Au-TiO2/SiO2 photocatalysts with NOx depolluting activity: Influence of gold particle size and loading

This paper analyses the possibility of obtaining surface-infused nano gold particles with the polyether ether ketone (PEEK) using picosecond laser treatment. To fuse particles into polymer, the raw surface of PEEK was sputtered with 99.99% Au and micromachined by an A-355 laser device for gold particle size reduction. Biomimetic pattern and parameters optimization were key properties of the design for biomedical application. The structures were investigated by employing surface topography in the presence of micron and sub-micron features. The energy of the laser beam stating the presence of polymer bond thermalisation with remelting due to high temperature was also taken into the account. The process was suited to avoid intensive surface modification that could compromise the mechanical properties of fragile cardiovascular devices. The initial material analysis was conducted by power–depth dependence using confocal microscopy. The evaluation of gold particle size reduction was performed with scanning electron microscopy (SEM), secondary electron (SE) and quadrant backscatter electron detector (QBSD) and energy dispersive spectroscopy (EDS) analysis. The visibility of the constituted coating was checked by a commercial grade X-ray that is commonly used in hospitals. Attempts to reduce deposited gold coating to the size of Au nanoparticles (Au NPs) and to fuse them into the groove using a laser beam have been successfully completed. The relationship between the laser power and the characteristics of the particles remaining in the laser irradiation area has been established. A significant increase in quantity was achieved using laser power with a minimum power of 15 mW. The obtained results allowed for the continuation of the pilot study for augmented research and material properties analysis.

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Supported Au catalysts for propene total oxidation: Study of support morphology and gold particle size effects

Catalysis Today ◽

10.1016/j.cattod.2011.07.009 ◽

2011 ◽

Vol 176 (1) ◽

pp. 7-13 ◽

Cited By ~ 23

Author(s):

M. Ousmane ◽

L.F. Liotta ◽

G. Pantaleo ◽

A.M. Venezia ◽

G. Di Carlo ◽

...

Keyword(s):

Particle Size ◽

Gold Particle ◽

Size Effects ◽

Total Oxidation ◽

Particle Size Effects ◽

Oxidation Study ◽

Gold Particle Size

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Supported gold cluster catalysts prepared by solid grinding using a non-volatile organogold complex for low-temperature CO oxidation and the effect of potassium on gold particle size

Applied Catalysis B Environmental ◽

10.1016/j.apcatb.2018.09.053 ◽

2019 ◽

Vol 241 ◽

pp. 539-547 ◽

Cited By ~ 9

Author(s):

Luong Xuan Dien ◽

Tamao Ishida ◽

Ayako Taketoshi ◽

Duc Q. Truong ◽

Huynh Dang Chinh ◽

...

Keyword(s):

Particle Size ◽

Low Temperature ◽

Co Oxidation ◽

Gold Particle ◽

Gold Cluster ◽

Gold Particle Size ◽

Low Temperature Co Oxidation ◽

Supported Gold

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Gold Particle Size Determination on Au/TiO2-CeO2 Catalysts by Means of Carbon Monoxide, Hydrogen Chemisorption and Transmission Electron Microscopy

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.5.13 ◽

2009 ◽

Vol 5 ◽

pp. 13-23 ◽

Cited By ~ 12

Author(s):

C. Guzmán ◽

Gloria Del Angel ◽

Ricardo Gómez ◽

F. Galindo ◽

R. Zanella ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Carbon Monoxide ◽

Particle Size ◽

Gold Particle ◽

Precipitation Method ◽

Hydrogen Chemisorption ◽

Gold Particles ◽

Transmission Electron ◽

Gold Particle Size

Au/TiO2 and Au/TiO2-CeO2 catalysts were prepared by the sol-gel method and carbon monoxide, hydrogen chemisorption and TEM spectroscopy have been exploited to determine the size of gold particles. The gold nanoparticles (8.1 to 2.1 nm) were deposited by using the deposition-precipitation method. The XRD characterization shows the presence of anatase as the TiO2 crystalline phase; while by XPS spectroscopy, the presence of Au°, Au2O3, Ce3+ and Ce4+ species co-existing in the Au/TiO2-CeO2 catalysts is shown. The characterizations by TPD-CO as well as by TPD-H2 (temperature programmed desorption) showed that on catalysts containing cerium, the gold particle size can be determined with great accuracy by using these chemisorption methods. The gold particle size calculated from either the CO or H2 thermodesorption values is in good agreement with that obtained by High Resolution Transmission Electron Microscopy (HRTEM) and Scanning Transmission Electron Microscopy (STEM) analyses. It was proposed that the TPD-CO and/or TPD-H2 techniques could be helpful for the characterization of the gold particles by TEM; especially when the high contrast in the pictures of the supports containing CeO2 prevents the particle size from being determined.

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Effective diameters of protein A-gold and goat anti-rabbit-gold conjugates visualized by field emission scanning electron microscopy.

Journal of Histochemistry & Cytochemistry ◽

10.1177/40.6.1588022 ◽

1992 ◽

Vol 40 (6) ◽

pp. 751-758 ◽

Cited By ~ 8

Author(s):

P Lea ◽

D K Gross

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Particle Size ◽

Field Emission ◽

Gold Particle ◽

Protein A ◽

Gold Complexes ◽

Gold Particles ◽

Gold Particle Size ◽

Scanning Electron

High-voltage (15-30 kV) field emission scanning electron microscopy (FESEM) was used to evaluate the effects of gold particle size and protein concentration on the formation of protein-gold complexes. Six colloidal gold sols were prepared, ranging in diameter from 7.6 to 39.8 nm. The minimal protecting amounts (m.p.a.) of protein A and goat anti-rabbit antibody (GAR) were experimentally determined. Gold particles were conjugated at the m.p.a., one half the m.p.a., and ten times the m.p.a. for both proteins, and protein-gold complexes prepared for FESEM. The smallest colloidal gold particles required the most protein per milliliter of gold suspension for stabilization. Transmission electron microscopy was found to be the preferred method for accurate sizing of gold particles, whereas FESEM of protein-gold complexes permitted visualization of a protein halo around a spherical gold core. Protein halo width varied significantly with changes in gold particle size. Measurements of protein halos indicated that conjugation with the m.p.a. of protein A resulted in the thickest protein layers for all gold sizes. GAR conjugation with the m.p.a. again produced the thickest protein layers. However, GAR halos were significantly smaller than those obtained with protein A conjugation. The proteins used showed similar adsorption patterns for the larger gold particles. For smaller gold particles, proteins may act differently, and these complexes should be further characterized by low-voltage FESEM.

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