Synthesis and Investigation of Antimicrobial Activity of O...

$: Synthesis and Investigation of Antimicrobial Activity of O ...downloads.hindawi.com/archive/2017/7056864.pdf(ICP-AES) on a Perkin-Elmer, Optima 5300DV. X-ray diffraction(XRD)ofCu2$
Research ArticleSynthesis and Investigation of Antimicrobial Activity ofCu2O NanoparticlesZeolite

Bui Duy Du1 Dang Van Phu2 Le Anh Quoc2 and Nguyen Quoc Hien2

1 Institute of Applied Material Science Vietnam Academy of Science and Technology 1 Mac Dinh Chi Street District 1Ho Chi Minh City Vietnam2Research and Development Center for Radiation Technology Vietnam Atomic Energy Institute 202A Street 11 Linh Xuan WardThu Duc District Ho Chi Minh City Vietnam

Correspondence should be addressed to Nguyen Quoc Hien hien7240238yahoocom

Received 13 September 2016 Revised 24 November 2016 Accepted 7 December 2016 Published 9 January 2017

Academic Editor Raphael Schneider

Copyright copy 2017 Bui Duy Du et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Cuprous oxide (Cu2O) nanoparticles in zeolite A were synthesized by two steps (i) ion-exchange of copper ions into the zeolite

and (ii) reduction of copper ions in cages of the zeolite by hydrazine hydrate in base medium The Cu2O nanoparticleszeolite

product was characterized by X-ray diffraction (XRD) transmission electron microscopy (TEM) and energy-dispersive X-rayspectroscopy (EDX) The particle size of Cu

2O nanoparticles was of 40 nm The antibacterial activity of the as-synthesized Cu

2O

nanoparticleszeolite against Escherichia coli was also investigated Cu2O NPszeolite product can be favorably produced on large

scale for water treatment and agricultural application as antimicrobial agent

1 Introduction

Metal nanoparticles (NPs) have attracted considerable atten-tion because of their unique properties such as catalytic mag-netic optical biological and electrical properties Amongmetal NPs Au and Ag NPs have been most extensivelystudied and applied due to their stability and suitability tohandle in air [1] Recently Cu NPs have been expected to bea good choice of the next-generation NPs mainly because oflow cost [2] In addition Cu oxide NPs namely cupric oxide(CuO) and cuprous oxide (Cu

2O) are among themost widely

used as antimicrobial agents for their high efficacy towardsa broad spectrum of microorganisms [2ndash4] There has beenalso considerable attention throughout the years for Cu

2O as

a candidate material for photovoltaics photocatalytic degra-dation of organic pollutants and decomposition of water intoO2andH

2under visible light and even as a negative electrode

material for lithium ion batteries [5ndash7] According to Wickand Tilley [8] Cu

2O is a promisingmaterial with the capacity

for low cost large-scale solar energy conversion due to theabundant nature of copper and oxygen suitable bandgap ofvisible light and effective low energy intensity fabricationprocess The antimicrobial activity of copper has long been

recognizedHowever relatively few studies have been focusedon the antimicrobial properties of Cu oxide NPs [4] Huanget al [3] reported that the inhibition efficiency of the 500ndash750mgkg CuONPs against tomato early blight A solaniwas707ndash807 it is better than that of the 50 carbendazimFurthermore the inhibition effect of the 500mgkg CuONPs on pepper root rot pathogen was significantly lowerthan that of the 75 chlorothalonil but higher than that ofthe 50 carbendazim However the CuO NPs showed noinhibitory effect on vegetable B cinerea pathogen Accordingto Ren et al [9] both octahedral and cubic Cu

2O crystals

could inhibit the growth of E coli efficiently and theirbactericidal activities become stronger with increased Cu

2O

concentration Up to 85 E coli are killed in the presenceof Cu

2O particles with concentration of 25120583mL Zeolite

A is microporous aluminosilicate material with small poresize and high absorptivity commonly used as a commercialadsorbent in gas purification and ion-exchange separation[10] Zeolite A is also used as catalyst as molecular sieve inthe production of laundry detergents in agriculture purposesfor the preparation of advanced materials and recently toproduce the nanocomposites [11] Synthesis of CuO NPswithin zeolite Y by reaction of Cu2+-exchanged zeolite with

HindawiJournal of NanoparticlesVolume 2017 Article ID 7056864 6 pageshttpsdoiorg10115520177056864

