash3126 2017

[36] V Kumar S Kr Sharma T P Sharma and V Singh ldquoBandgap determination in thick films from reflectance measure-mentsrdquo Optical Materials vol 12 no 1 pp 115ndash119 1999

[37] S Krejcıkova L Matejova K Kocı L Obalova Z Matej andL Capek ldquoPreparation and characterization of Ag-dopedcrystalline titania for photocatalysis applicationsrdquo AppliedCatalysis B Environmental vol 111-112 pp 119ndash125 2012

[38] L Zhang D Shi B Liu G Zhang Q Wang and J A ZhangldquoA facile hydrothermal etching process to in situ synthesizehighly efficient TiO2Ag nanocube photocatalysts with high-energy facets exposed for enhanced photocatalytic perfor-mancerdquo CrystEngComm vol 18 no 34 pp 6444ndash6452 2016

[39] P Prieto V Nistor K Nouneh M Oyama M Abd-Lefdiland R Dıaz ldquoXPS study of silver nickel and bimetallicsilverndashnickel nanoparticles prepared by seed-mediatedgrowthrdquo Applied Surface Science vol 258 no 22 pp 8807ndash8813 2012

[40] L Xu E M P Steinmiller and S E Skrabalak ldquoAchievingsynergy with a potential photocatalytic Z-scheme synthesisand evaluation of nitrogen-doped TiO2SnO2 compositesrdquoJournal of Physical Chemistry C vol 116 no 1 pp 871ndash8772012

[41] K H Leong B L Gan S Ibrahim and P SaravananldquoSynthesis of surface plasmon resonance (SPR) triggered AgTiO2 photocatalyst for degradation of endocrine disturbingcompoundsrdquo Applied Surface Science vol 319 pp 128ndash1352014

[42] W Zhao L Feng R Yang J Zheng and X Li ldquoSynthesischaracterization and photocatalytic properties of Ag modi-fied hollow SiO2TiO2 hybrid microspheresrdquo Applied Catal-ysis B Environmental vol 103 no 1-2 pp 181ndash189 2011

[43] D Lu S Ouyang H Xu D Li X Zhang and Y Li ldquoDe-signing Au surface-modified nanoporous-single-crystallineSrTiO3 to optimize diffusion of surface plasmon resonance-induce photoelectron toward enhanced visible-light photo-activityrdquo ACS Applied Material and Interfaces vol 8 no 14pp 9506ndash9513 2016

[44] Z Teng X Su G Chen C Tian H Li and L Ai ldquoSuper-paramagnetic high-magnetization composite microsphereswith Fe3O4SiO2 core and highly crystallized mesoporousTiO2 shellrdquo Colloid and Surface A Physicochemical Engi-neering Aspects vol 402 pp 60ndash65 2012

[45] N A M Barakat M A Kanjwal I S Chronakis andH Y Kim ldquoInfluence of temperature on the photo-degradation process using Ag-doped TiO2 nanostructuresnegative impact with the nanofibersrdquo Journal of MolecularCatalysis A Chemical vol 366 pp 333ndash340 2013

[46] H Lu J Gao Z Jiang Y Yang B Song and C Li ldquoOxidativedesulfurization of dibenzothiophene with molecular oxygenusing emulsion catalysisrdquo Chemical Communication vol 2pp 150ndash152 2007


