research article photocatalytic degradation of eosin...

Research ArticlePhotocatalytic Degradation of Eosin Yellow UsingPoly(pyrrole-co-aniline)-Coated TiO

2Nanocellulose

Composite under Solar Light Irradiation

T S Anirudhan and S R Rejeena

Department of Chemistry University of Kerala Kariavattom Trivandrum 695 581 India

Correspondence should be addressed to S R Rejeena rejeenasrgmailcom

Received 8 June 2015 Revised 26 August 2015 Accepted 6 September 2015

Academic Editor Carmen Alvarez-Lorenzo

Copyright copy 2015 T S Anirudhan and S R Rejeena This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

The present study describes the feasibility of a novel adsorbent cum photocatalyst poly(pyrrole-co-aniline)-coated TiO2nano-

cellulose composite (P(Py-co-An)-TiO2NCC) to remove eosin yellow (EY) from aqueous solutions The removal of EY was

investigated by batch adsorption followed by photocatalysis The effect of various adsorption parameters like adsorbent dose pHcontact time initial concentration and ionic strength has been optimized for treating effluents from the dye industry Adsorptionof EY reachedmaximum at pH 45 and complete removal of dye was achieved using 35 gL of P(Py-co-An)-TiO

2NCC Adsorption

equilibrium data were fitted with Langmuir and Fritz-Schlunder isothermmodels and the kinetics of adsorption follows a second-order mechanismThe adsorption capacity of P(Py-co-An)-TiO

2NCC was found to be 339 times 10minus5molg and reached equilibrium

within 90min The photocatalytic degradation of adsorbed dye under sunlight was possible and about 923 of dye was degradedwithin 90min The reusability of P(Py-co-An)-TiO

2NCC was also investigated The results indicate that P(Py-co-An)-TiO

2NCC

is the best material for the wiping out of EY from aqueous solutions

1 Introduction

Textile dyes are the largest group of chemicals being producedall over the world The effluents from manufacturing andtextile industries are discarded in large quantities into riversand lakes causing water pollution and affect the ecosystemseriously [1] So the dye removal has been consideredas a challenging problem for environmental scientists [2]The developed dye removal strategies include biologicaltreatment coagulation flotation adsorption oxidation andelectrochemical techniques [3] Adsorption is a preferredmethod due to its high efficiency ease of handling andthe availability of low cost adsorbents [4] However it hasbeen reported that the majority of dyes are only adsorbedand are not degraded and are also ineffective that theysimply transfer the pollutants to another phase rather thandestroying them [5] Photocatalysis for the purification ofwastewater from industries and households has attractedmuch attention in recent years Photocatalytic degradation

relies on the technology of advanced oxidation processes(AOPs) in which electron-hole pair radicals able to undergosecondary reactions are created [6]

TiO2has been extensively used as a photocatalyst owing

to its inexpensive nontoxic and photoelectric properties[7] It can also be used in harsh conditions for its highchemical and thermal stability However lack of recyclabilityand low adsorption ability for the pollutants especially forthe nonpolar organic compounds are the disadvantagesfaced while using bare TiO

2 Organic molecules which can

effectively adsorb to the surface of the photocatalyst willbe more susceptible to direct oxidation [8] Nano-TiO

2is

an active material which has advantages such as innocuityresisting and decomposing bacteria UV resistance andsuperhydrophilicity [9]

Anchoring of TiO2on various supports including carbon

glass fibers montmorillonite organic materials and zeolitesmay increase their photochemical stability Organicmaterialswith UV light resistance have been widely used as supports

Hindawi Publishing CorporationJournal of MaterialsVolume 2015 Article ID 636409 11 pageshttpdxdoiorg1011552015636409

2 Journal of Materials

for TiO2photocatalyst since they have the advantages such

as low cost and easy separation from reaction solutionCellulose obtained from wood pulp and cotton is such amaterial used for this purpose due to its low cost and easyavailability Cellulose has been explored as a substrate forcomposite materials because of the presence of functionalgroups that may be employed in various activation processesAdditionally it was suggested that the holesrsquo scavengingability increases with the increasing number and spatialdistribution of the hydroxyl groups in the polyhydroxylcompounds [10] When cellulose is converting to theirnanocrystals the holesrsquo scavenging ability increases due to thelarge number of hydroxyl groups exposed to the surface Thenanocellulose ismechanically strong and produced a strengthof 25 that of carbon nanotubes [11]

Conducting polymers such as polypyrrole polyanilineand polythiophene have functioned as dopants which shiftthe border of the TiO

2particles to longer wavelengths

thereby improving the optical absorption in the visibleregion These hybrid conducting polymerTiO

2composites

exhibit excellent properties unlike those of the individualmaterials such as controlled conductivity and thermal ormechanical stability and these properties have made thempotentially applicable as anode materials for lithium-ionbatteries [12] anode electrodes for dye solar cells [13] orphotocatalytic materials [14]The conjugated polymers couldbe separated from the aqueous phase by using simple gravitysettling and could be recycled easily The conjugated poly-mers have an extended conjugation system and behave likesemiconducting materials with low charge carrier mobilityPolyaniline (PAn) has been deposited on various materialsto perform desired applications [15] Polypyrrole (PPy) hasa potential application in the field of composite materials dueto their appreciable environmental stability higher electricalconductivity easier synthesis and solubility in differentsolvents [16]

As we know eosin yellow (EY) is widely used for stainingpurposes however it is listed as a carcinogen The presentwork is aimed at wiping out the textile dye EY from theenvironment for the well-being of the organisms In thepresent work a novel polymer composite poly(pyrrole-co-aniline)-coated TiO

2nanocellulose composite [P(Py-co-

An)-TiO2NCC] was prepared for the adsorptive removal

of EY from aqueous solutions followed by photocatalyticdegradation under sunlight For the preparation of thispolymeric hydrogel glutaraldehyde the agent widely used forindustrial water treatment and a preservative was selected asa crosslinker

2 Materials and Methods

21 Materials Sawdust of Mangifera indica was a kind giftfrom Local Saw mill Trivandrum Titanium(IV) isopropox-ide (97) eosin yellow (EY) pyrrole (Py) aniline (An) andglutaraldehyde were purchased from SigmaAldrich H

2S2O4

NaOH HNO3 FeCl

3 H2O2 ethanol HCl and ammonium

persulfate (APS) were received from E Merck India All thechemicals were used without further purification Deionized

water was used in preparing the aqueous stock solutions forthe adsorption-photocatalytic experiments

22 Preparation of P(Py-co-An)-TiO2NCC

221 Extraction of Nanocellulose (NC) from Sawdust Cellu-lose has been extracted from sawdust and was converted tonanocrystals following the procedure reported earlier [17]Briefly sawdust was pretreated with 10 H

2SO4solution

(120∘C 10min) and centrifuged to remove rich pentosanssolution Delignification was achieved by the subsequenttreatment with 1 NaOH (100∘C 1 h) The obtained brownmass upon bleaching with 5 H

2O2(80∘C 1 h) yielded

white cellulose About 5 g of cellulose was dispersed in250mL distilled water under magnetic stirring (20min)140mL 98 sulfuric acid was dropped to the homogenizedmixture without causing heating After complete additionthe mixture was heated at 50∘C for 2 h The hot mixture wasdiluted ten times with ice cooled distilled waterThe obtainedwhite colloidwas centrifuged washedmany timeswithwaterand freeze-dried

222 Preparation of TiO2NC Composite (TiO2NCC) NC(02 g) HNO

3(5mL 01M) and absolute ethanol (100mL)

were mixed with each other and the mixture was ultrasoni-cally dispersed for 1 h After dispersion 1mL of titanium(IV)isopropoxide was added to this mixture slowly with a con-stant pressure funnel under magnetic stirring The reactiontemperature was kept at 40∘C for 4 h Finally the suspensionwas diluted fivefold with water centrifuged and then washedwith water repeatedly The precipitate was dialyzed againstdeionized water for 2 days and then freeze-dried

223 Preparation of P(Py-co-An)-TiO2NCC P(Py-co-An)-TiO2NCC was synthesized by chemical oxidation of its

respective monomers Py and An by keeping their molarratios constant at 1 1 The aqueous solution of TiO

2NCC

(240mg in 100mL) was mixed with a solution of pyrrole(3mL) aniline (3mL) and HCl (37 016mL) for 30minwhere after APS (046 g) and of FeCl

