SYNTHESIS AND ZETA POTENTIAL OF NOBLE METALS (Pt,Au,Ag

Sci.Int.(Lahore),28(5),4371-4375,2016

ISSN 1013-5316;CODEN: SINTE 8

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SYNTHESIS AND ZETA POTENTIAL OF NOBLE METALS (Pt,Au,Ag AND Cu)NANOPARTICLES PREPARED BY PULSE LASER ABLATION Isam M. Ibrahim1, Ahmed K. Abbas2 ,Dalya K. Naser3 1

University of Bagdad, College of Science, Department of Physics, [email protected] . University of Wasit, College of Science, Department of Physics, [email protected] . 3 University of Wasit, College of Science, Department of Physics, [email protected] . 2

ABSTRACT: Noble metal nanoparticles were synthesized by pulsed laser ablation of metals plates immersed in de-ionized water (DI) . The x-ray diffraction pattern showed that the structure of noble metal NPs film is polycrystalline with preferential orientation of platinum in (202) direction, gold in (200) direction, silver in (111) direction and copper in (111) direction. Absorbance spectrum of the produced nanoparticles solution was measured by UV-Vis spectrophotometer which shows the surface plasmon resonance (SPR) and single peak of the platinum nanoparticles about 241 nm, gold nanoparticles about 525 nm, silver nanoparticles about 412 nm and copper nanoparticles about 637nm. The shape and particle size have been confirmed by TEM measurement, the average particle size of platinum is around 17 nm, narrow distribution for Au NPs that possess particle size around 2nm, average size is around 14nm for Ag NPs and average size is around 18nm for Cu NPs. Zeta potential results proved the silver nanoparticle is more stabilizing (-22.31 mV ) than other noble metal nanoparticles, while platinum nanoparticles have more aggregation than other noble metals. Keywords: Noble metal nanoparticles (NMNPs), surface Plasmon resonance (SPR), pulse laser ablation in liquid (PLAL), zeta potential (ζP).

INTRODUCTION Noble metal nanoparticles (NMNPs) have obtained plenty of attention from researchers far to their distinctive size and shape dependent optical properties[1]. Nanoparticles of platinum (Pt), gold (Au), silver (Ag) and copper (Cu) have varied applications in the fields of optics, biology, chemistry, material science and medicine. The surface Plasmon resonance (SPR) absorption of those metal NPs were dependent on their size, shape and composition[2]. Removal of material from the surface of a solid after laser irradiation is known as laser ablation. This process plays an important role for structuring and processing of materials in many areas of technology[3]. Recently, plasma assisted methods based on laser ablation and electrical discharges have become a focus of many studies [4-7] . Zeta potential (ζP) is a scientific term for electro-kinetic potential in colloidal systems, i.e., electric potential in the interfacial double layer at the location of the slipping plane versus a point in the bulk fluid away from the interface[8]. Zeta potential measurements provide an important criterion for the stability of a colloid system[9]. In this work; Pt, Au, Ag and Cu have been prepared by pules laser ablation in liquid (PLAL) technique and their characterization have been studied.

noble metals colloids were recorded by a spectrometer (type SP-8001-Metertech).The zeta potential measurement were carried out using a Zeta Plus ( Brookhaven Instruments Corporation ,USA). An aqueous suspension of noble metal nanoparticles was filtered through a 0.2 μm before measurement.

