A

PROJECT REPORT

ON

GREEN SYNTHESIS OF METAL

NANOPARTICLES

Submitted By: Guided By:

Darshan Khunt, Vasu Bharuchi Dr. Shibu G. Pillai 12BCH012, 12BCH004 Asst. Professor

CHEMICAL ENGINEERING DEPARTMENT

INSTITUTE OF TECHNOLOGY

NIRMA UNIVERSITY

CERTIFICATE

This is to certify that Mr. Darshan Khunt (12BCH012), student of Chemical

Engineering, VII semester, of Nirma University, has satisfactorily completed the

minor project on “Green Synthesis of Metal Nanoparticles” as a partial fulfillment

towards the degree of B. Tech. in Chemical Engineering.

Date:

Place: Ahmedabad

Dr. Shibu G. Pillai Dr. S. S. Patel

Assistant Professor Head of Department

CONTENT

Page No.

Acknowledgement I

Abstract II

List of Figure III

List of Tables III

Chapter

No.

Title Page No.

1. Scope of Project 1

2. Introduction 2

3. Resources 3-6

3.1 Green Tea Composition 3

3.2 Synthesis 4

3.2.1 Commonly used plant 4

3.2.2 Derived from Agrowaste 5

3.2.3 Other plant species 5

3.3 Characterization 6

4. Experimentation 7-8

5. Prospective Work 9

References 10-11

I

ACKNOWLEDGMENT

We would like to express profound gratitude to our guide Dr. Shibu G. Pillai for his

support, encouragement, supervision and useful suggestions regarding project. His moral guidance

and support enabled us in accomplishing our work.

Also, we would like to express gratitude to Amita Chaudhary Madam for her involvement

and support in fulfilling our task of project. She helped us with her immense knowledge in the

field on Nanotechnology.

Finally, we thank our departmental head Dr. S. S. Patel Sir for including this project course

in our B.Tech Curriculum.

II

ABSTRACT

The nanotechnology has gained attention to emerging world in medical technology. Its various

application such as Magnetic resonance Imaging, magnetic strips and so forth provides a need for

fulfilling demand. In this work, we made iron nanoparticle in range 50-90nm. The black

appearance of solution approved the presence of nanoparticle. We performed a series of

nanoparticle synthesization and were able to develop nanoparticle. However, we were unable to

accomplish magnetic properties. To accomplish paramagnetic properties, we need to reduce

nanoparticle size to 5-10nm. Hence, we will synthesize nanoparticle in closed medium with aid of

high design pressure pipe tightly bolted on both ends.

III

List of Figure

Figure

No. Description

Page

No.

Figure 1 Commercially available green tea after crushing 7

Figure 2 Green tea preparation 8

Figure 3 Formation of black precipitate of iron nanoparticle 9

List of Tables

Table

No Description

Page

no

Table 1 Green Tea Composition 4

1

1. Scope of Project

The primary purpose of the project is to synthesize the iron nanoparticles by greener reducing

agent and capping agent, which is comparatively less toxic or innocuous, compared to previous

chemical and physical method. The size distribution of nanoparticle is 1-100 nm. The properties

and its real world application is directly dependent on size of nanoparticles synthesized. For

example, in biomedical applications like magnetic resonance imaging, magnetic cell separation or

magnetorelaxometry, where size of particle is most crucial.

The main focus is on synthesizing magnetic iron nanoparticle due to various medical application

such as high-sensitivity biomolecular magnetic resonance imaging (MRI) for medical diagnosis

and therapeutics, target drug delivery, magnetic ink for jet printers and many so forth. Iron

nanoparticles are being used to clean up carbon tetrachloride pollution in ground water and clean

arsenic from water wells.

The key applications of iron oxide nanoparticles are as follows:

• In magnetic resonance imaging to provide enhanced contrast at very low concentrations in

the nanomolar range for studying tumors

• As a targeted delivery vehicle and as a drug delivery coating for nanoscale anti-cancer

drugs

• For magnetic data storage in hard drives and discs.

• In coatings, plastics, nanowires, nanofibers, and textiles and in specific alloy and catalyst

applications.