3(80 g) was added

respectively in the solution for polymerization initiationand stirred for 3 h The obtained product with a layer ofpoly(pyrrole-co-aniline) was filtered washed with ethanoland dried at 50∘CThe dried product designated as P(Py-co-An)-TiO

2NCC was sieved to get an average particle size of

0096mmand used for adsorption followed by photocatalyticexperiments

23 Characterization of P(Py-co-An)-TiO2NCC Surfacemorphology of the adsorbents was investigated by SEMmicrographs recorded with a JEOL JSM 6390 LA scanningelectron microscope The Brunauer-Emmett-Teller (BET)surface area was determined using a model Q7S surfacearea analyzer (Quantasorb USA) The XRD patterns wererecorded using XrsquoPert Pro X-ray diffractometer Patternswere recorded in the 2120579 range of 10ndash70 at a scan rate of2 countss The FTIR spectra of adsorbents were recorded onKBr pellets with FTIR spectrophotometer in the wavelength

Journal of Materials 3

range of 550ndash4000 cmminus1 (Shimadzu Japan) Dried sampleweighing 10mg was dispersed in 200mg of spectroscopicgrade KBr to record the spectra at a resolution of 4 cmminus1JASCO UV-visible (model V-550) spectrophotometer wasused for the estimation of dye concentration in the solutionand gel

24 Adsorption of EY Adsorption experiments were con-ducted to evaluate adsorption capacities of P(Py-co-An)-TiO2NCC A stock solution of EY (10minus2M) was prepared in

1 L of double distilled waterThe desired concentrations of thedye solution were obtained by proper dilution of the stocksolution 01 g of P(Py-co-An)-TiO

2NCC was added into a

stoppered bottle containing 50mL of EY solution (10minus5M)pH of the solution was adjusted to the desired value withdilute HCl or NaOH The mixture was shaken at 30∘C for90min for adsorption and then the mixture was filteredTheconcentration of the dye solution before and after adsorptionwas estimated using UV-visible spectroscopic method Theadsorption () and the amount adsorbed (molg) werecalculated as follows

Adsorption () =(1198620minus 119862119890)

1198620

times 100

119902119890= (1198620minus 119862119890) times

119881

119898

(1)

where 1198620and 119862

119890(molL) are the concentrations of EY

solution before and after adsorption respectively 119902119890is

the adsorption capacity of the adsorbent 119881 (mL) is thevolume of the EY solution and 119898 (g) is the mass of theadsorbent Adsorbent dose experiments were conducted byshaking 10minus5M dye solution with 01ndash10 g of P(Py-co-An)-TiO2NCCAdsorption kineticswas obtained by determining

the adsorption capacity at different time intervals from 5 to240min Adsorption isotherm was studied by changing theconcentrations of the dye solution from 10minus5 to 10minus4M

25 Photocatalytic Degradation of EY and the Regenerationof the Photocatalyst Photocatalytic degradation of the dyewas studied using P(Py-co-An)-TiO

2NCC after adsorption

experiment The dye loaded swollen hydrogels were exposedto sunlight (at noon) and withdrawn at different time inter-vals from 5 to 120min Each sample is then analyzed spec-trophotometrically at a wavelength of 515 nm Degradationrate was calculated from the amount of the dye in the swollengels as follows

Degradation ratio () =(1198620minus 119862119890)

1198620

times 100 (2)

where 1198620and 119862

119890are the initial and equilibrated concentra-

tions of the dye (molL)The samples obtained after photocatalytic degrada-

tion were washed thoroughly and adsorption-photocatalyticdegradation experiments were repeated for four cycles inorder to perform their regeneration capacity

3 Results and Discussion

31 Preparation of the Photocatalyst P(Py-co-An)-TiO2NCCThe photocatalyst P(Py-co-An)-TiO

2NCC was prepared

from TiO2NCC via chemical oxidation polymerization

technique Firstly Cellulose was extracted from the valueadded product sawdust by acid-alkali treatment followed bybleaching with H

2O2 The cellulose was made into nanocrys-

tals via acid hydrolysis which improves its crystallinity andhydrophilicity TiO

2NCC was prepared from NC and the

precursor Ti(OiPr)4using chemical precipitation method

PPy and PAn were coated onto TiO2NCC by chemical oxi-

dation polymerization of pyrrole and aniline with FeCl3 APS

will generate TiO∙ free radicals and the polymer chain getsattached to itThe presence of the crosslinker glutaraldehydewill create a three-dimensional network structure therebyincreasing thewater or solute holding capacity of thematerial

32 Characterization Studies

321 Surface Morphology Analysis The surface morphologyof the samples is clearly displayed in Figure 1The SEM imageof the cellulose was observed to be smooth and fibrous andto have a layered structure which provided a good conditionfor the adsorption of the dye pollutants NC seems to behydrophilic and behaves as gel structure It may increasethe swelling and diffusion of solute molecules from aqueousphase TiO

2NCC composite showed TiO

2particles to be

well dispersed and so reside equally on all regions on thesurfaceThepolymerization ontoTiO

2NCC (Figure 1(d)) led

to a heterogeneous rough surface and this surface roughnessleads to different prominent adsorption phases during theadsorption process [18]

322 XRD Analysis Figure 2 shows the XRD patterns ofcellulose NC TiO

2NCC and P(Py-co-An)-TiO

2NCCThe

XRD pattern of cellulose shows peaks at 2120579 values of 221 and342∘ correspond to crystalline domain of cellulose structurewhereas the broad hump at 158∘ indicates the amorphousnature of cellulose The small shift and the increase in broad-ness of the characteristic peaks of NCmay be due to the smallparticle size of NCThe sharper diffraction peaks of NC werearoused due to the partial removal of the amorphous regionsduring the acid hydrolysis treatment of cellulose [19] Theidentified XRD patterns of TiO

2NCC gave distinctive peaks

at sim256 382 482 546 and 634∘ (JCPDS card number21-1272) which resemble the characteristic peaks of TiO

2

as given in earlier reports [7] From Figure 2 it is observedthat the crystalline peaks are relatively broad compared tothose normally obtained for bulkmaterial indicating that thecrystal sizes are smaller The Debye-Scherrer equation [20] isused to determine the average crystal size of the NC and it isfound to be in the range of 216 nm The appearance of newpeaks and the shifting of the characteristic peaks of TiO

2in

P(Py-co-An)-TiO2NCC clearly indicate that proper grafting

had been occurring on the surface of TiO2NCC

323 FTIR Analysis The FTIR patterns of cellulose NCTiO2NCC and P(Py-co-An)-TiO

2NCC are presented in


(d)(c)

(b)(a)

Figure 1 SEM photographs of (a) cellulose (b) NC (c) TiO2NCC and (d) P(Py-co-An)-TiO

2NCC

234

256

382

482

546

634

161

101

220

342

159

226

339

159

54222

8

188

671

167

253

382

457

476

520

642

119

20 30 40 50 60 7010

2120579 (deg)

CelluloseNC

P(Py-co-An)-TiO2NCCTiO2NCC

Figure 2 XRD patterns of cellulose NC TiO2NCC and P(Py-co-An)-TiO

2NCC


tr

ansm

ittan

ce (a

u)

3318

11121642

539

1540

1035

1745

1643

1058

Wavenumber (cmminus1)

3441 2922

3417

1033

1636

2899

2356

1697

1457

5493753 18

68

1041

5001000150020002500300035004000

CelluloseNC


Figure 3 FTIR spectra of cellulose NC TiO2NCC and P(Py-co-

An)-TiO2NCC

Figure 3 The peaks observed at sim3441 and 3417 cmminus1 arederived from hydroxyl groups in cellulose and water Thebands at sim2922 and 2899 cmminus1 (C-H stretching of CH

2)

and 1426 cmminus1 (CH2symmetric bending) can be assigned

to the stretching and bending modes of hydrocarbons incellulose backbone [21] The characteristic peaks of cellulosicmaterial also appeared at 1112 and sim1033 cmminus1 (skeletal vibra-tions involving C-O stretching) [22] The peak at sim539 cmminus1clearly shows the presence of discrete anatase particles inTiO2NCC structure [23] The two characteristic peaks at

1554 and 1492 cmminus1 in P(Py-co-An)-TiO2NCC correspond

to the frequencies of aromatic ring in PAn which arestretching of quinine ring and benzene rings respectively[24] Peaks attributed to out-of-plane bending vibration ofC-H band of parasubstituted benzene ring were observednear 755 cmminus1 and the stretching of C-N band of benzenering was confirmed by the peak of 1267 cmminus1 [25] The bandat 1457 cmminus1 may be attributed to C-N stretching modes ofvibration in pyrrole ring The peak nearer to sim3318 cmminus1found in TiO