Hindawiwwwhindawicom

International Journal of

Volume 2018

Zoology

Hindawiwwwhindawicom Volume 2018

Anatomy Research International

PeptidesInternational Journal of



Journal of Parasitology Research

GenomicsInternational Journal of


Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018


BioinformaticsAdvances in

Marine BiologyJournal of



Neuroscience Journal


BioMed Research International

Cell BiologyInternational Journal of



Biochemistry Research International

ArchaeaHindawiwwwhindawicom Volume 2018


Genetics Research International


Advances in

Virolog y Stem Cells International



Enzyme Research



MicrobiologyHindawiwwwhindawicom

Nucleic AcidsJournal of

Volume 2018

Submit your manuscripts atwwwhindawicom

in suspension [13] erefore noble metal nanoparticlesdoping on titania with improved crystallinity surface area andsurface properties to achieve higher adsorption capacity andphotocatalytic activity [14] have been studied extensively suchas metal-titania nanoparticles coated on the high surface areasupports and thermally stable core materials [15 16] Nano-porous materials such as ordered mesoporous silica [17ndash19]activated carbon [20 21] microporous zeolites [22 23] andmetal organic frameworks [24 25] have been widely used asTiO2 carriers due to their versatile structures and high porosityto achieve more active sites per unit area consequentlya higher photocatalytic reaction rate Mesoporous alumino-silicate Al-MCM-41 is one of the most widely used supportmaterials due to its remarkable acidic properties high thermaland mechanical stability highly ordered hexagonal structureand high surface area [26ndash30] Recent studies have focused onthe use of low-cost raw materials particularly in their naturalforms such as bentonite clay to synthesize high value productse inorganic components consisting of silica and aluminawere collected by annealing bentonite with sodium hydroxideat a temperature higher than 500degC to use for the synthesis ofAl-MCM-41 [31 32] Herein the Al-MCM-41 mesoporousmaterial was prepared by a hydrothermal method using theVietnamese bentonite as Si and Al precursors en AgTiO2nanoparticles were deposited on the surface of the Al-MCM-41material to improve the dispersion of TiO2 and the synthesizedAl-MCM-41AgTiO2 nanocomposites were used as a pho-tocatalyst for the oxidative desulfurization of dibenzothio-phene under both UV and visible light irradiation

2 Experimental

21 Chemicals Dibenzothiophene (DBT) triblock PluronicF127 (EO106PO70EO106 99 wtM 12600) titanium (IV)isopropoxide (TTIP 97 wt) n-octane (99 wt) silvernitrate (99 wt) cetyltrimethylammonium bromide(CTAB 98 wt) ethanol (995 wt) acetic acid (99 wt)hydrogen peroxide (30wt) and NaOH (98wt) werepurchased from either Sigma-Aldrich or Merck Bentonitewas obtained from Di Linh Vietnam with a chemicalcomposition of 52 SiO2 15 Al2O3 11 Fe2O3 08 TiO2 2CaO 35 MgO 2 Na2O in weight percent and the loss onignition (LOI) of 137

22 Synthesis of Al-MCM-41 from Vietnamese BentoniteFirstly Si and Al precursors were obtained following theprotocol described by Ali-dahmane et al [31] e Viet-namese bentonite was mixed with sodium hydroxide(NaOH) in bentonite NaOH weight ratio of 1 12 andheated at 550degC for 3h in air e fused bentonite obtainedwas cooled milled mixed with distilled water with a weightratio of 1 4 and then stirred at room temperature for 24 he supernatant was separated by centrifugation to obtainthe Si and Al precursors

In a typical Al-MCM-41 synthesis 12 g CTAB wasadded to 20mL distilled water en 42mL of the super-natant was added to the above solution and stirred at roomtemperature for 6 h at pH of about 9-10 which was adjusted

by acetic acid e crystallization step was carried out at100degC in a stainless steel autoclave for 24 hours e whiteprecipitate was then filtered and washed three times withdistilled water and ethanol and dried overnight at 100degCFinally the template CTAB was removed by calcining at550degC for 6 h in air

23 Synthesis of Al-MCM-41nAgTiO2 NanocompositeAl-MCM-41nAgTiO2 nanocomposite microspheres weresynthesized by a sol-gel method 01 g of the synthesized Al-MCM-41 was dispersed in 100mL ethanol via sonication for1 h en 02 g F127 and 2mL distilled water were added tothe above solution e mixture was stirred at 50degC for 30minutes

A TiO2 precursor (solution A) was prepared by dis-solving titanium(IV) isopropoxide (TTIP) in a mixed sol-vent of ethanol and nitric acid to form a final composition of1 TTIP C2H5OH 2 H2O 02 HNO3 Solution B was pre-pared by adding n (n 5 10 and 15) moles of AgNO3into 15mL ethanol and stirred for 30 minutes en so-lution A was mixed with solution B and stirred vigorouslyfor 30 minutes e AgTiO2 precursor was added dropwiseto the Al-MCM-41 suspension to obtain Al-MCM-41nAgTiO2 e temperature was then increased to 80degCunder refluxing conditions for 6 he solid was collected bycentrifugation and washed thoroughly with ethanol anddried at 80degC Finally F127 was removed by calcining theobtained solid at 450degC in air for 5 h