• Extensive laboratory studies have demonstrated that nanoscale iron particles are effective

for the treatment of a wide array of common groundwater contaminants such as chlorinated

organic solvents, organochlorine pesticides, polychlorinated biphenyls (PCBs), organic

dyes, and various inorganic compounds.[18]

2

2. Introduction

The molecular or atomic modification of particle termed as nanoparticle. Metallic nanopartic les

have generated an immediate attraction for their awry applications in optoelectronic and

physicochemical properties. Metallic nanoparticles can easily be synthesised using chemical and

physical methods. However, toxicity of chemical opens a way for greener synthesis.

Toxicity in environment has been major concern even on a ppm level. The reducing agent and

capping agent used in conventional method of nanoparticle development pose eminent threat to

biological environment. In addition, these method intricate unfavourable conditions making them

quite expensive.

The biological method of nanoparticle has proved to be cost effective environmental friendly in

response to conventional method. Consequently, nanoparticle have been synthesised using plant

extracts and microorganisms. Plant extract provides a biohazard and maintains an elaborate

process for cell culture. Silver and gold nanoparticles have been synthesised using various plant

extracts such as sorghum extract, hibiscus (Hibiscus rosa sinensis) leaf extract, neem (Azadirachta

indica) leaf broth, black tea leaf extracts, Indian gooseberry (Emblica officinalis) fruit extract,

sundried camphor (Cinnamomum camphora) leaves, and Aloe vera plant extract.[1]

Recently, iron and silver nanoparticles have been synthesised used tea leaves and coffee bean

extracts. Iron nanoparticles of different size and morphologies were also formed instantaneous ly

using tea extracts. The tea extract prepared nanoparticles were found to be innocuous compared to

conventional NaBH4 reduction.

Iron nanoparticle is mostly unexplored area of nanotechnology apart from a quite research in

elements such as Zinc, Gold, Platinum and Silver. The magnetic properties helps them to adhere

to surface and area of application in ferromagnetic medium. Magnetic nanoparticles have emerged

as new class of nanoparticle as such they poses exceptional properties like supermagnetism,

coercivity, and much more [20].

3

3. Resources

The greener synthesis of nanoparticles have unfair advantage of conventionally used physical and

chemical methods.

a) clean and eco-friendly method, as toxic chemicals are not used [2];

b) the active biological component like enzyme itself acts as a reducing and capping agent,

thereby reducing the overall cost of the synthesis process [2];

c) small nanoparticles can be produced even during large-scale production [3];

d) External experimental conditions like high energy and high pressure are not required,

causing significant energy saving [4].

Till now, iron nanoparticles (nZVI and iron oxide) have been mainly prepared using different plant

extracts. Plant extracts act as low-cost reducing and stabilizing agents. Magnetic nanopartic le

synthesis is carried out at room temperature or by the hydrothermal route by mixing plant extract

with metal salt solution in a fixed ratio.

3.1 Green tea composition

Green tea ingredients are extremely complex. It contains as many as 200 bioactive compounds.

Not only are they complex, being plant material, their levels also extreme variable and change with

location, harvesting season and making process. The largest and most important chemical

compound is polyphenols. Why are polyphenols so important? This is because they contain

flavonoids - an important class of antioxidants. But high levels of polyphenols make bad green tea.

This is because they are astringent (a dry mouth feeling) tasting. Therefore Chinese and Japanese

green tea plants tend to have lower level of polyphenols than black tea plants.

Green tea drinkers are compensated by the presence of another delicious compound: theanine. The

best green tea is harvested in spring when the theanine to polyphenol ratio is the highest. Green

tea also contains organic acids such as gallic and quinic acids, and 10% to 15% of carbohydrate

and small amount of volatiles.

