1. Application of Nanotechnology to synthsis siver using lemeon leaves Dr
Application of Nanotechnology to synthsis siver using lemeon leaves Dr. R. Senthilkumar Head of Chemical Unit, College of Applied Sciences, Ministry of Higher education, suhar, sultanate of Oman
Co-authors:
Khadija Abdullah Ali AL-Hinaai, B.S.Naveen L.Govindarajan,K.Saravanakumar, Thirumurugan Shanmugam
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

2. 1- Introduction Scope on Nanotechnology Nanoparticles
Synthesis Methods
Chemical reduction and Biosynthesis
Application of silver nanoparticles
Sensors
Anticancer
Antibacterial activities
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

3. PROJECT OBJECTIVES
To produce potential silver nanoparticles for industrial application.
To investigate suitable natural and chemical methods for the synthesis of silver nanoparticles.
To carry out experiment for the synthesis of silver nanoparticles.
To carry out instrumentation analysis to validate the results.
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

4. 2- Materials &Methodology
20 grams of Citrus lemon leaves for bio extraction.
100 ml of M AgNO3.
100 ml of M NaBH4.
Conical flasks.
Magnetic stirrer and stir bar.
Ice bath.
UV – Visible spectrophotometer
TEM and SEM analysis
COD vials, COD thermo reactor and COD meter
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

5. Methodology A- Preparation of lemon leaves extract
Fig.1A Fresh lemon leaves
Fig.1B 20 g of small pieces of lemon leaves
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

6. Preparation of lemon leaves extract
Methodology
Preparation of lemon leaves extract
Fig.1C the lemon leaves in boiling distilled water
Fig.1D lemon leaves extract after filtration
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

7. B- Synthesis of silver nanoparticles using lemon leaves
Methodology
B- Synthesis of silver nanoparticles using lemon leaves
10 milliliter of leaves extract prepared in the previous step was added to 50 ml M AgNO3 solution in a conical flask at room temperature in the dark. After one hour the formation of the nanoparticles started. This was noticed by the color change from yellow to brown color (Figure 2) and periodic sampling using UV-Visible spectrophotometer.
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London
Figure 2 Silver nanoparticles formed by lemon leaves extract

8. C- Synthesis of silver nanoparticles using NaBH4
Methodology
C- Synthesis of silver nanoparticles using NaBH4
30 ml of NaBH4
ml of AgNO3
Added by drop/ second
With continuous stirring
Figure 3. the synthesis setup of silver nanoparticles using NaBH4.
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

9. D- Characterization and analysis of the formed nanoparticles
Methodology
D- Characterization and analysis of the formed nanoparticles
UV- Visible Spectral analysis
SEM analysis (Scanning Electron Microscopy)
TEM analysis (Transmission Electron Microscopy)
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

10. E- Applications of the formed nanoparticles
Methodology
E- Applications of the formed nanoparticles
- Method of examine the formed nanoparticles in COD reduction for textile waste water
To find COD of the sample, one drop of the sample was added to COD vial and it was left in COD thermo reactor for 120 minutes at 150o C. After 2 hours the vial left to cool and then COD was measured.
The solutions contain silver nanoparticles formed by both chemical and biomass reduction methods were centrifuged at 4800 rpm for 20 minutes
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

11. - Method for using the nanoparticles as catalyst in dyes reduction
Methodology
- Method for using the nanoparticles as catalyst in dyes reduction
Dyes reduction was chosen because it is easy to indicate the color change. NaBH4 is a good reducing agent so 4 ml of M of NaBH4 was added to 2 ml of the colored waste water. Another sample was prepared by adding 4 ml of M NaBH4 to 2 ml of the colored waste water plus the addition of 0.42 g of silver nanoparticles formed by lemon leaves. 0.5 g of silver nanoparticles formed by NaBH4
Figure 5.1 Textile wastewater
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

12. 3- RESULTS AND DISCUSSIONS
Results of synthesis of silver nanoparticles
Synthesis of silver nanoparticles using lemon leaves extract
3.1.1UV- spectroscopy analysis of the solution
The highest absorbance was at wavelength of 450 nm. Silver nanoparticles from Moringa Oleifera were analyzed similarly by Prasad and Elumalai (2011).
Figure Absorbance spectrum of silver nanoparticles
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