EXPERIMENTAL The experimental setup is shown schematically in Figure (1). The beam from a Nd:YAG laser (type RS BPW 21) was set in Q-switching mode of 1064 nm on the surface of a noble metals(Pt, Au, Ag, Cu) targets (99.9% in purity). The targets were fixed in a glass vessel which contains 3 ml de-ionized water. The laser pulse duration was about 10 ns, the pulserepetition rate 6 Hz, the laser power 500 mJ and 300 pulses. Thin film was obtained by spray technique in order to spray the collide liquid on a silicon substrate to obtain an uniform distributed nanoparticles thin films. The crystalline structure was examined by X-ray diffractions using (Philips PW) X-ray diffractometer system .The UV-Vis absorption spectra of

RESULTS AND DISCUSSION 1- The structural analysis Figure(2) shows the structure of Pt NPs which have a polycrystalline structure and cubic phase, there is a matching between the orientation of the Miller Indices (hkl) to each peak for Pt NPs with the JCPDS standard card No. (#96-1011112) these planes (111), (200), (202), and (311) planes that peaks at (2θ=38.7225◦, 44.9262◦,65.5940◦,and 78.8520◦), (202) direction represents the strongest peak (i.e the maximum intensity in the direction (202)). Table (1) shows structural parameters viz. Inter-planar spacing, crystallite Size(D) for the Pt NPs.

Figure (1): Experimental setup for pulse laser ablation in liquid system

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(111) (222)

Intensity (Arb. Unit)

(311) (311)

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(202)

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Figure(5) XRD spectrum of Experimental pattern of Cu NPs.

2- Absorption spectra of Pt, Au, Ag and Cu NPs Noble metals nanoparticles solution prepared in this study has a peak absorbance. As in Figures (6- 9) the characteristic plasmon resonance absorption peak was observed at 241 nm, 525nm, 412nm and 637nm for Pt, Au, Ag and Cu NPs respectively. The colors of nobel metals is one of the indications of nanoparticles formation, where the color solutions changes to brown indicating the formation of platinum nanoparticles, the color of the solution change to pink , indicating the formation of gold nanoparticles, the color of the solution change to yellow indicating the formation of silver nanoparticles and the color of the solution change to green indicating the formation of copper nanoparticles [see figure )10)]

(111)


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Figure(4) XRD spectrum of Experimental pattern of Ag NPs.

(202) (200) (111


Figure(2) XRD spectrum of Experimental pattern of Pt NPs.

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Sci.Int.(Lahore),28(5),4371-4375,2016

(111)


Figure(3) shows that Au NPs has a polycrystalline structure and cubic phase for Au NPs, there is a matching between the orientation of the Miller Indices (hkl) to each peak for Au NPs with (111), (200), (202) and (311), planes at positions (2θ=38.3600◦, 44.60◦,64.90◦,77.96◦)which have good agreement with the JCPDS standard card No. (#96-9012431). (200) direction represents the strongest peak (i.e the maximum intensity in the direction (200)). Table (2) shows structural parameters viz. Inter-planar spacing, crystallite Size for the Au NPs. Figure(4) shows that Ag NPs has a polycrystalline structure and cubic phase for Ag NPs. The peaks (111), (200) planes that peaks at (2θ=37.93◦,44.03◦ ) for Ag NPs agreement with the JCPDS standard card No. (#96-901-3049). Table (3) shows structural parameters viz. Inter-planar Spacing, crystallite size for the Ag NPs. Figure(5) shows that Cu NPs. The peaks (111),(200) planes that peaks at (2θ=42.4730◦,49.4130◦ ) for Cu NPs agreement with the JCPDS standard card No. (#96-901-3024). Table (4) shows structural parameters viz. Inter-planar spacing, crystallite size for the Cu NPs.


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35 40 45 50 55 60 65 70 75 80 2θ (Degree) Figure(3) XRD spectrum of Experimental pattern of Au NPs.

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Sci.Int.(Lahore),28(5),4371-4375,2016


Figure (6): Optical absorbance as a function of wavelength for

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Figure (9): Optical absorbance as a function of wavelength for prepared Cu NPs.

prepared Pt NPs.

Figure(10): colliadial of noble metals nanoparticle.

Figure (7): Optical absorbance as a function of wavelength for prepared Au NPs.

Figure (8): Optical absorbance as a function of wavelength for prepared Ag NPs.