2 Journal of Nanoparticles

sodium hydroxide and calcification at 350∘C for 2 h wasstudied by Razavi and Loghman-Estarki [12] In the presentstudy Cu

2O NPs were synthesized within the zeolite A

framework using CuSO4as copper precursor and hydrazine

hydrate (N2H4sdotH2O) as reducing agent The antibacterial

activity of the obtained Cu2ONPszeolite against Escherichia

coli (E coli) was also investigated

2 Methods

21 Materials and Chemicals Analytical grade CuSO4sdot5H2O

NH4OH (25) and N

2H4sdotH2O (80) were products from

Merck and industrial grade sodium type of zeolite A withchemical formulation Na

2OsdotAl2O3 2SiO

2sdot45H2O was a

product from Shangdong Aluminium Corporation (SALCOChina) The Luria-Bertani (LB) medium for bacterial incu-bation was purchased from Himedia India The strain of Ecoli ATCC 6538 was provided by the University of MedicalPharmacy Ho Chi Minh City Distilled water was used in allexperiments

22 Exchange of Cu2+ Ions in Zeolite 1 kg of zeolite wassuspended into a glass beaker containing 15 L water ThenHNO

32N and water were added to zeolite suspension

mixture for neutralization to pH sim65 and for final volume ofabout 4 L 042 kg of CuSO

4sdot5H2O was dissolved in 500mL

water and then poured slowly into neutralized zeolite sus-pension mixture Stirring was carried out for 2 h at ambienttemperature for complete exchange of Cu2+ into zeoliteBefore adding hydrazine pH of the Cu2+zeolite mixture wasadjusted by ammonia water to sim75

23 Reduction of Cu2+ to Cu2O NPs in Zeolite A freshlyprepared 250mL hydrazine 20 (wv) solution was addeddropwise to the above Cu2+zeolite under stirring for 2 h atambient temperature Then reduction reaction was stoppedand let standing overnight for Cu

2O NPszeolite settling

down Finally Cu2O NPszeolite product was filtered off

using cotton fabric washed several times with water anddried in a forced air oven at 60∘C till to constant weight

24 Characterization of Cu2O NPsZeolite The content ofcopper in Cu

2O NPszeolite product was determined by

inductively coupled plasma-atomic emission spectroscopy(ICP-AES) on a Perkin-Elmer Optima 5300DV X-raydiffraction (XRD) of Cu

2O NPszeolite product was carried

out onD8Advance Bruker Germany and theCu2ONPs sizes

were measured using a transmission electron microscope(TEM JEM1010 JEOLTokyo Japan)Thepresence of copperin Cu

2O NPszeolite was also assessed by energy-dispersive

X-ray spectroscopy (EDX) on a JEOL 6610 LA

25 Antibacterial Activity of Cu2O NPsZeolite In vitro testof bactericidal activity of Cu2+zeolite and Cu

2O NPszeolite

against E coli was carried out following the procedure asdescribed in [13ndash15] Briefly the antibacterial activity of thematerials was tested by culture medium toxicity method

in Luria-Bertani medium The test material samples andcontrol were shaken in E coli suspension at 150 rpm at roomtemperature for 4 h After that the number of viable bacteriain eachmixture was determined by spread plate technique onLB agar plates The antibacterial efficiency (120578) was calculatedusing the equation 120578 () = (119873

119900minus 119873) times 100119873

119900 where 119873

119900

and119873 are the survival numbers of bacteria in the control andstudied samples respectively

3 Results and Discussion

31 Characterization of Cu2O NPsZeolite Figure 1 showedthe photograph of zeolite Cu2+zeolite and Cu

2O NPszeo-

lite It is clearly observed from Figure 1 that Cu2ONPszeolite

is reddish color The reaction of hydrazine used as reducingagent can be expressed by

N2H4+ 4OHminus 997888rarr N

2+ 4H2O + 4eminus (1)

Dimitrijevic et al reported that hydrazine hydrate has beenconsidered as a preferred reducing agent and used forindustrial scale production of silver powder for decades [16]According to Kuo and Huang [17] in base medium theformation of Cu

2O NPs can be described in the following

reactions

2Cu (OH)4

2minus +N2H4+ 2OHminus

997888rarr Cu2O +N

2+ 5H2O + 4OHminus

(2)

Cu2O + Cu

2O + Cu

2O + sdot sdot sdot 997888rarr Cu

2O nano (3)