2NCC was not observed after polymerization

which suggests that polymerization had occurred due tothe breakage of intermolecular hydrogen bond present inTiO2NCC

33 Adsorption Studies

331 Effect of Adsorbent Dose The amount of the spentadsorbent determines the economic value of the adsorp-tion process The performances of the adsorbent P(Py-co-An)-TiO

2NCC and the precursor material cellulose were

Adso

rptio

n (

)

Adsorbent dose (gL)

100

80

60

40

20

011109876543210

Tio2NCCP(Py-co-An)-g-TiO2NCC

Equilibrium time 2hTemperature 30∘CInitial concentration 10 times 10minus5 MpH 45

Figure 4 Effect of adsorbent dose on EY adsorption onto P(Py-co-An)-TiO

2NCC

evaluated by varying their amounts from 05 to 50 gLAs seen in Figure 4 the adsorption percentage of the sor-bents increases with increase in amount because of theincreased available surface sites for adsorption [26] Thecomplete removal of EY was achieved with an amount ofTiO2NCC 90 gL and P(Py-co-An)-TiO

2NCC 35 gL

respectively It means that the sorption efficiency of P(Py-co-An)-TiO

2NCC is 26 times more than the untreated

cellulose at pH 45 The variation in the adsorption capacitybetween the various adsorbents could be related to the natureand concentration of surface groups responsible for theinteraction with the dyes

332 Effect of Solution pH pH value of the solution is animportant controlling parameter in the adsorption processsince it affects the surface charge of the adsorbent and thedegree of speciation of adsorbate As depicted in Figure 5adsorption of EY on P(Py-co-An)-TiO

2NCC was strongly

affected by the solution pH As pH of the solution wasincreased from 20 to 90 the percentage adsorption increasesand reachesmaximumat pH45 and thereafter decreasesThemaximum dye removal () at pH 45 was found to be 917for an initial EY concentration of 10 times 10minus5MThe increaseduptake at much higher acidic solution can be attributed tothe increasing electropositive charge of the adsorbent whichfavored the adsorption of dye anions through electrostaticattraction (Figure 6) At pH lt 45 the aniline surfaces werepositively charged and at pH gt 45 the surfaces were neg-atively charged Aniline can exist as nondissociated andordissociated species in aqueous solutions Aniline is an ioniz-able organic compound and is a weak base that can protonateto form anilinium ion Thus the high efficient removal ofEY by P(Py-co-An)-TiO

2NCC is due to its high porosity

great surface area and intrinsic positive charge of P(Py-co-An)-TiO

2NCC as a type of n-doping polymer in which the

anionic dopant (Clminus) is exchanged by the anionic dye


Table 1 Kinetic parameters for the adsorption of EY onto P(Py-co-An)-TiO2NCC (plusmnstandard deviation 119899 = 3)

1198620times 10minus5

(mol Lminus1)119902119890 exp times 10minus5

(mol gminus1)

Pseudo-first-order Pseudo-second-order

1198961(minminus1) 119902119890 cal times 10

minus5

(mol gminus1) 11987721205942 119896

2

(gmolminus1minminus1)119902119890 cal times 10minus5(mol gminus1) ℎ0 times 10

minus611987721205942

1 0458 0270 0447 0974 00003 1234 0461 0262 0995 7 times 10minus5

5 2202 0279 2157 0977 0007 0003 2218 0015 0996 00014

Temperature 30∘C

Initial concentration 10 times 10minus5 MEquilibrium time 90min

Adsorbent dose 2gL

3 4 5 6 7 8 92

pH

65

70

75

80

85

90

95

100

105

Adso

rptio

n (

)

Figure 5 Effect of solution pHonEY adsorption onto P(Py-co-An)-TiO2NCC

333 Effect of Adsorption Time Figure 7 shows the effectof contact time on the batch adsorption of EY at 30∘Cand pH 45 It is obvious that the increase in contact timefrom 5 to 90min increased the percentage removal of EYThis is due to the large number of active binding sites foradsorption during the initial stage and gradual occupancyof them makes the sorption less efficient in the later stages[27] A further increase in contact time had a negligible effecton the percentage removal of EY It implies that the sorptionprocess is considerably fast andmore than 917 and 881 ofdye solution with initial concentrations of 10 times 10minus5 and 50times 10minus5M respectively were adsorbed within 90min

Adsorption Kinetics To perform the adsorption process ona larger scale the elucidation of kinetic parameters and thesorption characteristics of the adsorbent are required Withthat purpose we analyzed the experimental kinetic data withpseudo-first-order and pseudo-second-order equations (see(3))The first-order kineticsmodel assumesmass transport asthe rate limiting mechanism whereas the second-order oneassumes chemical adsorption as the rate limitingmechanismConsider

Pseudo-first-order 119902119905= 119902119890(1 minus 119890

minus1198961119905)

Pseudo-second-order 119902119905=

1198962119902119890

2119905

1 + 1199051198962119902119890

(3)

where 119902119890and 119902

119905(mgg) are the amount of dye adsorbed on

P(Py-co-An)-TiO2NCC at equilibrium and time 119905 (min)

respectively 1198961(minminus1) is the rate constant for the pseudo-

first-order adsorption process 1198962(g molminus1minminus1) is the rate

constant for the pseudo-second-order kineticsAdditionally the initial adsorption rateℎ

0(mol gminus1minminus1)

can be calculated frompseudo-second-order kineticmodel asfollows

ℎ0= 1198962119902119890

2 (4)

Kinetic parameters for different concentrations werecalculated by a nonlinear curve fittingmethod usingORIGINprogram (version 75) and are listed in Table 1 The computedvalues of correlation coefficient (1198772) and chi-square (1205942)values measure the degree of fitness of the model with theexperimental kinetic data Higher 1198772 (gt099) and lower 1205942values obtained for the pseudo-second-order model indicatethat this model could define the experimental results moreprecisely than pseudo-first-order model which indicates thatthe rate-limiting step may be a chemical sorption involvingvalence forces through exchange of ions between the adsor-bent and adsorbate As the initial dye concentration increasesthe initial adsorption rate (ℎ

0) increasesThe values of 119896

2were

found to be decreased with increase of initial concentrationand may be due to lowering the probability of collisionbetween the dye molecules which faster the movement of dyetowards the adsorbent surface at lower concentrations

334 Effect of Solute Concentration Adsorption isothermmeasures the adsorption efficiency of a polymer over a rangeof analyte concentrations It describes the interactive behav-ior between adsorbate and adsorbent and is important forpredicting the adsorption capacity of adsorbent which is themain parameter required for design of an adsorption systemThe increase in concentration of dye solution caused anincrease in adsorption capacity (Figure 8) since the increasein initial dye concentration facilitates the dyemovement frombulk to the surface of the adsorbent

For evaluating the maximum adsorption capacity andadsorptionmechanism the experimental isotherm data wereinterpreted using the equilibrium isotherm models such asLangmuir Freundlich and Fritz-Schlunder isotherm equa-tions as follows

119902119890=

1198760119887119862119890

1 + 119887119862119890

119902119890= 119870F119862119890

1119899

119902119890=

119902FS119870FS1198621198901 + 119902FS119862119890

120572

(5)


NH

NH

NH

n

n

C-

O

O O

BrBr

BrBr

HN

Electronic interaction

Hydrogen-bonding interaction

minusO

Ominus

++

Figure 6 Possible interactions between EY and P(Py-co-An)-TiO2NCC

Pseudo-first-orderPseudo-second-order

Time (min)240220200180160140120100806040200

00

05

10

15

20

25

30

35

qetimes10

minus5

(mol

g)

50 times 10minus5 M10 times 10minus5 M

Experimental

pH 45Temperature 30∘C

Adsorbent dose 2gL

Figure 7 Kinetic modeling for the EY adsorption onto P(Py-co-An)-TiO

2NCC

where 119902119890(molL) is the amount adsorbed at equilibrium

119862119890(molL) is the equilibrium concentration of the dye on

adsorption 1198760 (molg) is the maximum adsorption capacityat complete monolayer and 119887 (Lmol) is the Langmuir con-stant related to the affinity of binding sites and is a measure

of the energy of adsorption 119870F (mol1minus1119899 L1119899g) and 1119899are the Freundlich constants related to adsorption capacityand intensity of adsorption respectively 119902FS is the Fritz-Schlunder maximum adsorption capacity (molg) 119870FS is theFritz-Schlunder equilibrium constant (Lmol) and 120572 is theFritz-Schlunder exponent

