Optical properties of synthesized Au/Ag Nanoparticles using 532 nm and 1064 nm pulsed laser ablation: effect of solution concentration

Abstract

The primary objective of this experimental research is to introduce the capacity of laser irradiation into the synthesis of bimetallic nanoparticles from noble metals. Gold and silver nanoparticles are produced through the laser ablating gold and silver targets in distilled water. Originally, the samples are synthesized by using Nd:YAG laser with 1064 nm wavelength and 7 ns pulse width. Following this, solutions mixed with different volumetric ratios, are irradiated by the second harmonic of the said laser at 532 nm wavelength. The absorption peak of gold nanoparticles around 530 nm, is used to transfer the laser energy to nanoparticles and synthesize Au/Ag bimetallic nanoparticles. The wavelength and volumetric ratio of solutions are the experiment's variables. The bimetallic nanoparticles are characterized as follows: X-ray diffraction pattern, spectroscopy in the range of UV–Vis-NIR and IR, Photoluminescence spectrum, Dynamic light scattering, and Fourier transform infrared spectroscopy. Additionally, FE-SEM and TEM images are used to study the size and morphology of nanoparticles. One of the aims of the research is to investigate the effects of laser wavelength and different volumetric concentrations on the optical properties of Au/Ag bimetallic nanoparticles. On the other hand, the study revealed that silver concentration and laser wavelength in the synthesis of Au/Ag bimetallic nanoparticles with different structures, cause the formation of crystalline structure, growth of grain size, and therefore silver oxide reduction.

Formation of Agshell/Aucore Bimetallic Nanoparticles by Pulsed Laser Ablation and Chemical Reduction Methods: The Effect Green Laser Wavelength and Colloidal/Solution Concentration

“…Only in the area greater than 400 nm can reveal the peaks related to the bipolar mode. Similar values have been found in similar studies [42,81]. The dipole three plasmon absorption bands detected in the VIS range are shown as s3-s5 (420 nm, 423 nm and 438 nm).…”

“…The PL spectrum which is detected near of 528-533 nm ( ~ 2.34-2.32 eV) is also recorded by R. Zakaria et al, for Au and Ag nano-owers around 535 nm (2.31 eV) [32]. In another study, similar peaks were found in the 530-540 nm ( ~ 2.33-2.29 eV) for the Au/Ag bimetallic structure [42]. The interface interaction between Au and AgNPs in PL analysis is observed as a redshift, which represents the interference in terms of LSPR of Au and AgNPs in the bimetallic system.…”

“…In the search carried out by Ayman et.al., the selected pulse uence is greater than our parameter [51]. In addition, in our current study with the pulse uency about 0.5 J/cm2 and applies only one method (PLAL) to the synthesis of the bimetallic system, can form BNPs with various structures (alloy and coreshell) and sizes [42].…”

“…Photochemical method [21], plane wave pseudopotential method [22], replacement reaction method [23], catalytic reduction [24], spray pyrolysis [25], wet-chemical method [7], chemical reduction [26,27], green synthesize [28][29][30], post-modi cation [31], electron beam deposition [32], ion implantation [33,34], electrochemical reduction [35], solid state dewetting (SSD) [36,37], pulse laser deposition (PLD) [38] and PLAL [39][40][41][42].…”

Fabrication of Au–Ag Bimetallic Nanoparticles Using Pulsed Laser Ablation for Medical Applications: A Review

“…It is worth noting that they studied the effect of laser energy simultaneously with the effect of the medium. In the study conducted by Adib Amini et al [34], solutions with varying volumetric ratios were exposed to the second harmonic of the laser at a wavelength of 532 nm. This laser-induced synthesis process led to the formation of Au-Ag bimetallic nanoparticles.…”