TEM images of zeolite and Cu2O NPszeolite in Figure 2

indicated that the size of Cu2ONPs in the frameworks of the

zeolite was in the range from 5 to about 30 nm It can be alsosurprisingly observed in Figure 2 that beside the black dotssome parts of the morphology of Cu

2O NPs in zeolite were

almost as wormlike formThese Cu2ONPs seem to be linked

together within the intercages of zeolite structureThe XRD pattern of Cu

2O NPszeolite A in Figure 3

showed that diffraction peaks appeared at 2961∘ 3648∘4238∘ 6146∘ 7356∘ and 7752∘ corresponding to (110) (111)(200) (220) (311) and (222) planes of cuprite respectivelythat indicated the formation of Cu

2O nanocrystals (JCPDS

Card number 05-0667) [4 18] The average crystalline sizeof Cu

2O NPs determined by taking the full width at half

maximum (FWHM) of the most intense peak at 3648∘using Debye-Scherrerrsquos formula [18] was of about 40 nmThe crystalline size calculated from XRD patterns is usuallybigger than that from TEM images that also happened inour previous study [14] and in this study as well Therewas not any diffraction peak in XRD pattern in Figure 3assigned for CuO nanocrystal however low intensity peaksalso appeared at 4336∘ 5043∘ and 7425∘ that assigned forCu nanocrystals (JCPDSCard number 04-0836) [4 12]Thusduring reduction reactions a certain small amount of Cucould be formed in the following reaction

2Cu2+ +N2H4+ 4OHminus 997888rarr 2Cuo + N

2+ 4H2O (4)

Journal of Nanoparticles 3

(c)(b)(a)

Figure 1 Photograph of zeolite (a) Cu2+zeolite (b) and Cu2O NPszeolite (c)

(a) (b)

Figure 2 TEM images of zeolite A (a) and Cu2O NPszeolite A (b)

CuNPsZeoliteZeolite

Cou

nts

COD 9011604 Cu copper

Commander sample ID (coupled two thetatheta)Cu2O2961

∘

(110)Cu2O3648

∘

(111)

Cu2O4238

∘

(200)Cu

4336∘

(111) Cu5043

∘

(200)

Cu2O6146

∘

(220)Cu2O7356

∘

(311)

Cu7425

∘

(220)Cu2O7752

∘

(222)

COD 1010941 Cu2O cuprite

2120579 (∘)8070605040302010

Figure 3 XRD patterns of zeolite A and Cu2O NPszeolite A

According to Giannousi et al [4] and Xia et al [19] Cu2O

should be also formed due to the disproportionation reactionof Cu and Cu2+

Cuo + Cu++ + 2OHminus 997888rarr Cu2O +H

2O (5)

It seems that not all resultant Cu reacts with Cu2+ So thatsmall trace of Cu crystal could be contained in the Cu

2O

NPszeolite product as presented in XRD pattern in Figure 3Khan et al [18] also reported that the color of the Cu-Cu

2O

NPsmixture was dark yellowish that was different from blackcolor of CuO [20] and reddish color (or brick color) of Cu

2O

(Figure 1) According to Arshadi-Rastabi et al [21] Cu2O

NPs have various ranges of different colors namely yelloworange red and brown color

The energy-dispersive X-ray (EDX) spectra in Figure 4showed that the composition of zeolite A consists of four


3000

2500

2000

1500

1000

500

0

Cou

nts

O K

Na K

Al K

Si K

K K

K K

Zeolite A

1 2 3 4 5 6 7 8 9 100

Energy (keV)

(a)

3000

2500

2000

1500

1000

500

0

Cou

nts

O K

Cu L

Na K

Al K

Si K

Cu K

Cu K

Cu2O NPsZeolite A

1 2 3 4 5 6 7 8 9 100

Energy (keV)

(b)Figure 4 EDX spectra of zeolite and Cu

2O NPszeolite

Cu2++ zeolite Cu2+zeolite

OHminus Reduction

Cu2 NPszeolite

N2H4middotH2O

Figure 5 Brief schematic diagram of Cu2O NPszeolite synthesis procedures

main elements particularly silicon aluminum oxygensodium and a small amount of potassium but without anytrace of copper After exchange with Cu2+ and reduction ofCu2+ to Cu

2O NPs the peaks at 097 804 and 893 keV

appeared in EDX spectrum confirming the presence of cop-per in the composition of Cu