The Langmuir isotherm [28] is based on assumption ofstructurally homogeneous adsorbent and monolayer cov-erage with no interaction between the sorbate moleculesAccording to this model once a dye molecule occupiesa site no further adsorption can take place at that site[29] The Langmuir parameters can be used to predict theaffinity between the sorbate and sorbent using dimensionlessseparation factor (119877L)

119877L =1

1 + 1198871198620

(6)

where 119887 is the Langmuir isothermconstant relating to bindingenergy and 119862

0is the initial solute concentration The values

of 119877L at 30∘C were determined and were found to be 02874

01678 01185 00916 00746 00629 00545 00479 00429and 00387 at an initial dye concentration of 1 2 3 4 5 6 7 89 and 10 times 10minus5mgL respectively 119877L values for the presentexperimental data fell between 0 and 1 which is indicativeof favorable adsorption of EY onto P(Py-co-An)-TiO

2NCC

The maximum monolayer adsorption capacity based onLangmuir model was 3397molg The adsorption capacityof the adsorbent P(Py-co-An)-TiO

2NCC towards EY was


Table 2 Isotherm parameters for the adsorption of EY onto P(Py-co-An)-TiO2NCC at 30∘C (plusmnstandard deviation 119899 = 3)

Langmuir Freundlich Fritz-Schlunder1198760times 10minus5

(mol gminus1)119887

(Lmolminus1) 11987721205942 119870F

(mol1minus1119899 L1119899 gminus1) 1119899 11987721205942 119902FS

(mol gminus1)119870FS

(Lmolminus1) 120572 11987721205942

3397 2480 0996 0005 2160 0326 0949 0062 2504 3385 0997 0996 0005

40

35

30

25

20

15

10

05

0045403530252015100500

pH 45

Temperature 30∘CEquilibrium time 90min

Adsorbent dose 2gL

Ce times 10minus5 (molL)

qetimes10

minus5

(mol

g)

FreundlichLangmuirFritz-Schlunder

Figure 8 Isotherm modeling for the EY adsorption onto P(Py-co-An)-TiO

2NCC

found to be much higher as compared to the conjugatedpolymer-grafted sawdust [30]

Freundlich isotherm equation can be applied to nonidealsorption on heterogeneous surfaces as well as to multilayersorption The value of Freundlich exponent 1119899 (0326) isin the range of 0 to 1 indicating a favorable adsorptionFritz-Schlunder isotherm model [31] is a widely acceptedisotherm model in which Fritz and Schlunder the equationsof Langmuir and Freundlich were developed empiricallyTheisotherm plots and the isotherm parameters are representedin Figure 8 and Table 2 respectively

As suggested by Figure 8 and Table 2 the equilibriumsorption data were best presented by Fritz-Schlunder iso-therm According to 1198772 and 1205942 values the adsorption iso-therm data follow the order Fritz-Schlunder gt Langmuir gtFreundlich

34 Photocatalytic Studies

341 Photocatalytic Degradation of EY and Its MechanismThephotocatalytic activities of P(Py-co-An)-TiO

2NCCwere

evaluated by the degradation of EY in an aqueous solu-tion under sunlight irradiation No degradation of EY was

0 20 40 60 80 100 120 140 160 180 200

Time (min)

08

10

12

14

16

18

20

ln(C

0C

)

Figure 9 Kinetic data for the photodegradation of EY onto P(Py-co-An)-TiO

2NCC

observed in the absence of a photocatalyst under visible lightillumination It was observed that photocatalytic degradationof EY increases with increase in irradiation time and 923 ofthe dye was degraded within 90min Photocatalytic degrada-tion was found to follow first-order rate equation for lowerconcentrations as follows

ln(1198620

119862

) = 119896119905 (7)

where 119862 is the concentration of the dye at time 119905 (molL)119905 is the illumination time in minutes 119896 is the reaction rateconstant (minminus1) and 119862

0is the concentration of the dye

before irradiation (molL) Figure 9 shows the relationshipbetween ln(119862119862

0) of EY and photodegradation time in the

presence of P(Py-co-An)-TiO2NCC for 90min under visible

light irradiationTheplot of ln(1198620119862) versus time represents a

straight line the slope of which upon linear regression equalsthe apparent first-order rate constant ldquo119896rdquo and was calculatedto be 000575minminus1 in the present study

342Mechanism of Photocatalysis TiO2particles can absorb

UV light from the sunlight to create electrons (eminus) in the con-duction band and holes (h+) in the valence band respectivelyIf the electrons and holes cannot be captured in time theywillrecombine with each other within a few nanoseconds whichwill reduce the photocatalytic efficiency of TiO

2 However

due to the existence of the interface between polymer andTiO2 separated electrons and holes have little possibility

to recombine again in the case of composites This ensures


higher charge separation efficiency andbetter photooxidationcapacity for the nanocomposite In addition the conjugatedpolymer can absorb the visible light and produces an electron(eminus) that transfers to the conduction band of TiO

2[32

33] and then to an adsorbed electron acceptor like dyeyielding oxygen radicals to degrade pollutants into mineralend products [34]

Thus the heterogeneous photocatalytic degradation of anazo compound can be summarized by the following reactions[35]

P (PPy-co-An) TiO2+ h] (solar light)

997888rarr P (PPy-co-An) TiO2

++ eCBminus

(i)

eCBminus+O2997888rarr TiO

2+O2

∙minus(ii)

P (PPy-co-An) TiO2

+

997888rarr P (PPy-co-An) TiO2+ hVB

+

(iii)

hVB++H2O 997888rarr TiO

2+H+ +OHminus (iv)

hVB++OHminus 997888rarr TiO

2+OH∙ (v)

O2

∙minus+H+ 997888rarr HO

2

∙(vi)

Dye +OH∙ 997888rarr Degradation products (vii)

Dye + hVB+997888rarr Oxidation products (viii)

Dye + eCBminus997888rarr Reduction products (ix)

Several authors make use of these types of conjugatedpolymers in the photodegradation of dye under visible lightThe conjugated polymers (CPs) with extended p-conjugatedelectron systems showed the relatively high photoelectricconversion efficiency and charge transfer due to their highabsorption coefficients in the visible part of the spectrumhigh mobility of charge carriers and good stability [36]pH adjustments using acid (H+) or alkali (OHminus) duringadsorption processes may increase the photocatalytic reac-tion rate in accordance with (v) and (vi) According toprevious literature the hydroxyl radical will oxidize eosinyellow to its leuco form which may ultimately degradeto environmentally benign products such as water carbondioxide and inorganic salts like bromides It was confirmedthat OH∙ radical participates as an active oxidizing speciesin the degradation of eosin yellow as the rate of degradationwas appreciably reduced in presence of hydroxyl radicalscavenger [37]

343 Photorecylability of P(Py-co-An)-TiO2NCC To exam-ine the photocatalytic stability adsorption of EY onto P(Py-co-An)-TiO

2NCC hydrogel was carried out at optimum

conditions and the adsorbed dye material was exposed tosunlight for degradation This process was repeated for fourcycles and the results obtained were depicted in Figure 10 Itcan be found that the adsorption capacity and photodegra-dation efficiency of EY slightly decrease with the recyclingruns up to four successive cycles The above results indicate

1 2 3 4

Photocatalytic degradationAdsorption

Number of cycles

Adso

rptio

n-de

grad

atio

n (

)

0

20

40

60

80

100

120

Figure 10 Adsorption-photocatalytic degradation cycle of EY onP(Py-co-An)-TiO

2NCC

that P(Py-co-An)-TiO2NCC shows excellent photocatalytic

stability

4 Conclusions

Eosin yellow (EY) is a carcinogenic dye and its exposuremay cause adverse effects Here we prepared a conductiveconjugated polymersemiconductor system poly(pyrrole-co-aniline)-coated TiO

