scholarly journals Colloidal Metal Oxide Nanoparticles Prepared by Laser Ablation Technique and Their Antibacterial Test

2019 ◽  
Vol 3 (1) ◽  
pp. 25 ◽  
Author(s):  
Johan Duque ◽  
Brayan Madrigal ◽  
Henry Riascos ◽  
Yenny Avila
Keyword(s):  
Surface Plasmon Resonance ◽  
Laser Ablation ◽  
Metal Oxide ◽  
Band Gap ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Ablation Technique ◽  
532 Nm ◽  
Absorbance Spectra ◽  
Laser Ablation Technique

In this article we report the production of metal oxide (TiFe2O4, ZnFe2O4) nanoparticles by pulsed laser ablation technique in a liquid environment. We used nanosecond Nd: YAG laser systems working at 532 nm and 1064 nm of wavelength and the energy of the laser beam was kept constant at 80 mJ. Absorbance spectra, surface plasmon resonance, optical band-gap, and nanoparticle morphology were investigated using ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Changing the wavelength of the laser for growth, nanoparticles showed shift between the absorbance and surface plasmon resonance peaks in their UV-Vis spectra, which implies that the optical properties of the colloid nanoparticles depend on laser parameters. This was confirmed with the variation of the band gap energy. Furthermore, redshift for the absorbance peak was observed for samples as-grown at 532 nm around 150 nm as a function of time preparation. Conversely, for the samples as-grown at 1064 nm there was no shift in the absorbance spectra, which could be due to agglomeration and formation of larger particles. The characterization results showed appropriate plasmonic photo-catalysts properties of the particles, hence the photoactivation of the nanoparticles was examined on antibacterial effect using colonies of Staphylococcus aureus and Escherichia coli.

scholarly journals Colloidal Metal Oxide Nanoparticles Prepared by Laser Ablation Technique and Their Antibacterial Test

2019 ◽  
Author(s):  
Johan Duque ◽  
Brayan Moreno ◽  
Yenny Avila ◽  
Henry Riascos
Keyword(s):  
Surface Plasmon Resonance ◽  
Laser Ablation ◽  
Metal Oxide ◽  
Band Gap ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Ablation Technique ◽  
532 Nm ◽  
Absorbance Spectra ◽  
Laser Ablation Technique

We report the production of metal oxide (TiFe2O4, ZnFe2O4) nanoparticles by pulsed laser ablation technique in liquid environment. We used nano second Nd: YAG   laser systems working at 532 nm and 1064 nm of wavelength, the energy of the laser beam was kept constant at 80 mJ. Absorbance spectra, surface plasmon resonance, optical band-gap and nanoparticle morphology were investigated using ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Changing the wavelength of the laser for growth, nanoparticles shown shift between the absorbance and surface plasmon resonance peaks in their UV-Vis spectra, this implies that the optical properties of the colloid nanoparticles depends on laser parameters, this was confirmed with the variation of the band gap energy. Furthermore, red shift for the absorbance peak was observed for samples as-growth at 532 nm around the 150 nm as function of time preparation. Whereas, for the samples as-growth at 1064 nm there is no shift in the absorbance spectra, this can be due to agglomeration and formation of larger particles. The characterization results shown appropriate plasmonic photo-catalysts properties of the particles, hence the photo activation of the nanoparticles was examined on antibacterial effect using colonies of Staphylococcus Aureus and Escherichia coli.

scholarly journals Hydrogen-Free Diamond Like Carbon Films with Embedded Cu Nanoparticles: Structure, Composition and Reverse Saturable Absorption Effect

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 760
Author(s):  
Meškinis ◽  
Vasiliauskas ◽  
Viskontas ◽  
Andrulevičius ◽  
Guobienė ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Carbon Films ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Diamond Like Carbon ◽  
Optical Absorbance ◽  
Wide Range ◽  
Absorbance Spectra

In the present research, hydrogen-free diamond like carbon films with embedded copper nanoparticles (DLC:Cu) were grown by simultaneous DC magnetron sputtering of the graphite and copper targets. X-ray photoelectron spectroscopy was used to define the composition of the samples. Atomic force microscopy studies of diamond, like carbon films containing different amount of copper, revealed wide range of the surface morphologies as well as sizes and shapes of the embedded copper nanoclusters. Raman scattering spectra of all the DLC:Cu films investigated were typical for diamond-like carbon (including samples containing more than 60 at.% of copper). sp3/sp2 carbon bond ratio in the films decreased with the increase of the Cu amount in the films. According to the optical absorbance measurements, the surface plasmon resonance related absorption peak of DLC:Cu films was only detected in the films containing 28.45 at.% Cu. For the diamond like carbon films containing more than 40 at.% Cu, a further increase of Cu amount in the nanocomposite resulted in minor changes of the absorbance spectra. Some correlation between the changes of the samples surface morphology as well as phase structure and optical absorbance spectra of the films was found. In all cases, reverse-saturable absorption of the DLC:Cu films was observed. For some DLC:Cu films damage of the sample occurred at higher light fluences that can be related to the heating that is caused by the surface plasmon resonance effect.

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