2O NPszeolite with the copper

content of about 9 (ww) In addition the copper contentanalyzed by ICP-AES was found to be of sim105 Demirci etal also reported that the copper content exchanged in zeoliteA was of about 10ndash14 (ww) [22] In the studies of Razaviand Loghman-Estarki [12] and Ramya and Kanimozhi [23]the EDX spectrum was also used to confirm the presence ofcopper in zeolite According to Razavi and Loghman-Estarkithe copper content in the zeolite is only determined in step1 (ion-exchange step) [12] Thus the second step (reductionof Cu2+ by hydrazine) could not influence the total coppercontent in the final product (Cu

2O NPszeolite)

Figure 5 presented the brief schematic diagramof the syn-thesis procedures of Cu

2ONPszeolite by chemical reduction

method using hydrazine hydrate

32 Antibacterial Activity of Cu2O NPsZeolite The antibac-terial activity of Cu2+zeolite and Cu

2ONPszeolite with cop-

per concentration of 150mgL was presented in Figure 6 and

Table 1 The antibacterial efficiency (120578) of Cu2+zeolite and Cu2O

NPszeolite

Sample E coli CFUmL 120578 Control 113 times 108 mdashCu2+zeolite 209 times 107 9815Cu2O NPszeolite 430 times 107 9619

Table 1 The obtained result indicated that the antibacterialefficiency of both Cu2+zeolite and Cu

2ONPszeolite against

E coli was of 9815 and 9619 respectivelyMost importantly according to Li et al [24] the Cu

2O

NPs have low cytotoxicity They also reported that theantibacterial efficiency of Cu

2ONPs with 4 gL against E coli

and S aureus could get 100 after 30min In our experimentwith copper concentration of 500mgL the antibacterialefficiency of Cu2+zeolite and Cu

2O NPszeolite was also

attained to nearly 100 after 4 h exposure in bacterial sus-pension (data not shown) The antimicrobial mechanism ofCu2+zeolite can be occurred through two possible pathwaysas proposed by Hu et al for Cu2+montmorillonite [25] Thefirst one is the adsorption of bacterial cells on the surfaceof the Cu2+ carriers and the second Cu2+ ions dissociated


(c)(b)(a)

Figure 6 Photograph of the growth of E coli on LB agar plates (a) control (b) Cu2+zeolite and (c) Cu2O NPszeolite

from Cu2+carriers directly interact with bacterial cells Forcopper-based nanoparticles (Cu CuO and Cu

2O nanopar-

ticles) an elusive question remains whether the release ofCu2+ ions from the copper-based nanoparticles contributesto the toxicity of these nanomaterials of the toxicity exertedfrom the nanoparticles itself [26] Gu et al [27] studied theeffect of Cu

2ONPsmontmorillonite on damage and removal

of M aeruginosa algae The obtained results indicated thatthe antialgae effect mainly depended on Cu2+ ions extentreleased from Cu

2O and ∙OH O

2

∙minus radicals generated fromphotocatalysis activity of Cu

2O NPs which were responsible

for the damage to cellular structure and physiological activityled to death of algae cells

Furthermore the acute toxicity of CuSO4sdot5H2O for rats

showed that the oral LD50was 234mgkg body weight while

oral LD50

of Cu2+-exchanged montmorillonite with coppercontent of 25 gkg was of 18 gkg body weight [25] Thisresult indicated that Cu2+-exchanged montmorillonite wasa toxicity-free substance for rats Thus it can be inferredthat Cu2+zeolite and also Cu

2O NPszeolite are less toxic

than Cu2+ ion and both products can be used as antibacterialagent especially for water treatment and agricultural applica-tion In some cases where application fields require highlyantibacterial activity and low cytotoxicity Cu

2O NPszeolite

would be more potential In addition Cu2O NPszeolite

product can be favorably produced on large scale by thisprocess The antifungal activity of Cu2+zeolite and Cu

2O

NPszeolite against Phytophthora fungi that caused severeldquofoot rotrdquo disease for pepper plant will be further evaluatedfor application in agriculture as the effective fungicides

4 Conclusions

In this study Cu2O NPs in zeolite A were synthesized using

hydrazine hydrate as a reducing agent Structural propertiesof Cu

2O NPs were determined by XRD and TEM The

Cu2O NPs have fine crystal structure with particle size of

about 40 nm Results of the antibacterial activity showed thatboth Cu2+zeolite and Cu

2O NPszeolite exhibited highly

bactericidal efficiency (120578 sim 96ndash98) Thus the obtained

products can be used as antimicrobial agent especially forwater treatment and agricultural application