2nanocellulose composite (P(Py-co-

An)-TiO2NCC) for the removal of EY from aqueous solu-

tions The samples under preparation stage were charac-terized by SEM XRD and FTIR analyses The systematicadsorption cum photocatalytic studies were carried out toexplore the optimumconditions for the dye removal Adsorp-tion of dye was highly dependent on pH and 917 of thedye was adsorbed at pH of 45 within 90min An adsorbentdose of 35 gL was needed for the complete adsorption of EYfrom aqueous solutions Adsorption follows both Langmuirand Fritz-Schlunder isotherm models and pseudo-second-order kinetics suggesting that chemisorption may be themechanism behind the adsorption process Photocatalyticdegradation of EY under sunlight produced reliable resultsP(Py-co-An)-TiO

2NCC shows excellent photocatalytic sta-

bility and recyclability Thus the present investigation showsthat the photocatalyst P(Py-co-An)-TiO

2NCC is a valuable

material for the adsorption and photocatalytic degradationof EY dye from aqueous solutions and can be developed as asupport for the removal of EY dye from industrial effluents

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper


Acknowledgment

The authors would like to thank the University GrantsCommission Government of India New Delhi for finan-cially supporting this research under Major Research Project(MRP) F no 37-4252009 (S R Rejeena)

References

[1] G M Walker L Hansen J-A Hanna and S J Allen ldquoKineticsof a reactive dye adsorption onto dolomitic sorbentsrdquo WaterResearch vol 37 no 9 pp 2081ndash2089 2003

[2] Y-Y Xu M Zhou H-J Geng et al ldquoA simplified method forsynthesis of Fe

3O4PAA nanoparticles and its application for

the removal of basic dyesrdquo Applied Surface Science vol 258 no8 pp 3897ndash3902 2012

[3] B Y Shi G H Li D S Wang C H Feng and H X TangldquoRemoval of direct dyes by coagulation the performance ofpreformed polymeric aluminum speciesrdquo Journal of HazardousMaterials vol 143 no 1-2 pp 567ndash574 2007

[4] R Ansari M S Tehrani and E Alizadeh ldquoApplication ofpoly(3-methyl thiophene)-saw dust nanocomposite for removalof anionic carmoisine dye from aqueous solutionsrdquo Journal ofAdvanced Scientific Research vol 3 pp 86ndash92 2012

[5] F Al-Momani E Touraud J R Degorce-Dumas J Roussy andO Thomas ldquoBiodegradability enhancement of textile dyes andtextile wastewater by VUV photolysisrdquo Journal of Photochem-istry and Photobiology A Chemistry vol 153 no 1ndash3 pp 191ndash1972002

[6] S Banerjee J Gopal P Muraleedharan A K Tyagi and B RajldquoPhysics and chemistry of photocatalytic titaniumdioxide visu-alization of bactericidal activity using atomic forcemicroscopyrdquoCurrent Science vol 90 no 10 pp 1378ndash1383 2006

[7] F Deng Y Li X Luo L Yang and X Tu ldquoPreparationof conductive polypyrroleTiO

2nanocomposite via surface

molecular imprinting technique and its photocatalytic activityunder simulated solar light irradiationrdquoColloids and Surfaces APhysicochemical and Engineering Aspects vol 395 pp 183ndash1892012

[8] M A Tariq M Faisal M Muneer and D BahnemannldquoPhotochemical reactions of a few selected pesticide derivativesand other priority organic pollutants in aqueous suspensions oftitanium dioxiderdquo Journal of Molecular Catalysis A Chemicalvol 265 no 1-2 pp 231ndash236 2007

[9] Y Yang H Zhang P Wang Q Zheng and J Li ldquoThe influenceof nano-sized TiO

2fillers on the morphologies and properties

of PSF UF membranerdquo Journal of Membrane Science vol 288no 1-2 pp 231ndash238 2007

[10] I A Shkrob M C Sauer Jr and D Gosztola ldquoEfficient rapidphotooxidation of chemisorbed polyhydroxyl alcohols andcarbohydrates by TiO

2nanoparticles in an aqueous solutionrdquo

The Journal of Physical Chemistry B vol 108 no 33 pp 12512ndash12517 2004

[11] S Kamel ldquoNanotechnology and its applications in lignocellu-losic composites a mini reviewrdquo eXPRESS Polymer Letters vol1 no 9 pp 546ndash575 2007

[12] C Lai G R Li Y Y Dou and X P Gao ldquoMesoporouspolyaniline or polypyrroleanatase TiO

2nanocomposite as

anode materials for lithium-ion batteriesrdquo Electrochimica Actavol 55 no 15 pp 4567ndash4572 2010

[13] J-D Kwon P-H Kim J-H Keum and J S Kim ldquoPolypyr-roletitania hybrids synthetic variation and test for the photo-voltaicmaterialsrdquo Solar EnergyMaterials and Solar Cells vol 83no 2-3 pp 311ndash321 2004

[14] H-C Liang and X-Z Li ldquoVisible-induced photocatalytic reac-tivity of polymer-sensitized titania nanotube filmsrdquo AppliedCatalysis B Environmental vol 86 no 1-2 pp 8ndash17 2009

[15] D Shao J Hu C Chen G Sheng X Ren and X WangldquoPolyaniline multiwalled carbon nanotube magnetic compositeprepared by plasma-induced graft technique and its applicationfor removal of aniline and phenolrdquo The Journal of PhysicalChemistry C vol 114 no 49 pp 21524ndash21530 2010

[16] G Chakraborty K Gupta A K Meikap R Babu and W JBlau ldquoSynthesis electrical and magnetotransport properties ofpolypyrrole-MWCNT nanocompositerdquo Solid State Communi-cations vol 152 no 1 pp 13ndash18 2012

[17] T S Anirudhan and S R Rejeena ldquoAdsorption and hydrolyticactivity of trypsin on a carboxylate-functionalized cationexchanger prepared from nanocelluloserdquo Journal of Colloid andInterface Science vol 381 no 1 pp 125ndash136 2012

[18] A Dolatshahi-Pirouz K Rechendorff M B Hovgaard MFoss J Chevallier and F Besenbacher ldquoBovine serum albuminadsorption on nano-rough platinum surfaces studied by QCM-Drdquo Colloids and Surfaces B Biointerfaces vol 66 no 1 pp 53ndash59 2008

[19] A Alemdar and M Sain ldquoIsolation and characterization ofnanofibers from agricultural residuesmdashwheat straw and soyhullsrdquo Bioresource Technology vol 99 no 6 pp 1664ndash16712008

[20] P Scherrer ldquoBestimmung der Grosse und der inneren Strukturvon Kolloidteilchen mittels Rontgenstrahlenrdquo Nachrichten vonder Gesellschaft derWissenschaften zuGottingen vol 26 pp 98ndash100 1918

[21] H-J Lee T-J Chung H-J Kwon H-J Kim and W T Y TzeldquoFabrication and evaluation of bacterial cellulose-polyanilinecomposites by interfacial polymerizationrdquo Cellulose vol 19 no4 pp 1251ndash1258 2012

[22] H S Barud R M N Assuncao M A U Martines et alldquoBacterial cellulose-silica organic-inorganic hybridsrdquo Journal ofSol-Gel Science and Technology vol 46 no 3 pp 363ndash367 2008

[23] L M Daniel R L Frost and H Y Zhu ldquoSynthesis and char-acterisation of clay-supported titania photocatalystsrdquo Journal ofColloid and Interface Science vol 316 no 1 pp 72ndash79 2007

[24] A Kapil M Taunk and S Chand ldquoPreparation and chargetransport studies of chemically synthesized polyanilinerdquo Journalof Materials Science Materials in Electronics vol 21 no 4 pp399ndash404 2010

[25] A Gok B Sari and M Talu ldquoSynthesis and characterization ofconducting substituted polyanilinesrdquo Synthetic Metals vol 142no 1ndash3 pp 41ndash48 2004

[26] R Ansari A Mohammad-Khah and Z Mosayebzadeh ldquoAppli-cation of unripe grape juice waste as an efficient low costbiosorbent for dye removalrdquo Annals of Biological Research vol2 pp 323ndash328 2011

[27] R Ansari andM B Keivani ldquopolyaniline conducting electroac-tive polymers thermal and environmental stability studiesrdquo E-Journal of Chemistry vol 3 no 4 pp 202ndash217 2006

[28] I Langmuir ldquoThe adsorption of gases on plane surfaces of glassmica and platinumrdquo Journal of the American Chemical Societyvol 40 no 9 pp 1361ndash1403 1918


[29] V Vimonses S Lei B Jin C W K Chow and C SaintldquoAdsorption of congo red by three Australian kaolinsrdquo AppliedClay Science vol 43 no 3-4 pp 465ndash472 2009