13. 3.1.2 SEM (Scanning Electron Microscopy) analysis
RESULTS AND DISCUSSIONS
3.1.2 SEM (Scanning Electron Microscopy) analysis
Three solutions were prepared to get the most accurate and the best result of the nanoparticles.
Figure shows surface image of silver nanoparticles formed using lemon leaves. The image at scale of 1 µm shows improper formation of nanoparticles, it does not show a good structure of the surface, there are more defects and it looks like the silver nanoparticles agglomerated during the time between the formation and the analysis which was about one week and the absence of the stabilizer cause the silver nanoparticles to agglomerate and form larger particles.
Figure (A) SEM image of silver nanoparticles formed using lemon leaves
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

14. 3.1.2 B SEM (Scanning Electron Microscopy) analysis
RESULTS AND DISCUSSIONS
3.1.2 B SEM (Scanning Electron Microscopy) analysis
Figure B represents SEM images for the second sample. The sample was diluted and sonicated. Sonication is the act of applying sound energy to the particles to crush it as mechanical process (Wikipedia, 2013). So the results of the sample ware rejected because of the presence of other process in the formation of silver nanoparticles which is not a part of the formation method in this project.
Figure B SEM image of silver nanoparticles prepared using lemon leaves and sonication process
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

15. 3.1.2 SEM (Scanning Electron Microscopy) analysis
RESULTS AND DISCUSSIONS
3.1.2 SEM (Scanning Electron Microscopy) analysis C D
Figures (C & D ) SEM image of silver nanoparticles prepared using lemon leaves and sonication process
The images indicate well dispersed particles having a uniform nanostructure.
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

16. 3.1.3 TEM (Transmission Electron Microscopy) analysis
RESULTS AND DISCUSSIONS
3.1.3 TEM (Transmission Electron Microscopy) analysis
Figures 3.2.0A and B show the nanoparticles which was formed. It confirmed that there is a formation of nanoparticles but the images shows also agglomerated nanoparticles and this is due to the high tendency of silver nanoparticles to agglomerate in the absence of the stabilizer.
Figures (A, B) TEM images of silver nanoparticles formed using lemon leaves extract
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

17. 3.1.3 TEM (Transmission Electron Microscopy) analysis
RESULTS AND DISCUSSIONS
3.1.3 TEM (Transmission Electron Microscopy) analysis
Figure C shows the spherical shape and the crystalline structure of the formed nanoparticles. The image at scale of 50 nm and the size of the formed nanoparticles varies between 12 nm – 36 nm.
Figure C TEM image of silver nanoparticles formed using lemon leaves extract
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

18. RESULTS AND DISCUSSIONS
3.2.0 Results of the synthesis of silver nanoparticles using the chemical reducing agent (NaBH4)
After 40 minutes of the reaction the color of the solution has changed from light white color to yellow color, this confirmed that the reaction was preceded correctly. It does not ensure the reduction of silver ions to silver nanoparticles but it indicates that there is a reduction. However the instrument analysis will show the reduction results. Figure 3.2.0
Figure solution of silver nanoparticles
solution from the reduction using NaBH4
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

19. 3.2.1 UV- visible spectroscopy analysis of the solution
RESULTS AND DISCUSSIONS
3.2.1 UV- visible spectroscopy analysis of the solution
The reduction can be easily notified using UV-Spectroscopy because of the Plasmon resonance of silver nanoparticles. The spectrum graph shows a peak at 395 nm when the calibration was set from 350 nm to 510 nm with a resolution of 1 nm. Figure 3.2.1
Figure UV-Visible spectrum of silver nanoparticles formed using NaBH4
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

20. 3.2.2 SEM (Scanning Electron Microscopy) analysis
RESULTS AND DISCUSSIONS
3.2.2 SEM (Scanning Electron Microscopy) analysis
Figures shows a shiny surface of the resulted nanoparticles, the shiny surface exists due to the presence of the small sizes of silver nanoparticles which has a Plasmon resonance. A similar image was reported by Kamyar, et al., (2012).
Figures SEM images of silver nanoparticles formed by chemical reduction
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

21. RESULTS AND DISCUSSIONS
3.2.3 TEM ( Transmission Electron Microscopy) analysis of the formed nanoparticles using Nabh4 A B
Figure A shows the agglomerated nanoparticles but it shows also the particles were formed in large numbers. Figure B represent the very small nanoparticles formed the scale of 200 nm shows tiny and small nanoparticles which can be in less than 18 nm in size.
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

22. RESULTS AND DISCUSSIONS
3.2.3 TEM analysis C
Figure C shows the spherical shape of the formed nanoparticles in different sizes within the range of 18 nm - 59 nm with the present of the small nanoparticles indicated in the pervious figures. It also shows the crystalline structure of the nanoparticles forms and some of the irregular shape formed beside the spherical shape.
Figure C TEM image of the silver nanoparticles formed using chemical reduction
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