3- Transmission electron microscopy (TEM) analysis for Pt, Au, Ag and Cu NPs. Figure (11-14) shows that the TEM image and size distribution of Pt, Au, Ag and Cu NPs respectively. It's clear from these images that the average platinum nanoparticles is around 17 nm, narrow distribution for Au NPs that possess particle size around 2nm, average size is around 14nm for Ag NPs and average size is around 18nm for Cu nm.

Figure (11): TEM image of Pt NPs at 500 mJ and 300 pulses

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Sci.Int.(Lahore),28(5),4371-4375,2016

4- Zeta potential of noble metals Figures (15-18) show the values of zeta potential of the prepared Pt, Au, Ag and Cu NPs at laser power 500 mJ, and 300pulses are -17.28mV, -18.79mV, -22.31mV and 21.80mV, respectively. Notes that more negativity value means more stability of NPs in the colloidal solution.

Figure(12): TEM image of Au NPs at 500 mJ and 300 pulses.

Figure(15): Zeta potential for Pt NPs.

Figure (13): TEM image of Ag NPs at 500 mJ and 300 pulses.

Figure(16): Zeta potential for Au NPs.

Figure (14): TEM image of Cu NPs at 500 mJ and 300 pulses.

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Figure (17): Zeta potential for Ag NPs.

Figure (18): Zeta potential for Cu NPs.

CONCULUSIONS Certain pure noble metals colloidal nanoparticles can be formed by laser ablation technique in de-ionized water. XRD illustrated the polycrystalline structure for the prepared noble metals NPs TEM images proved the nanosize for these noble metals NPs with spherical shape. The zeta potential results show that the colloidal of Ag NPs is the most stabilizing than other noble metals, while the colloidal of Pt NPs is the most aggregation than other noble metals.

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[3] See, E.g., M. von Allmen, and A. Blatter, Laser-Beam Interactions with Matter, vol. 2. Springer, Berlin, 1995. [4] Tarasenko, N. V., Butsen, A. V., Nevar, E. A., Savastenko, and N. A., “Synthesis of nanosized particles during laser ablation of gold in water.,” Appl. Surf. Sci., vol. 252, pp. 4439–4444, 2006. [5] Simakin, A. V., Voronov, V. V., Shafeev, G. A., Brayner, R., Bozon-Verduraz, and F, “Nanodisks of Au and Ag produced by laser ablation in liquid environment,” Chem. Phys. Lett., vol. 348, pp. 182– 186, 2001. [6] Kabashin, A. V., Meunier, M., Kingston, C., &, Luong, and J. H., “Fabrication and characterization of gold nanoparticles by femtosecond laser ablation in an aqueous solution of cyclodextrins,” J. Phys. Chem. B, vol. 107, pp. 4527–4531, 2003. [7] Parkansky, N., Alterkop, B., Boxman, R. L., Goldsmith, S., Barkay, Z., Lereah, and Y., “Pulsed discharge production of nano-and microparticles in ethanol and their characterization,” Powder Technol., vol. 150, pp. 36–41, 2005. [8] Kutscher, H. L., Chao, P., Deshmukh, M., Rajan, S. S., Singh, Y., Hu, P., ... & Sinko, and P. J., “Enhanced passive pulmonary targeting and retention of PEGylated rigid microparticles in rats,” Int. J. Pharm., vol. 402, pp. 64– 71, 2010. [9] Hunter and R. J, Zeta potential in colloid science: principles and applications., vol. 386. Academic press, 1982.

REFERENCES [1] Mafuné, F., Kohno, J. Y., Takeda, Y., Kondow, and T., “Formation of stable platinum nanoparticles by laser ablation in water.,” J. Phys. Chem. B, vol. 107, pp. 4218–4223, 2003. [2] Mendivil, M. I, S. Shaji, G. A. Castillo, and B. Krishnan, “Transmission electron microscopic studies on noble metal nanoparticles synthesized by pulsed laser ablation in liquid,” Microscopy: Advances in Scientific Research and Education, pp. 911–920, 2014.

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