Competing Interests

The authors declare that they have no competing interests

Authorsrsquo Contributions

Nguyen Quoc Hien came up with the idea Dang Van Phuand Le Anh Quoc designed and set up the experimentalprocedure Dang Van Phu and Bui Duy Du planed theexperiments and agreed with the paperrsquos publication Le AnhQuoc conducted the sizes measurement of as-prepared Cu

2O

nanoparticles by EDX TEM and XRD Nguyen Quoc Hienand Le Anh Quoc evaluated the antibacterial efficiency ofas-synthesized copper products Nguyen Quoc Hien BuiDuy Du and Dang Van Phu analyzed the data drafted themanuscript and revised themanuscript critically All authorsread and approved the final manuscript

Acknowledgments

The authors would like to thank Mr NQ Nghi and Mr NQThuy for their assistance during experimental works

References

[1] S Yokoyama H Takahashi T Itoh K Motomiya and KTohji ldquoSynthesis of metallic Cu nanoparticles by controlling Cucomplexes in aqueous solutionrdquo Advanced Powder Technologyvol 25 no 3 pp 999ndash1006 2014

[2] L Xiong Z-H Tong J-J Chen L-L Li and H-Q YuldquoMorphology-dependent antimicrobial activity of CuCu

119909O

nanoparticlesrdquo Ecotoxicology vol 24 no 10 pp 2067ndash20722015

[3] S Huang L Wang L Liu Y Hou and L Li ldquoNanotechnologyin agriculture livestock and aquaculture in China A reviewrdquoAgronomy for Sustainable Development vol 35 no 2 pp 369ndash400 2015


[4] K Giannousi G Sarafidis S Mourdikoudis A Pantazakiand C Dendrinou-Samara ldquoSelective synthesis of Cu

2O and

CuCu2O NPs antifungal activity to yeast saccharomyces cere-

visiae and DNA interactionrdquo Inorganic Chemistry vol 53 no18 pp 9657ndash9666 2014

[5] S Lee C W Liang and L W Martin ldquoSynthesis control andcharacterization of surface properties of Cu

2O nanostructuresrdquo

ACS Nano vol 5 no 5 pp 3736ndash3743 2011[6] W ZWang GHWang X SWang Y J Zhan Y K Liu andC

L Zheng ldquoSynthesis and characterization of Cu2O nanowires

by a novel reduction routerdquo Advanced Materials vol 14 no 1pp 67ndash69 2002

[7] H Xu W Wang and W Zhu ldquoShape evolution andsize-controllable synthesis of Cu

2O octahedra and their

morphology-dependent photocatalytic propertiesrdquoThe Journalof Physical Chemistry B vol 110 no 28 pp 13829ndash13834 2006

[8] R Wick and S D Tilley ldquoPhotovoltaic and photoelectrochem-ical solar energy conversion with Cu

2Ordquo Journal of Physical

Chemistry C vol 119 no 47 pp 26243ndash26257 2015[9] J Ren W Wang S Sun L Zhang L Wang and J Chang

ldquoCrystallography facet-dependent antibacterial activity thecase of Cu

2Ordquo Industrial amp Engineering Chemistry Research vol

50 no 17 pp 10366ndash10369 2011[10] P Payra and P K Dutta Handbook of Zeolite Science and

Technology Marcel Dekker Inc New York NY USA 2003[11] H Jahangirian M H Shah Ismail M Jelas Haron et al

ldquoSynthesis and characterization of zeoliteFe3O4nanocompos-

ite by green quick precipitation methodrdquo Digest Journal ofNanomaterials and Biostructures vol 8 no 4 pp 1405ndash14132013

[12] R S Razavi and M R Loghman-Estarki ldquoSynthesis andcharacterizations of copper oxide nanoparticles within zeoliteYrdquo Journal of Cluster Science vol 23 no 4 pp 1097ndash1106 2012

[13] P Sutradhar M Saha and D Maiti ldquoMicrowave synthesis ofcopper oxide nanoparticles using tea leaf and coffee powderextracts and its antibacterial activityrdquo Journal of Nanostructurein Chemistry vol 4 article 86 2014

[14] A Q Le V P Dang N D Nguyen C T Vu and Q H NguyenldquoPreparation of polypropylenesilver nano-zeolite plastics andevaluation of antibacterial and mechanical propertiesrdquo Interna-tional Journal of Composite Materials vol 6 no 4 pp 89ndash942016