[30] R Ansari and Z Mosayebzadeh ldquoRemoval of Eosin Y ananionic dye from aqueous solutions using conducting elec-troactive polymersrdquo Iranian Polymer Journal vol 19 no 7 pp541ndash551 2010

[31] W Fritz and E-U Schluender ldquoSimultaneous adsorption equi-libria of organic solutes in dilute aqueous solutions on activatedcarbonrdquo Chemical Engineering Science vol 29 no 5 pp 1279ndash1282 1974

[32] S Zhu W Wei X Chen M Jiang and Z Zhou ldquoHybridstructure of polyanilineZnO nanograss and its applicationin dye-sensitized solar cell with performance improvementrdquoJournal of Solid State Chemistry vol 190 pp 174ndash179 2012

[33] R Jamal Y Osman A Rahman A Ali Y Zhang and TAbdiryim ldquoSolid-state synthesis and photocatalytic activity ofpolyterthiophene derivativesTiO

2nanocompositesrdquoMaterials

vol 7 no 5 pp 3786ndash3801 2014[34] X Huang G Wang M Yang W Guo and H Gao ldquoSynthesis

of polyaniline-modified Fe3O4SiO

2TiO2composite micro-

spheres and their photocatalytic applicationrdquoMaterials Lettersvol 65 no 19-20 pp 2887ndash2890 2011

[35] J Cunningham G Al-Sayyed and S Srijaranai Aquatic andSurface Photochemistry Lewis Publisher CRC Press 1994

[36] S Min F Wang and Y Han ldquoAn investigation on synthesis andphotocatalytic activity of polyaniline sensitized nanocrystallineTiO2compositesrdquo Journal of Materials Science vol 42 no 24

pp 9966ndash9972 2007[37] S Gupta R Diptisoni and S Benjamin ldquoUse of barium chro-

mate in photocatalytic degradation of eosin yellowrdquo ChemicalScience Transactions vol 4 pp 851ndash857 2015

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



CeramicsJournal of


CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


for TiO2photocatalyst since they have the advantages such

as low cost and easy separation from reaction solutionCellulose obtained from wood pulp and cotton is such amaterial used for this purpose due to its low cost and easyavailability Cellulose has been explored as a substrate forcomposite materials because of the presence of functionalgroups that may be employed in various activation processesAdditionally it was suggested that the holesrsquo scavengingability increases with the increasing number and spatialdistribution of the hydroxyl groups in the polyhydroxylcompounds [10] When cellulose is converting to theirnanocrystals the holesrsquo scavenging ability increases due to thelarge number of hydroxyl groups exposed to the surface Thenanocellulose ismechanically strong and produced a strengthof 25 that of carbon nanotubes [11]

Conducting polymers such as polypyrrole polyanilineand polythiophene have functioned as dopants which shiftthe border of the TiO

2particles to longer wavelengths

thereby improving the optical absorption in the visibleregion These hybrid conducting polymerTiO

2composites

exhibit excellent properties unlike those of the individualmaterials such as controlled conductivity and thermal ormechanical stability and these properties have made thempotentially applicable as anode materials for lithium-ionbatteries [12] anode electrodes for dye solar cells [13] orphotocatalytic materials [14]The conjugated polymers couldbe separated from the aqueous phase by using simple gravitysettling and could be recycled easily The conjugated poly-mers have an extended conjugation system and behave likesemiconducting materials with low charge carrier mobilityPolyaniline (PAn) has been deposited on various materialsto perform desired applications [15] Polypyrrole (PPy) hasa potential application in the field of composite materials dueto their appreciable environmental stability higher electricalconductivity easier synthesis and solubility in differentsolvents [16]

As we know eosin yellow (EY) is widely used for stainingpurposes however it is listed as a carcinogen The presentwork is aimed at wiping out the textile dye EY from theenvironment for the well-being of the organisms In thepresent work a novel polymer composite poly(pyrrole-co-aniline)-coated TiO

2nanocellulose composite [P(Py-co-

An)-TiO2NCC] was prepared for the adsorptive removal

of EY from aqueous solutions followed by photocatalyticdegradation under sunlight For the preparation of thispolymeric hydrogel glutaraldehyde the agent widely used forindustrial water treatment and a preservative was selected asa crosslinker

2 Materials and Methods

21 Materials Sawdust of Mangifera indica was a kind giftfrom Local Saw mill Trivandrum Titanium(IV) isopropox-ide (97) eosin yellow (EY) pyrrole (Py) aniline (An) andglutaraldehyde were purchased from SigmaAldrich H

2S2O4

NaOH HNO3 FeCl

3 H2O2 ethanol HCl and ammonium

persulfate (APS) were received from E Merck India All thechemicals were used without further purification Deionized

water was used in preparing the aqueous stock solutions forthe adsorption-photocatalytic experiments

22 Preparation of P(Py-co-An)-TiO2NCC

221 Extraction of Nanocellulose (NC) from Sawdust Cellu-lose has been extracted from sawdust and was converted tonanocrystals following the procedure reported earlier [17]Briefly sawdust was pretreated with 10 H

2SO4solution

(120∘C 10min) and centrifuged to remove rich pentosanssolution Delignification was achieved by the subsequenttreatment with 1 NaOH (100∘C 1 h) The obtained brownmass upon bleaching with 5 H

2O2(80∘C 1 h) yielded

white cellulose About 5 g of cellulose was dispersed in250mL distilled water under magnetic stirring (20min)140mL 98 sulfuric acid was dropped to the homogenizedmixture without causing heating After complete additionthe mixture was heated at 50∘C for 2 h The hot mixture wasdiluted ten times with ice cooled distilled waterThe obtainedwhite colloidwas centrifuged washedmany timeswithwaterand freeze-dried

222 Preparation of TiO2NC Composite (TiO2NCC) NC(02 g) HNO

3(5mL 01M) and absolute ethanol (100mL)

were mixed with each other and the mixture was ultrasoni-cally dispersed for 1 h After dispersion 1mL of titanium(IV)isopropoxide was added to this mixture slowly with a con-stant pressure funnel under magnetic stirring The reactiontemperature was kept at 40∘C for 4 h Finally the suspensionwas diluted fivefold with water centrifuged and then washedwith water repeatedly The precipitate was dialyzed againstdeionized water for 2 days and then freeze-dried

223 Preparation of P(Py-co-An)-TiO2NCC P(Py-co-An)-TiO2NCC was synthesized by chemical oxidation of its

respective monomers Py and An by keeping their molarratios constant at 1 1 The aqueous solution of TiO

2NCC

(240mg in 100mL) was mixed with a solution of pyrrole(3mL) aniline (3mL) and HCl (37 016mL) for 30minwhere after APS (046 g) and of FeCl

3(80 g) was added

respectively in the solution for polymerization initiationand stirred for 3 h The obtained product with a layer ofpoly(pyrrole-co-aniline) was filtered washed with ethanoland dried at 50∘CThe dried product designated as P(Py-co-An)-TiO

2NCC was sieved to get an average particle size of

0096mmand used for adsorption followed by photocatalyticexperiments

23 Characterization of P(Py-co-An)-TiO2NCC Surfacemorphology of the adsorbents was investigated by SEMmicrographs recorded with a JEOL JSM 6390 LA scanningelectron microscope The Brunauer-Emmett-Teller (BET)surface area was determined using a model Q7S surfacearea analyzer (Quantasorb USA) The XRD patterns wererecorded using XrsquoPert Pro X-ray diffractometer Patternswere recorded in the 2120579 range of 10ndash70 at a scan rate of2 countss The FTIR spectra of adsorbents were recorded onKBr pellets with FTIR spectrophotometer in the wavelength








1198620

times 100

119902119890= (1198620minus 119862119890) times

119881

119898

(1)

where 1198620and 119862









1198620

times 100 (2)

where 1198620and 119862






2NCC was prepared













2particles to be






2NCCThe




2


2in






(d)(c)

(b)(a)


2NCC

234

256

382

482

546

634

161

101

220

342

159

226

339

159

54222

8

188

671

167

253

382

457

476

520

642

119

20 30 40 50 60 7010

2120579 (deg)

CelluloseNC



2NCC


tr

ansm

ittan

ce (a

u)

3318

11121642

539

1540

1035

1745

1643

1058


3441 2922

3417

1033

1636

2899

2356

1697

1457

5493753 18

68

1041

5001000150020002500300035004000

CelluloseNC



An)-TiO2NCC


2)










Adso

rptio

n (

)