24 Oxidative Photodesulfurization of DibenzothiopheneDibenzothiophene was dissolved in n-octane to createa model fuel with known sulfur content in ppm Next 20mLof DBTn-octane solution was placed in a 500ml three-neckround-bottom flask containing 005 g catalyst e suspen-sion was stirred for 30 minutes in the dark and then wasilluminated with two 15W UV lamps (UV light) or a 165Wtungsten lamp (visible light) at various temperatures (30degC50degC and 70degC) under refluxing conditions for 5 h 05mL ofH2O2 as an oxidative agent was added to the mixture at thereaction temperatures After certain reaction time smallamounts of the products were taken out centrifuged andanalyzed by high-performance liquid chromatography(HPLC) en peak areas were converted to their corre-sponding concentrations through the standard curves epercentage of degradation of DBT (η) was calculatedaccording to the initial C0 (ppm) and final C (ppm)concentrations of DBT in the solution following thisequation η 100 times (C0 ndashC)C0

25 Characterization Powder X-ray diffraction (XRD)patterns were recorded on a D8-Advance Bruker with Cu-Kα radiation (λ 015406 nm) as the X-ray source at a scanrate of 03degndash06degminminus1 Transmission electron microscopy(TEM) images were taken by a TEM TECNAI G 2 20 with anaccelerating voltage of 200 kV Scanning electron microscopy(SEM) images were obtained on an S4800-Hitachi Pore sizedistributions were calculated from N2 isotherms using the










αh] Ah]minusEg1113872 1113873n2

(1)


10 20 30 40 50 60 70

(204)(211)(200)(004)

(e)

(d)

(b)

(c)

Inte

nsity

(au

)2 Theta (degree)

(a)

(101)1 2 3 4 5 6 7 8 9 10

(200)(110)

(a)

(b)(c)

(d)

2 Theta (degree)

(e)

(100)

Inte

nsity

(au

)






(a) (b)


(a) (b)


300 400 500 600 700 800

Abs

orba

nce (

au)

Wavelength (nm)




middotmiddot

middot

middot





0 1 2 3 4 5 6 7 8 9 10

Ti

Ti

Ti

Si

Al Ag

O



00 02 04 06 08 100

100

200

300

400

500

600

(b)Ads

orpt

ion

volu

me (

cm3 g

)


(a)



16

14

12

10

8

6

4

2

01200

Inte

nsity

(au

)


times104

Ti2a

Ti2p

Ag3d

O1s C1s

Ti3a

Ti3pSi2p Si2a

(a)

210

200

190

180

170

Inte

nsity

(au

)

160

150

140

130

120

Binding energy (eV)

Ag3d

384 380 376 372 368 364 360

times101

(b)

40

times102

35

30

25

20

15

476 472 468 464 460 456 452 448

Ti2p

Inte

nsity

(au

)

Binding energy (eV)

(c)


0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersin

of D

BT (

)

Reaction time (h)













Ag+ h+





4 Conclusions



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC





Data Availability




Acknowledgments




References





















































Volume 2018

Zoology











Volume 2018

















Advances in




Enzyme Research





Volume 2018










αh] Ah]minusEg1113872 1113873n2

(1)


10 20 30 40 50 60 70

(204)(211)(200)(004)

(e)

(d)

(b)

(c)

Inte

nsity

(au

)2 Theta (degree)

(a)

(101)1 2 3 4 5 6 7 8 9 10

(200)(110)

(a)

(b)(c)

(d)

2 Theta (degree)

(e)

(100)

Inte

nsity

(au

)






(a) (b)


(a) (b)


300 400 500 600 700 800

Abs

orba

nce (

au)

Wavelength (nm)




middotmiddot

middot

middot





0 1 2 3 4 5 6 7 8 9 10

Ti

Ti

Ti

Si

Al Ag

O



00 02 04 06 08 100

100

200

300

400

500

600

(b)Ads

orpt

ion

volu

me (

cm3 g

)


(a)



16

14

12

10

8

6

4

2

01200

Inte

nsity

(au

)


times104

Ti2a

Ti2p

Ag3d

O1s C1s

Ti3a

Ti3pSi2p Si2a

(a)

210

200

190

180

170

Inte

nsity

(au

)

160

150

140

130

120

Binding energy (eV)

Ag3d

384 380 376 372 368 364 360

times101

(b)

40

times102

35

30

25

20

15

476 472 468 464 460 456 452 448

Ti2p

Inte

nsity

(au

)

Binding energy (eV)