23. AgNO3+NaBH4 → Ag + ½ H2 + ½ B2H6+ NaNO3
RESULTS AND DISCUSSIONS
The previous results and analysis confirmed the formation of the nanoparticles using lemon leaves which reduced the silver ions to nanostructure in 2 hours and 30 minutes. The reduction to silver nanoparticles occurred because of the presence of – C –O groups of polyols in lemon leaves. – C –O groups like the flavones, terpenoids and polysaccharides are the responsible of the reduction in the lemon leaves (Padma, 2012).
And the reduction of silver ions to silver nanoparticles using NaBH4 can be represented by this equation:
AgNO3+NaBH4 → Ag + ½ H2 + ½ B2H6+ NaNO3
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

24. 3.3.0 Results and Discussion of the applications of nanoparticles formed
3.3.1 Reduction of COD in textile waste water using Silver nanoparticles
COD of the textile wastewater before the addition of silver nanoparticles was 682 mg/L. COD concentration after the addition of silver nanoparticles was studied for 4 days. Table 3.3.1A shows the value of COD for four days after adding 0.52g of silver nanoparticles formed using lemon leaves.
Days
First day
Second day
Third day
Fourth day
COD after adding Ag-NP in mg/L
482.8
150.8
120.7
120.5
Reduction %
29.2%
68.76%
19.4%
0.16%
Table A COD values after the addition of silver nanoparticles formed by lemon leaves
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

25. 3.3.1 Reduction of COD in textile waste water using Silver nanoparticles
Days
First day
Second day
Third day
Fourth day
COD after adding Ag-NP in mg/L
479.3
365.8
280.7
278.6
Reduction percentage
29.7%
23.68%
23.26%
0.49%
Table B COD values after the addition of silver nanoparticles formed using NaBH4
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

26. COD of textile waste water (150.8 mg/L)
3.3.1 Reduction of COD in textile waste water using Silver nanoparticles
How ?!
COD of textile waste water (682 mg/L)
COD reduction can be explained as the ability of silver nanoparticles to contribute in nitrification process which is the removal of organic nitrogen from waste water and since nitrogen is organic matters it contributes in increasing COD value so the formed silver nanoparticles proved its ability in the reduction of COD concentration.
Silver nanoparticles (using lemon leaves reduction)
COD of textile waste water
(150.8 mg/L)
68.76%
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

27. 3.3.1 Reduction of COD in textile waste water using Silver nanoparticles
From the results in table 3.3.1A it is clear that the formed nanoparticles which have spherical shape and of the size between 12nm – 36 nm reduced the COD concentration which confirm them ability in contributing in textile wastewater treatment.
Table B shows that nanoparticles formed using NaBH4 was less effective in the first and second days than those which formed using lemon leaves and this can happened because the formed nanoparticles using lemon leaves 12nm-36 nm were smaller in size than the formed nanoparticles using NaBH nm.
The percentage of the reduction decreases in the third and fourth days, this can be due to many reasons like; the tendency of silver nanoparticles to agglomerate and form bigger particles which reduces its surface area and as a result its COD reduction efficiency. Another reason can be explained here is that silver nanoparticles deactivated because of the contaminated organics on its surface
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

28. 3.4.0 Silver nanoparticles as a catalyst in dyes reduction
The formed nanoparticles were studied for industrial application as a catalyst for dyes reduction from textile waste water. Dyes reduction was chosen because it is easy to note the change in the color of the water.
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

29. 3.4.0 Silver nanoparticles as a catalyst in dyes reductionB A
Figure (A) textile wastewater (B) textile wastewater after adding NaBH4 (C) textile wastewater after adding Ag-NP formed by lemon leaves (D) textile wastewater after adding Ag-NP formed by NaBH4
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

30. 3.4.0 Silver nanoparticles as a catalyst in dyes reduction
There is a clear change in the color which can be easily noted by the naked eye and this prove the ability of the formed nanoparticles to speed up the reaction because in figure B the color reduction was very slight even it can not be noted but after the addition of silver nanoparticles during the same period of time the reduction in color was highly notable.
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

31. 4.4.0 Conclusion
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London

32. 5.5.0 Recommendation / Future Work
1- The formed nanoparticles can be studied for more applications like the removal of heavy metals from wastewater and the antibacterial activity for biological treatment in wastewater.
2- Different biomasses can be studied further for the reduction of silver nanoparticles.
3- It is recommended to study the factors which can affect the size and the shape of silver nanoparticles.
4-If it is possible to get silver from waste like from used x-ray films and then reduce it to silver nanoparticles it will be environmental effective but this process takes a long time.
IJAS International Conference in Engineering and Technology, 7-9 Dec 2017, University of London