Adsorbent dose (gL)

100

80

60

40

20

011109876543210




2NCC


2NCC 35 gL





2NCC was strongly










(mol gminus1)



minus5

(mol gminus1) 11987721205942 119896

2


minus611987721205942

1 0458 0270 0447 0974 00003 1234 0461 0262 0995 7 times 10minus5

5 2202 0279 2157 0977 0007 0003 2218 0015 0996 00014

Temperature 30∘C


Adsorbent dose 2gL

3 4 5 6 7 8 92

pH

65

70

75

80

85

90

95

100

105

Adso

rptio

n (

)





minus1198961119905)


1198962119902119890

2119905

1 + 1199051198962119902119890

(3)

where 119902119890and 119902








ℎ0= 1198962119902119890

2 (4)



2were




119902119890=

1198760119887119862119890

1 + 119887119862119890

119902119890= 119870F119862119890

1119899

119902119890=

119902FS119870FS1198621198901 + 119902FS119862119890

120572

(5)


NH

NH

NH

n

n

C-

O

O O

BrBr

BrBr

HN



minusO

Ominus

++



Time (min)240220200180160140120100806040200

00

05

10

15

20

25

30

35

qetimes10

minus5

(mol

g)


Experimental


Adsorbent dose 2gL


2NCC






119877L =1

1 + 1198871198620

(6)





2NCC


2NCC towards EY was




(mol gminus1)119887

(Lmolminus1) 11987721205942 119870F



(Lmolminus1) 120572 11987721205942

3397 2480 0996 0005 2160 0326 0949 0062 2504 3385 0997 0996 0005

40

35

30

25

20

15

10

05

0045403530252015100500

pH 45


Adsorbent dose 2gL


qetimes10

minus5

(mol

g)



2NCC






2NCCwere


0 20 40 60 80 100 120 140 160 180 200

Time (min)

08

10

12

14

16

18

20

ln(C

0C

)


2NCC


ln(1198620

119862

) = 119896119905 (7)










2 However





2[32





++ eCBminus

(i)


2+O2

∙minus(ii)

P (PPy-co-An) TiO2

+


+

(iii)


2+H+ +OHminus (iv)


2+OH∙ (v)

O2


2

∙(vi)








1 2 3 4


Number of cycles

Adso

rptio

n-de

grad

atio

n (

)

0

20

40

60

80

100

120


2NCC


stability

4 Conclusions







2NCC is a valuable





Acknowledgment


References





















2nanocomposite as








































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials










1198620

times 100

119902119890= (1198620minus 119862119890) times

119881

119898

(1)

where 1198620and 119862









1198620

times 100 (2)

where 1198620and 119862






2NCC was prepared













2particles to be






2NCCThe




2


2in






(d)(c)

(b)(a)


2NCC

234

256

382

482

546

634

161

101

220

342

159

226

339

159

54222

8

188

671

167

253

382

457

476

520

642

119

20 30 40 50 60 7010

2120579 (deg)

CelluloseNC



2NCC


tr

ansm

ittan

ce (a

u)

3318

11121642

539

1540

1035

1745

1643

1058


3441 2922

3417

1033

1636

2899

2356

1697

1457

5493753 18

68

1041

5001000150020002500300035004000

CelluloseNC



An)-TiO2NCC


2)










Adso

rptio

n (

)

Adsorbent dose (gL)

100

80

60

40

20

011109876543210




2NCC


2NCC 35 gL





2NCC was strongly










(mol gminus1)



minus5

(mol gminus1) 11987721205942 119896

2


minus611987721205942

1 0458 0270 0447 0974 00003 1234 0461 0262 0995 7 times 10minus5

5 2202 0279 2157 0977 0007 0003 2218 0015 0996 00014

Temperature 30∘C


Adsorbent dose 2gL

3 4 5 6 7 8 92

pH

65

70

75

80

85

90

95

100

105

Adso

rptio

n (

)





minus1198961119905)


1198962119902119890

2119905

1 + 1199051198962119902119890

(3)

where 119902119890and 119902








ℎ0= 1198962119902119890

2 (4)



2were




119902119890=

1198760119887119862119890

1 + 119887119862119890

119902119890= 119870F119862119890

1119899

119902119890=

119902FS119870FS1198621198901 + 119902FS119862119890

120572

(5)


NH

NH

NH

n

n

C-

O

O O

BrBr

BrBr

HN



minusO

Ominus

++



Time (min)240220200180160140120100806040200

00

05

10

15

20

25

30

35

qetimes10

minus5

(mol

g)


Experimental


Adsorbent dose 2gL


2NCC






119877L =1

1 + 1198871198620

(6)





2NCC


2NCC towards EY was




(mol gminus1)119887

(Lmolminus1) 11987721205942 119870F



(Lmolminus1) 120572 11987721205942

3397 2480 0996 0005 2160 0326 0949 0062 2504 3385 0997 0996 0005

40

35

30

25

20

15

10

05

0045403530252015100500

pH 45


Adsorbent dose 2gL


qetimes10

minus5

(mol

g)



2NCC






2NCCwere


0 20 40 60 80 100 120 140 160 180 200

Time (min)

08

10

12

14

16

18

20

ln(C

0C

)


2NCC


ln(1198620

119862

) = 119896119905 (7)










2 However





2[32





++ eCBminus

(i)


2+O2

∙minus(ii)

P (PPy-co-An) TiO2

+


+

(iii)


2+H+ +OHminus (iv)


2+OH∙ (v)

O2


2

∙(vi)








1 2 3 4


Number of cycles

Adso

rptio

n-de

grad

atio

n (

)

0

20

40

60

80

100

120


2NCC


stability

4 Conclusions







2NCC is a valuable





Acknowledgment


References





















2nanocomposite as








































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




(d)(c)

(b)(a)


2NCC

234

256

382

482

546

634

161

101

220

342

159

226

339

159

54222

8

188

671

167

253

382

457

476

520

642

119

20 30 40 50 60 7010

2120579 (deg)

CelluloseNC



2NCC


tr

ansm

ittan

ce (a

u)

3318

11121642

539

1540

1035

1745

1643

1058


3441 2922

3417

1033

1636

2899

2356

1697

1457

5493753 18

68

1041

5001000150020002500300035004000

CelluloseNC



An)-TiO2NCC


2)










Adso

rptio

n (

)

Adsorbent dose (gL)

100

80

60

40

20

011109876543210




2NCC


2NCC 35 gL





2NCC was strongly










(mol gminus1)



minus5

(mol gminus1) 11987721205942 119896

2


minus611987721205942

1 0458 0270 0447 0974 00003 1234 0461 0262 0995 7 times 10minus5

5 2202 0279 2157 0977 0007 0003 2218 0015 0996 00014

Temperature 30∘C


Adsorbent dose 2gL

3 4 5 6 7 8 92

pH

65

70

75

80

85

90

95

100

105

Adso

rptio

n (

)





minus1198961119905)


1198962119902119890

2119905

1 + 1199051198962119902119890

(3)

where 119902119890and 119902








ℎ0= 1198962119902119890

2 (4)



2were




119902119890=

1198760119887119862119890

1 + 119887119862119890

119902119890= 119870F119862119890

1119899

119902119890=

119902FS119870FS1198621198901 + 119902FS119862119890

120572

(5)


NH

NH

NH

n

n

C-

O

O O

BrBr

BrBr

HN



minusO

Ominus

++



Time (min)240220200180160140120100806040200

00

05

10

15

20

25

30

35

qetimes10

minus5

(mol

g)


Experimental


Adsorbent dose 2gL


2NCC






119877L =1

1 + 1198871198620

(6)





2NCC


2NCC towards EY was




(mol gminus1)119887

(Lmolminus1) 11987721205942 119870F



(Lmolminus1) 120572 11987721205942

3397 2480 0996 0005 2160 0326 0949 0062 2504 3385 0997 0996 0005

40

35

30

25

20

15

10

05

0045403530252015100500

pH 45


Adsorbent dose 2gL


qetimes10

minus5

(mol

g)



2NCC






2NCCwere


0 20 40 60 80 100 120 140 160 180 200

Time (min)

08

10

12

14

16

18

20

ln(C

0C

)


2NCC


ln(1198620

119862

) = 119896119905 (7)










2 However





2[32





++ eCBminus

(i)


2+O2

∙minus(ii)

P (PPy-co-An) TiO2

+


+

(iii)


2+H+ +OHminus (iv)


2+OH∙ (v)