[15] D Van Phu L A Quoc N N Duy et al ldquoStudy on antibacterialactivity of silver nanoparticles synthesized by gamma irradi-ation method using different stabilizersrdquo Nanoscale ResearchLetters vol 9 article 162 2014

[16] S P Dimitrijevic Z J Kamberovic M S Korac Z M Anđic SB Dimitrijevic andN S Vukovic ldquoInfluence of reducing agentsand surfactants on size and sharp of silver fine powder particlesrdquoAssociation of Metallurgical Engineers of Serbia vol 20 pp 73ndash87 2014

[17] C H Kuo and M H Huang ldquoFacile synthesis of Cu2O

nanocrystals with systematic shape evolution from cubic tooctahedral structuresrdquo Journal of Physical Chemistry C vol 112no 47 pp 18355ndash18360 2008

[18] A Khan A Rashid R Younas and R Chong ldquoA chemicalreduction approach to the synthesis of copper nanoparticlesrdquoInternational Nano Letters vol 6 no 1 pp 21ndash26 2016

[19] X Xia C Xie S Cai Z Yang and X Yang ldquoCorrosion charac-teristics of copper microparticles and copper nanoparticles indistilled waterrdquoCorrosion Science vol 48 no 12 pp 3924ndash39322006

[20] N R Dhineshbabu V Rajendran N Nithyavathy and RVetumperumal ldquoStudy of structural and optical properties ofcupric oxide nanoparticlesrdquo Applied Nanoscience vol 6 no 6pp 933ndash939 2016

[21] S Arshadi-Rastabi J Moghaddam and M R EskandarianldquoSynthesis characterization and stability of Cu

2Onanoparticles

produced via supersaturation method considering operationalparameters effectrdquo Journal of Industrial and Engineering Chem-istry vol 22 pp 34ndash40 2015

[22] S Demirci Z Ustaoglu G A Yılmazer F Sahin and NBac ldquoAntimicrobial properties of zeolite-X and zeolite-A ion-exchanged with silver copper and zinc against a broad range ofmicroorganismsrdquo Applied Biochemistry and Biotechnology vol172 no 3 pp 1652ndash1662 2014

[23] D Ramya and S Kanimozhi ldquoA comparative study of zeoliteloaded copper oxide and iron oxide nanoparticles and its effecton antibacterial and antifungal activity against six bacterial andthree fungal isolates of secondary effluentrdquo International Journalof Development Research vol 4 pp 1847ndash1857 2014

[24] P Li W Lv and S Ai ldquoGreen and gentle synthesis of Cu2O

nanoparticles using lignin as reducing and capping reagent withantibacterial propertiesrdquo Journal of Experimental Nanosciencevol 11 no 1 pp 18ndash27 2016

[25] C H Hu Z R Xu and M S Xia ldquoAntibacterial effect ofCu2+-exchanged montmorillonite on Aeromonas hydrophilaand discussion on its mechanismrdquoVeterinaryMicrobiology vol109 no 1-2 pp 83ndash88 2005

[26] G Applerot J Lellouche A Lipovsky et al ldquoUnderstanding theantibacterial mechanism of CuO nanoparticles revealing theroute of induced oxidative stressrdquo Small vol 8 no 21 pp 3326ndash3337 2012

[27] N Gu J Gao H Li Y Wu Y Ma and K WangldquoMontmorillonite-supported with Cu

2O nanoparticles for

damage and removal of Microcystis aeruginosa under visiblelightrdquo Applied Clay Science vol 132-133 pp 79ndash89 2016

Submit your manuscripts athttpswwwhindawicom

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NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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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


sodium hydroxide and calcification at 350∘C for 2 h wasstudied by Razavi and Loghman-Estarki [12] In the presentstudy Cu

2O NPs were synthesized within the zeolite A

framework using CuSO4as copper precursor and hydrazine

hydrate (N2H4sdotH2O) as reducing agent The antibacterial

activity of the obtained Cu2ONPszeolite against Escherichia

coli (E coli) was also investigated

2 Methods

21 Materials and Chemicals Analytical grade CuSO4sdot5H2O

NH4OH (25) and N

2H4sdotH2O (80) were products from

Merck and industrial grade sodium type of zeolite A withchemical formulation Na

2OsdotAl2O3 2SiO

2sdot45H2O was a

product from Shangdong Aluminium Corporation (SALCOChina) The Luria-Bertani (LB) medium for bacterial incu-bation was purchased from Himedia India The strain of Ecoli ATCC 6538 was provided by the University of MedicalPharmacy Ho Chi Minh City Distilled water was used in allexperiments

