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1

A

M. Sc. Research Project Report on

Supported Silver Nanoparticles: Synthesis,

Characterization and Catalytic Studies

Submitted by,

Mr. Aamer S.K.R.

Under the guidance of,

Dr. Sagar D. DelekarAssistant Professor,

Department of Chemistry,

Dr.Babasaheb Ambedkar Marathwada University, Aurangabad

Sub-campus Osmanabad 413 501 (M.S.) India

2011-2012


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Objectives

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Synthesis of supported silver nanoparticles

using Chemical reduction method.

Characterization of synthesized catalyst by various

spectroscopic methods such as XRD, FT-IR, TEM,

EDAX and UV-Visible measurement

catalytic activity of supported Silver NPs for

reduction of aromatic nitro compounds


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Why Silver?

Nobel Metal,

Low cost

Antimicrobial activity

Electrical conductivity-High

light response occur in the visible regime

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Methodology

4

Sol-gel

Electrochemical Deposition

Laser

Chemical reduction


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Chemical Reduction Method

Advantages: Able to generate special shaped nanoparticles

Low temperature synthesis

Simpler technology

The lower cost

Less instrumentation

Self assembling

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5mL 0.001 M Silver Nitrate+

6mL 0.01M Dextrose

Reduced Silver

10mL 0.009M SDS solution

Colloidal Silver Nanoparticles

Colloidal Silver NPs

+

TiO2 NPs

Silver supported

TiO2 Nanocatalyst

Synthesis Route

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Characterization

UV-Visible Spectroscopy

X-Ray Diffraction (XRD) Studies

Transmission Electron Microscopy (TEM)

Energy Dispersive X-Ray Analysis (EDAX)

Fourier Transmission- Infrared Spectroscopy (FT-IR)

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Results and discussion

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200 300 400 500 600 700 800

0.0

0.1

0.2

0.3

0.4

0.5

Ag NPs

Ab

sorbance

Wavelength (nm)

Figure 1A: UV- Visible spectra of colloidal Silver Nanoparticles.

UV-VISIBLE STUDIES

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300 400 500 600 700 800

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

c

b

a

a= after 1 monthb= after 2 month

c= after 3 month

Absorbance

Wavelength (nm)

Figure 1B: UV-Vis Spectrum of Silver Nanoparticles

for stability measurements

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300 400 500 600 7000.0

0.2

0.4

0.6

0.8

1.0

b

a

Ab

sorbance

Wavelength nm

a-Ag-TiO2

b-TiO2

Figure 1C: UV-Visible spectra of Supported Silver Nanoparticles

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X-RAY DIFFRACTION STUDIES

20 40 60 800

2000

4000

6000

8000

10000

(400)

b

a

(312)

(215)

(220)

(116)

(204)

(105)

(200)

(004)

(101)

(111)In

tensity(A.U

.)

a- Ag-TiO2[JCPDS#22-1272]

b- TiO2[JCPDS#03-0939]

Figure 2: XRD patterns of TiO2and Ag supported TiO2 nanoparticles.

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TRANSMISSION ELECTRON

MICROSCOPY

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Figure 3a: TEM image of

pure TiO2 NPs

Figure 3b: TEM image of

Ag supported TiO2 NPs.


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ENERGY DISPERSIVE X-RAY

ANALYSIS

Figure 4: EDAX pattern of 1 mole% Ag supported TiO2 NPs

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FOURIER TRANSMISSION

INFRARED SPECTROSCOPY

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4000 3500 3000 2500 2000 1500 1000

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

1.05

1.10

1098

1066

1226

1216

a

b

Transm

ittance%

Wavenumber (cm-1

)

Figure 5: FT-IR spectra of pure SDS and SDS capped NPs:

a) Pure SDS; b) SDS Capped Silver NPs


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CATALYTIC ACTIVITY

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Reduction of 4-nitrophenol to 4-aminophenol using

silver NPs supported on TiO2 as catalysts


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250 300 350 400 450 500

0.0

0.1

0.2

0.3

e

dc

b

a

Ab

sorbance

Wavelength (nm)

a= 4NP

b= 4NP+NaBH4

c= 10mind= 20min

e= 30min

Figure 6: UV-Visible spectra of catalytic study of reduction of 4-NP to 4-AP.

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Conclusions

Successful synthesis of silver NPs by chemical

reduction method.

Simplicity and stability

Supported silver NPs on TiO2 have been best materials

for the reduction of aromatic nitro compounds.

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