O2


2

∙(vi)








1 2 3 4


Number of cycles

Adso

rptio

n-de

grad

atio

n (

)

0

20

40

60

80

100

120


2NCC


stability

4 Conclusions







2NCC is a valuable





Acknowledgment


References





















2nanocomposite as








































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




tr

ansm

ittan

ce (a

u)

3318

11121642

539

1540

1035

1745

1643

1058


3441 2922

3417

1033

1636

2899

2356

1697

1457

5493753 18

68

1041

5001000150020002500300035004000

CelluloseNC



An)-TiO2NCC


2)










Adso

rptio

n (

)

Adsorbent dose (gL)

100

80

60

40

20

011109876543210




2NCC


2NCC 35 gL





2NCC was strongly










(mol gminus1)



minus5

(mol gminus1) 11987721205942 119896

2


minus611987721205942

1 0458 0270 0447 0974 00003 1234 0461 0262 0995 7 times 10minus5

5 2202 0279 2157 0977 0007 0003 2218 0015 0996 00014

Temperature 30∘C


Adsorbent dose 2gL

3 4 5 6 7 8 92

pH

65

70

75

80

85

90

95

100

105

Adso

rptio

n (

)





minus1198961119905)


1198962119902119890

2119905

1 + 1199051198962119902119890

(3)

where 119902119890and 119902








ℎ0= 1198962119902119890

2 (4)



2were




119902119890=

1198760119887119862119890

1 + 119887119862119890

119902119890= 119870F119862119890

1119899

119902119890=

119902FS119870FS1198621198901 + 119902FS119862119890

120572

(5)


NH

NH

NH

n

n

C-

O

O O

BrBr

BrBr

HN



minusO

Ominus

++



Time (min)240220200180160140120100806040200

00

05

10

15

20

25

30

35

qetimes10

minus5

(mol

g)


Experimental


Adsorbent dose 2gL


2NCC






119877L =1

1 + 1198871198620

(6)





2NCC


2NCC towards EY was




(mol gminus1)119887

(Lmolminus1) 11987721205942 119870F



(Lmolminus1) 120572 11987721205942

3397 2480 0996 0005 2160 0326 0949 0062 2504 3385 0997 0996 0005

40

35

30

25

20

15

10

05

0045403530252015100500

pH 45


Adsorbent dose 2gL


qetimes10

minus5

(mol

g)



2NCC






2NCCwere


0 20 40 60 80 100 120 140 160 180 200

Time (min)

08

10

12

14

16

18

20

ln(C

0C

)


2NCC


ln(1198620

119862

) = 119896119905 (7)










2 However





2[32





++ eCBminus

(i)


2+O2

∙minus(ii)

P (PPy-co-An) TiO2

+


+

(iii)


2+H+ +OHminus (iv)


2+OH∙ (v)

O2


2

∙(vi)








1 2 3 4


Number of cycles

Adso

rptio

n-de

grad

atio

n (

)

0

20

40

60

80

100

120


2NCC


stability

4 Conclusions







2NCC is a valuable





Acknowledgment


References





















2nanocomposite as








































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







(mol gminus1)



minus5

(mol gminus1) 11987721205942 119896

2


minus611987721205942

1 0458 0270 0447 0974 00003 1234 0461 0262 0995 7 times 10minus5

5 2202 0279 2157 0977 0007 0003 2218 0015 0996 00014

Temperature 30∘C


Adsorbent dose 2gL

3 4 5 6 7 8 92

pH

65

70

75

80

85

90

95

100

105

Adso

rptio

n (

)





minus1198961119905)


1198962119902119890

2119905

1 + 1199051198962119902119890

(3)

where 119902119890and 119902








ℎ0= 1198962119902119890

2 (4)



2were




119902119890=

1198760119887119862119890

1 + 119887119862119890

119902119890= 119870F119862119890

1119899

119902119890=

119902FS119870FS1198621198901 + 119902FS119862119890

120572

(5)


NH

NH

NH

n

n

C-

O

O O

BrBr

BrBr

HN



minusO

Ominus

++



Time (min)240220200180160140120100806040200

00

05

10

15

20

25

30

35

qetimes10

minus5

(mol

g)


Experimental


Adsorbent dose 2gL


2NCC






119877L =1

1 + 1198871198620

(6)





2NCC


2NCC towards EY was




(mol gminus1)119887

(Lmolminus1) 11987721205942 119870F



(Lmolminus1) 120572 11987721205942

3397 2480 0996 0005 2160 0326 0949 0062 2504 3385 0997 0996 0005

40

35

30

25

20

15

10

05

0045403530252015100500

pH 45


Adsorbent dose 2gL


qetimes10

minus5

(mol

g)



2NCC






2NCCwere


0 20 40 60 80 100 120 140 160 180 200

Time (min)

08

10

12

14

16

18

20

ln(C

0C

)


2NCC


ln(1198620

119862

) = 119896119905 (7)










2 However





2[32





++ eCBminus

(i)


2+O2

∙minus(ii)

P (PPy-co-An) TiO2

+


+

(iii)


2+H+ +OHminus (iv)


2+OH∙ (v)

O2


2

∙(vi)








1 2 3 4


Number of cycles

Adso

rptio

n-de

grad

atio

n (

)

0

20

40

60

80

100

120


2NCC


stability

4 Conclusions







2NCC is a valuable





Acknowledgment


References





















2nanocomposite as








































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




NH

NH

NH

n

n

C-

O

O O

BrBr

BrBr

HN



minusO

Ominus

++



Time (min)240220200180160140120100806040200

00

05

10

15

20

25

30

35

qetimes10

minus5

(mol

g)


Experimental


Adsorbent dose 2gL


2NCC






119877L =1

1 + 1198871198620

(6)





2NCC


2NCC towards EY was




(mol gminus1)119887

(Lmolminus1) 11987721205942 119870F



(Lmolminus1) 120572 11987721205942

3397 2480 0996 0005 2160 0326 0949 0062 2504 3385 0997 0996 0005

40

35

30

25

20

15

10

05

0045403530252015100500

pH 45


Adsorbent dose 2gL


qetimes10

minus5

(mol

g)



2NCC






2NCCwere


0 20 40 60 80 100 120 140 160 180 200

Time (min)

08

10

12

14

16

18

20

ln(C

0C

)


2NCC


ln(1198620

119862

) = 119896119905 (7)










2 However





2[32





++ eCBminus

(i)


2+O2

∙minus(ii)

P (PPy-co-An) TiO2

+


+

(iii)


2+H+ +OHminus (iv)


2+OH∙ (v)

O2


2

∙(vi)








1 2 3 4


Number of cycles

Adso

rptio

n-de

grad

atio

n (

)

0

20

40

60

80

100

120


2NCC


stability

4 Conclusions







2NCC is a valuable





Acknowledgment


References





















2nanocomposite as








































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






(mol gminus1)119887

(Lmolminus1) 11987721205942 119870F



(Lmolminus1) 120572 11987721205942

3397 2480 0996 0005 2160 0326 0949 0062 2504 3385 0997 0996 0005

40

35

30

25

20

15

10

05

0045403530252015100500

pH 45


Adsorbent dose 2gL


qetimes10

minus5

(mol

g)



2NCC






2NCCwere


0 20 40 60 80 100 120 140 160 180 200

Time (min)

08

10

12

14

16

18

20

ln(C

0C

)


2NCC


ln(1198620

119862

) = 119896119905 (7)










2 However





2[32





++ eCBminus

(i)


2+O2

∙minus(ii)

P (PPy-co-An) TiO2

+


+

(iii)


2+H+ +OHminus (iv)


2+OH∙ (v)

O2


2

∙(vi)








1 2 3 4


Number of cycles

Adso

rptio

n-de

grad

atio

n (

)

0

20

40

60

80

100

120


2NCC


stability

4 Conclusions







2NCC is a valuable





Acknowledgment


References





















2nanocomposite as








































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





2[32





++ eCBminus

(i)


2+O2

∙minus(ii)

P (PPy-co-An) TiO2

+


+

(iii)


2+H+ +OHminus (iv)


2+OH∙ (v)

O2


2

∙(vi)








1 2 3 4


Number of cycles

Adso

rptio

n-de

grad

atio

n (

)

0

20

40

60

80

100

120


2NCC


stability

4 Conclusions







2NCC is a valuable





Acknowledgment


References





















2nanocomposite as








































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




Acknowledgment


References





















2nanocomposite as








































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials

























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



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