4

Eventually, the presence of naturally occurring catechins and other polyphenols act as a reducing

as well as capping agent during formation of iron nanoparticles. [19]

Table 1: Composition of green tea

Concentration (mg/L)

Potassium 92-151

Sodium 35-69

Calcium 1.9-3.5

Fluoride 0.8-2

Aluminium 1-2.2

Manganese 0.52-1.9

Iron 0.02-0.128

Chromium -

Selenium -

Catechins

Epigallocatechin gallate (EGCG) 117-442

Epicatechins 3-gallate (EGC) 203-471

Epigallocatechin (ECG) 16.9-150

Epicatechim (EC) 25-81

Catechin (C) 9.03-115

Caffeine 141-338

3.2 Synthesis

3.2.1 Commonly used plant

The frequently used plant extract for synthesis of iron nanoparticles is tea extracts were synthesized

by Hoag et al [5] by allowing Camellia Sinensis (green tea) extract to react with 0.1M FeCl3

solution. In another work, the synthesis was carried out at room temperature using different

volumes of tea extract and Fe(NO)3 solution to check the effect of on size of nanoparticle due to

increased concentration[8]. Ting Wang et al [7] synthesized iron nanoparticles, GT-Fe NPs using

green tea and ferrous sulphate (FeSO4) to serve as Fenton-like catalyst for the degradation of

5

cationic dyes. In a similar approach, Shahwan et al. [8] green tea extract was used with FeCl2.4H2O

as Fenton-like catalyst for degradation of aqueous anionic and cationic dyes[9]. Kuang et al. [10]

used three different tea extracts, namely, green tea (GT), oolong tea (OT), and black tea (BT) to

synthesize iron nanoparticles.

3.2.2 Derived from Agrowaste

One of the major drawbacks of using plant resources for nanoparticle synthesis is the destruction

of plants and plant parts. A possible way to avoid this and to serve the additional purpose of

pollution mitigation is to employ agrowaste, which is otherwise a significant source of pollut ion.

Some authors have used agrowastes as low-cost bioreducing agents.

Njagi et al. [5] used aqueous Sorghum sp. (hybrid sorghum) bran extract for nZVI synthesis. The

extract was prepared by obtaining sorghum bran powder in double-distilled water at different

temperatures for half an hour. Eucalyptus globulus leaf extract was used by Madhavi et al. [11] as

a bioreducing agent to synthesize nZVI. Polyphenol compounds in plant extract like oenothein B

were identified to be responsible for the synthesis and stabilization of nZVI. Wang [12]

synthesized iron nanoparticles using eucalyptus leaf extract by adding 0.1MFeCl3 solution in a

ratio of 1: 2. Wang et al. [13] synthesized polydispersed iron nanoparticles employing eucalyptus

leaf extract obtained from its leaf litter. nZVI, Fe3O4, and Fe2O were the different forms of

nanoparticles synthesized during the process. Fe0/Fe3O4 nanoparticles were successfully

synthesized using pomegranate leaf extract by Rao et al. [14]. Venkateswarlu et al. [15] used

plantain peel extract as a low-cost bioreducing agent for synthesizing magnetite nanoparticles. Iron

salt solution was hydrolyzed, resulting in the formation of ferric hydroxide, which was

subsequently reduced by various biomolecules to form Fe3O4 nanoparticles.

3.2.3 other plant species

Senthil and Ramesh [16] reportedthe green synthesis of Fe3O4 nanoparticles at room temperature

using leaf extract of Tridax procumbens. Carbohydrates present in the plant extract were

responsible for nanoparticle synthesis. Kumar et al. [17] synthesized stable iron oxide (Wuestite)

using aqueous extract of Terminalia chebula dry fruit pericarp. The as-synthesized nanopartic les

6

were pure iron oxide (confirmed by energy dispersive X-ray spectroscopy (EDS)) and stable up to

21 days. The phytochemicals in the extract acted as reducing and capping agent.

.

3.3 Characterization

Various characterization techniques have been employed to determine formation of nanopartic les

as shown below:

1. Transmission Electron Microscopy (TEM)

2. X-Ray Diffraction (XRD)

3. High Resolution X-Ray Photoelectron Spectroscopy (HR-XPS)

4. X –Ray absorption near edges structure (XANES)

5. Acoustic spectrometer

6. BET nitrogen adsorption isotherm

7. Barrett–Joyner–Halenda (BJH) method.

7

4. Experimentation

In the work of synthesizing nanoparticle and its characterization, we produce a higher range

nanoparticle (>50nm). 1 gm of commercially available green tea was used to boil it in 100ml of

water at 90oC for about half an hour and then, the extract was filtered. 0.1M FeSO4 solution was

added to green tea extract at room temperature and sudden disappearance of black color shows

presence of iron particles. Mixture was continuously stirred for 30 min and then were filtered with

whatman filter paper to remove higher size particles at room temperature for about 20 hr. The

filtrate collected was dried in hot air oven at 800C for 15 hours. The dried product collected was

washed with methanol. Methanol was evaporated to obtain powdered iron nanoparticle of about

more than 50nm. The same results were obtained using FeCl3 and tea extract, except more particles

were produced.