22 Exchange of Cu2+ Ions in Zeolite 1 kg of zeolite wassuspended into a glass beaker containing 15 L water ThenHNO

32N and water were added to zeolite suspension

mixture for neutralization to pH sim65 and for final volume ofabout 4 L 042 kg of CuSO

4sdot5H2O was dissolved in 500mL

water and then poured slowly into neutralized zeolite sus-pension mixture Stirring was carried out for 2 h at ambienttemperature for complete exchange of Cu2+ into zeoliteBefore adding hydrazine pH of the Cu2+zeolite mixture wasadjusted by ammonia water to sim75

23 Reduction of Cu2+ to Cu2O NPs in Zeolite A freshlyprepared 250mL hydrazine 20 (wv) solution was addeddropwise to the above Cu2+zeolite under stirring for 2 h atambient temperature Then reduction reaction was stoppedand let standing overnight for Cu

2O NPszeolite settling

down Finally Cu2O NPszeolite product was filtered off

using cotton fabric washed several times with water anddried in a forced air oven at 60∘C till to constant weight

24 Characterization of Cu2O NPsZeolite The content ofcopper in Cu

2O NPszeolite product was determined by

inductively coupled plasma-atomic emission spectroscopy(ICP-AES) on a Perkin-Elmer Optima 5300DV X-raydiffraction (XRD) of Cu

2O NPszeolite product was carried

out onD8Advance Bruker Germany and theCu2ONPs sizes

were measured using a transmission electron microscope(TEM JEM1010 JEOLTokyo Japan)Thepresence of copperin Cu

2O NPszeolite was also assessed by energy-dispersive

X-ray spectroscopy (EDX) on a JEOL 6610 LA

25 Antibacterial Activity of Cu2O NPsZeolite In vitro testof bactericidal activity of Cu2+zeolite and Cu

2O NPszeolite

against E coli was carried out following the procedure asdescribed in [13ndash15] Briefly the antibacterial activity of thematerials was tested by culture medium toxicity method

in Luria-Bertani medium The test material samples andcontrol were shaken in E coli suspension at 150 rpm at roomtemperature for 4 h After that the number of viable bacteriain eachmixture was determined by spread plate technique onLB agar plates The antibacterial efficiency (120578) was calculatedusing the equation 120578 () = (119873

119900minus 119873) times 100119873

119900 where 119873

119900

and119873 are the survival numbers of bacteria in the control andstudied samples respectively

3 Results and Discussion

31 Characterization of Cu2O NPsZeolite Figure 1 showedthe photograph of zeolite Cu2+zeolite and Cu

2O NPszeo-

lite It is clearly observed from Figure 1 that Cu2ONPszeolite

is reddish color The reaction of hydrazine used as reducingagent can be expressed by

N2H4+ 4OHminus 997888rarr N

2+ 4H2O + 4eminus (1)

Dimitrijevic et al reported that hydrazine hydrate has beenconsidered as a preferred reducing agent and used forindustrial scale production of silver powder for decades [16]According to Kuo and Huang [17] in base medium theformation of Cu

2O NPs can be described in the following

reactions

2Cu (OH)4

2minus +N2H4+ 2OHminus

997888rarr Cu2O +N

2+ 5H2O + 4OHminus

(2)

Cu2O + Cu

2O + Cu

2O + sdot sdot sdot 997888rarr Cu

2O nano (3)

TEM images of zeolite and Cu2O NPszeolite in Figure 2

indicated that the size of Cu2ONPs in the frameworks of the

zeolite was in the range from 5 to about 30 nm It can be alsosurprisingly observed in Figure 2 that beside the black dotssome parts of the morphology of Cu

2O NPs in zeolite were

almost as wormlike formThese Cu2ONPs seem to be linked

together within the intercages of zeolite structureThe XRD pattern of Cu

2O NPszeolite A in Figure 3

showed that diffraction peaks appeared at 2961∘ 3648∘4238∘ 6146∘ 7356∘ and 7752∘ corresponding to (110) (111)(200) (220) (311) and (222) planes of cuprite respectivelythat indicated the formation of Cu

