Synergy Effect of Photoabsorption due to Band-gap Excitation and Surface Plasmon Resonance on Selective Photocatalytic Oxidation of Alcohols to Ketones and Aldehydes over Silver-deposited Silver Iodide

2015 ◽  
Vol 44 (4) ◽  
pp. 518-520 ◽  
Author(s):  
Yuri Nishino ◽  
Atsuhiro Tanaka ◽  
Keiji Hashimoto ◽  
Hiroshi Kominami
Keyword(s):  
Surface Plasmon Resonance ◽  
Band Gap ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Silver Iodide ◽  
Photocatalytic Oxidation ◽  
Synergy Effect ◽  
Oxidation Of Alcohols

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.

EXCITATION COUPLING OF Au/ZnO BAND-GAP ENERGY FOR ENHANCING THE PERFORMANCE OF SURFACE PLASMON RESONANCE BIOSENSOR

2013 ◽  
Vol 25 (03) ◽  
pp. 1350055 ◽  
Author(s):  
Nan-Fu Chiu ◽  
Chii-Wann Lin
Keyword(s):  
Surface Plasmon Resonance ◽  
Band Gap ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
High Performance ◽  
Band Gap Energy ◽  
Biomolecular Detection ◽  
Interface Surface ◽  
Au Thin Films ◽  
Novel Design

This paper reports a novel design of a surface plasmon resonance (SPR) device that can be developed into a high-performance biosensor. The design utilizes wurtzite crystal structure semiconductor (zinc oxide, ZnO) layers to enhance the SPR signal quality and to improve the full width at half maximum (FWHM) of the SPR reflectivity curve. There exists a new mechanism when the excitation in the plasmon energy is in resonance with the ZnO band-gap (BG) energy transfer process. The excitation energy between Au and ZnO causes an interactive, coupled phenomenon with the ZnO BG (λBG = 360–430 nm, 3.1–3.4 eV) when it matches the ZnO–Au interface surface plasmon (400 nm). We have optimized the design of the ZnO and Au thin films thicknesses through analytical comparisons with conventional SPR structures. Upon exposure to ethanol, the ZnO–Au device showed a 2-times decrease in the FWHM and a 4.5-times larger shift in intensity interrogation. The ZnO–Au device exhibits a wider linearity range and very higher sensitivity. This characteristic of the ZnO–Au device is the basis for realizing accurate and specific biomolecular detection.

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