Anodic Titanium Oxide Layers Modified with Gold, Silver, and Copper Nanoparticles

Abstract

Titanium(IV) oxide is commonly used in photocatalysis. However, it has some drawbacks, e.g., a high rate of electron-hole recombination and a wide bandgap. In here, the surface of anodic titanium(IV) oxide (ATO) was modified with metal nanoparticles (gold, silver, and copper) in order to enhance its photoelectrochemical (PEC) and photocatalytic (PC) properties. SEM analysis revealed that Au, Ag, and Cu nanoparticles obtained on an ATO surface by chemical methods had an average diameter of 50 ± 10 nm, 30 ± 6 nm, and 25 ± 3 nm, respectively. Enhancement of photoelectrochemical water-splitting current efficiency in the wavelength range of 300–400 nm was observed due to the occurrence of the Schottky barriers. However, the nanoparticles had no effect on the current efficiency in the range of 400–600 nm which meant that the surface plasmon resonance (SPR) effect was not observed. A rate of methyl red photodecomposition was improved after the modification of the ATO surface. The best results were obtained for ATO decorated with gold nanoparticles.

Removal of an Ethoxylated Alkylphenol by Adsorption on Zeolites and Photocatalysis with TiO2/Ag

“…A significant improvement in absorption due to surface plasmon resonance between 500 and 600 nm was achieved as shown, resulting from the interaction of the metal particles with the incident light. The improvement of the photocatalyst efficiency by the inclusion of metallic particles such as silver could be confirmed by Fermi energy levels which were displaced at values close to the bottom of the conduction band; the accumulation of electrons influences the plasmon absorption band, which can improve the photocatalytic activity of a material in the visible region [20,23] our results indicates that the bandwidth of the titanium modified with silver was 2.9 EV.…”

“…A significant improvement in absorption due to surface plasmon resonance between 500 and 600 nm was achieved as shown, resulting from the interaction of the metal particles with the incident light. The improvement of the photocatalyst efficiency by the inclusion of metallic particles such as silver could be confirmed by Fermi energy levels which were displaced at values close to the bottom of the conduction band; the accumulation of electrons influences the plasmon absorption band, which can improve the photocatalytic activity of a material in the visible region [20,23] our results indicates that the bandwidth of the titanium modified with silver was 2.9 EV. The results of X-ray diffraction (DRX), as well as the results of scanning electron microscopy (SEM) and those of the analysis of the chemical composition of the catalyst (SEM-EDS) have been published in a previous article [24]; they indicated that the actual percentage of deposited silver was 3.4% and that there was no evidence of alteration in the composition of the crystalline phase of the catalyst significantly due to the inclusion of metallic silver.…”

“…While photocatalysis has proven to be an efficient process for the removal of organic molecules, "load recombination" decreases the process efficiency [23]. In this regard, catalyst doping is an efficient means to achieve the deposition of metallic species on the surface of a catalyst in order to change its electrical properties and increase its efficiency for photocatalytic processes.…”

Antibacterial effect of TiO2:Cu:Ag thin coatings on Pseudomonas strain measured by microbiological and ATP assays

“…The significantly faster effect of this component composition of thin films as well as overcoming the resistance of the highly adaptive Pseudomonas DSM50026 can be explained by the structure of the nanocomposite films. The doping of TiO 2 with Ag and Cu nanoparticles improved the photoresponse and photocurrent density of TiO 2 into the visible light region [21][22][23]. Other authors proved the several mechanisms of action of silver [17,18] and copper nanoparticles [16,20,21,24].…”

Visible-Light Active Titanium Dioxide Nanomaterials with Bactericidal Properties

“…The modified TNTs formed on Ti-based implants can reduce bacterial colonization on their surfaces accordingly. Alternatively, antibacterial CuNPs can be used to replace AgNPs for doping TNTs with improved biocompatibility [98,99]. CuNPs are less toxic than AgNPs to human and bovine mammary epithelial cells [344].…”