2O nanocrystals (JCPDS

Card number 05-0667) [4 18] The average crystalline sizeof Cu

2O NPs determined by taking the full width at half

maximum (FWHM) of the most intense peak at 3648∘using Debye-Scherrerrsquos formula [18] was of about 40 nmThe crystalline size calculated from XRD patterns is usuallybigger than that from TEM images that also happened inour previous study [14] and in this study as well Therewas not any diffraction peak in XRD pattern in Figure 3assigned for CuO nanocrystal however low intensity peaksalso appeared at 4336∘ 5043∘ and 7425∘ that assigned forCu nanocrystals (JCPDSCard number 04-0836) [4 12]Thusduring reduction reactions a certain small amount of Cucould be formed in the following reaction

2Cu2+ +N2H4+ 4OHminus 997888rarr 2Cuo + N

2+ 4H2O (4)


(c)(b)(a)


(a) (b)


CuNPsZeoliteZeolite

Cou

nts



∘

(110)Cu2O3648

∘

(111)

Cu2O4238

∘

(200)Cu

4336∘

(111) Cu5043

∘

(200)

Cu2O6146

∘

(220)Cu2O7356

∘

(311)

Cu7425

∘

(220)Cu2O7752

∘

(222)


2120579 (∘)8070605040302010





2O (5)


2O


2O


2O





3000

2500

2000

1500

1000

500

0

Cou

nts

O K

Na K

Al K

Si K

K K

K K

Zeolite A

1 2 3 4 5 6 7 8 9 100

Energy (keV)

(a)

3000

2500

2000

1500

1000

500

0

Cou

nts

O K

Cu L

Na K

Al K

Si K

Cu K

Cu K

Cu2O NPsZeolite A

1 2 3 4 5 6 7 8 9 100

Energy (keV)


2O NPszeolite


OHminus Reduction

Cu2 NPszeolite

N2H4middotH2O







2O NPszeolite)








NPszeolite





2O







(c)(b)(a)



2O nanopar-




2O and ∙OH O

2






oral LD50




2O NPszeolite



2O


4 Conclusions









Competing Interests




2O


Acknowledgments


References



119909O





2O and































2Onanoparticles


















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




(c)(b)(a)


(a) (b)


CuNPsZeoliteZeolite

Cou

nts



∘

(110)Cu2O3648

∘

(111)

Cu2O4238

∘

(200)Cu

4336∘

(111) Cu5043

∘

(200)

Cu2O6146

∘

(220)Cu2O7356

∘

(311)

Cu7425

∘

(220)Cu2O7752

∘

(222)


2120579 (∘)8070605040302010





2O (5)


2O


2O


2O





3000

2500

2000

1500

1000

500

0

Cou

nts

O K

Na K

Al K

Si K

K K

K K

Zeolite A

1 2 3 4 5 6 7 8 9 100

Energy (keV)

(a)

3000

2500

2000

1500

1000

500

0

Cou

nts

O K

Cu L

Na K

Al K

Si K

Cu K

Cu K

Cu2O NPsZeolite A

1 2 3 4 5 6 7 8 9 100

Energy (keV)


2O NPszeolite


OHminus Reduction

Cu2 NPszeolite

N2H4middotH2O







2O NPszeolite)








NPszeolite





2O







(c)(b)(a)



2O nanopar-




2O and ∙OH O

2






oral LD50




2O NPszeolite



2O


4 Conclusions









Competing Interests




2O


Acknowledgments


References



119909O





2O and































2Onanoparticles


















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




3000

2500

2000

1500

1000

500

0

Cou

nts

O K

Na K

Al K

Si K

K K

K K

Zeolite A

1 2 3 4 5 6 7 8 9 100

Energy (keV)

(a)

3000

2500

2000

1500

1000

500

0

Cou

nts

O K

Cu L

Na K

Al K

Si K

Cu K

Cu K

Cu2O NPsZeolite A

1 2 3 4 5 6 7 8 9 100

Energy (keV)


2O NPszeolite


OHminus Reduction

Cu2 NPszeolite

N2H4middotH2O







2O NPszeolite)








NPszeolite





2O







(c)(b)(a)



2O nanopar-




2O and ∙OH O

2






oral LD50




2O NPszeolite



2O


4 Conclusions









Competing Interests




2O


Acknowledgments


References



119909O





2O and































2Onanoparticles


















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




(c)(b)(a)



2O nanopar-




2O and ∙OH O

2






oral LD50




2O NPszeolite



2O


4 Conclusions









Competing Interests




2O


Acknowledgments


References



119909O





2O and































2Onanoparticles


















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





2O and































2Onanoparticles


















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



Synthesis and Investigation of Antimicrobial Activity of O...

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