Furthermore, we tried to synthesize magnetic iron oxide nanoparticle using above approach with

some deviation. Out of more than 5 experimental trials, the most common approach was using the

freshly prepared iron nanoparticle were equally segregated. One was kept for drying at 70oC for

about 4 days in hot air oven with constant addition of water and therefore not allowing it to get

Fig. 1 Commercially available green tea after crushing

8

dried. Thereafter, it was filtered with whatman filter, washed with methanol solution thrice and

was subjected to 12h of dry air oven to get crystalline nanoparticles. Another solution had

undergone the same procedure after being filtered out from whatman filter paper. The more

nanoparticles were obtained in latter part. However, after all this trials we were unable to reach to

desired result.

Consequently, these nanoparticles formed were passive to magnetic field of a magnet. This showed

absence of their magnetic nature despite formation of nanoparticles. The reason that I think is

presence of more than required organic have led to decreased magnetic behavior. Organic material

left out from green tea extract are not magnetic in nature.

Fig. 3 Formation of black precipitate of iron nanoparticle

Fig. 2 Green tea preparation

9

5. Prospective work

Next, we plan to perform some closed system operations on freshly-prepared filtered

nanoparticles. This is in response to organic matter accumulation alongside nanoparticle and

reducing size further. The process involves using an iron pipe about 3-5 cm in length with both

closed caps and can store about 50ml solution. The pipe container is filled 4/5th with nanopartic le

solution and sealed for both side with the help of caps. Then, the pipe is kept in radiator for 4-5

days followed by 10h of microwave heating to obtain a thick paste-like nanoparticle solution. This

process is called hydrothermal carbonization (HTC). HTC involves degradation of organic

material in form of gases such as CO2, NOx.

Iron magnetic nanoparticle developed will be used to clean water by degrading oil and other

impurities. Iron nanoparticle has vast range of application and doesn’t easily degrade while not

harmful to environment.

Later, if we are successful in synthesizing iron nanoparticle via greener way, we would like to

further our research on different metal nanoparticle like zinc, silver, manganese etc.

10

Reference:

[1] Mihir Herlekar, Siddhivinayak Barve, and Rakesh Kumar, Green synthesized iron

nanoparticles by green tea and eucalyptus leaves extracts used for removal of nitrate in

aqueous solution, Journal of Nanoparticles, Volume 2014, Article ID 140614, 9 pages

[2] S. Senapati, A. Ahmad, M. I. Khan, M. Sastry, and R. Kumar, “Extracellular biosynthesis of

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3303– 3305, 2004.

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2011..

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[8] T. Shahwan, S. Abu Sirriah, M. Nairat et al., “Green synthesis of iron nanoparticles and their

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[10] J.H.Kim, P. G.Tratnyek, andY. S.Chang, “Rapid dechlorination of polychlorinated dibenzo-

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11

[11] V. Madhavi, T. N. V. K. V. Prasad, A. V. B. Reddy, B. Ravindra Reddy, and G. Madhavi,

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[12] Z. Wang, “Iron complex nanoparticles synthesized by eucalyptus leaves,” ACS Sustainab le

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[14] A. Rao, A. Bankar, A. R. Kumar, S. Gosavi, and S. Zinjarde, “Removal of hexavalent

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[18] http://www.azonano.com/article.aspx?ArticleID=3337, Sep 10, 2015

[19] http://www.amazing-green-tea.com/green-tea-ingredients.html#sthash.DVCfaSWm.dpuf,

Sept 15 2015.

[20] en.wikipedia.org/wiki/Iron_oxide_nanoparticles, 16 sept 2015.