(c)


0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersin

of D

BT (

)

Reaction time (h)













Ag+ h+





4 Conclusions



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC





Data Availability




Acknowledgments




References





















































Volume 2018

Zoology











Volume 2018

















Advances in




Enzyme Research





Volume 2018





(a) (b)


(a) (b)


300 400 500 600 700 800

Abs

orba

nce (

au)

Wavelength (nm)




middotmiddot

middot

middot





0 1 2 3 4 5 6 7 8 9 10

Ti

Ti

Ti

Si

Al Ag

O



00 02 04 06 08 100

100

200

300

400

500

600

(b)Ads

orpt

ion

volu

me (

cm3 g

)


(a)



16

14

12

10

8

6

4

2

01200

Inte

nsity

(au

)


times104

Ti2a

Ti2p

Ag3d

O1s C1s

Ti3a

Ti3pSi2p Si2a

(a)

210

200

190

180

170

Inte

nsity

(au

)

160

150

140

130

120

Binding energy (eV)

Ag3d

384 380 376 372 368 364 360

times101

(b)

40

times102

35

30

25

20

15

476 472 468 464 460 456 452 448

Ti2p

Inte

nsity

(au

)

Binding energy (eV)

(c)


0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersin

of D

BT (

)

Reaction time (h)













Ag+ h+





4 Conclusions



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC





Data Availability




Acknowledgments




References





















































Volume 2018

Zoology











Volume 2018

















Advances in




Enzyme Research





Volume 2018






0 1 2 3 4 5 6 7 8 9 10

Ti

Ti

Ti

Si

Al Ag

O



00 02 04 06 08 100

100

200

300

400

500

600

(b)Ads

orpt

ion

volu

me (

cm3 g

)


(a)



16

14

12

10

8

6

4

2

01200

Inte

nsity

(au

)


times104

Ti2a

Ti2p

Ag3d

O1s C1s

Ti3a

Ti3pSi2p Si2a

(a)

210

200

190

180

170

Inte

nsity

(au

)

160

150

140

130

120

Binding energy (eV)

Ag3d

384 380 376 372 368 364 360

times101

(b)

40

times102

35

30

25

20

15

476 472 468 464 460 456 452 448

Ti2p

Inte

nsity

(au

)

Binding energy (eV)

(c)


0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersin

of D

BT (

)

Reaction time (h)













Ag+ h+





4 Conclusions



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC





Data Availability




Acknowledgments




References





















































Volume 2018

Zoology











Volume 2018

















Advances in




Enzyme Research





Volume 2018


16

14

12

10

8

6

4

2

01200

Inte

nsity

(au

)


times104

Ti2a

Ti2p

Ag3d

O1s C1s

Ti3a

Ti3pSi2p Si2a

(a)

210

200

190

180

170

Inte

nsity

(au

)

160

150

140

130

120

Binding energy (eV)

Ag3d

384 380 376 372 368 364 360

times101

(b)

40

times102

35

30

25

20

15

476 472 468 464 460 456 452 448

Ti2p

Inte

nsity

(au

)

Binding energy (eV)

(c)


0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersin

of D

BT (

)

Reaction time (h)













Ag+ h+





4 Conclusions



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC





Data Availability




Acknowledgments




References





















































Volume 2018

Zoology











Volume 2018

















Advances in




Enzyme Research





Volume 2018










Ag+ h+





4 Conclusions



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC



0

20

40

60

80

100

0 1 2 3 4 5

Conv

ersio

n of

DBT

()


30degC50degC70degC





Data Availability




Acknowledgments




References





















































Volume 2018

Zoology











Volume 2018

















Advances in




Enzyme Research





Volume 2018



Data Availability




Acknowledgments




References





















































Volume 2018

Zoology











Volume 2018

















Advances in




Enzyme Research





Volume 2018



























Volume 2018

Zoology











Volume 2018

















Advances in




Enzyme Research





Volume 2018




Volume 2018

Zoology











Volume 2018

















Advances in




Enzyme Research





Volume 2018


Documents

SynthesisofAl-MCM-41@Ag/TiO NanocompositeandIts ...downloads.hindawi.com/journals/jchem/2018/8418605.pdf · ResearchArticle SynthesisofAl-MCM-41@Ag/TiO 2NanocompositeandIts PhotocatalyticActivityforDegradationofDibenzothiophene