Effect of silver on the phase transition and wettability of titanium oxide films

Abstract

The effect of silver on the phase transition and microstructure of titanium oxide films grown by pulsed cathodic arc had been investigated by XRD, SEM and Raman spectroscopy. Following successive thermal annealing up to 1000 °C, microstructural analysis of annealed Ag-TiO2 films reveals that the incorporation of Ag nanoparticles strongly affects the transition temperature from the initial metastable amorphous phase to anatase and stable rutile phase. An increase of silver content into TiO2 matrix inhibits the amorphous to anatase phase transition, raising its temperature boundary and, simultaneously reduces the transition temperature to promote rutile structure at lower value of 600 °C. The results are interpreted in terms of the steric effects produced by agglomeration of Ag atoms into larger clusters following annealing which hinders diffusion of Ti and O ions for anatase formation and constrains the volume available for the anatase lattice, thus disrupting its structure to form rutile phase. The effect of silver on the optical and wetting properties of TiO2 was evaluated to demonstrate its improved photocatalytic performance.

Optical and Chromaticity Properties of Metal-Dielectric Composite-Based Multilayer Thin-Film Structures Prepared by RF Magnetron Sputtering

“…The Low-E coatings are typically structured as metal-dielectric multilayer thin films, which are designed to prevent heat leakage (from the inside of buildings into the environment) by providing strong and very wide-band reflection of thermal infrared wavelengths.In recent years, the optical properties of metal-dielectric coatings and their influence on building energy efficiency have been studied extensively due to their superior performance compared to other multilayer coating structure types. The metal-dielectric coatings performance mainly depends on the choice of materials and its design philosophy [7][8][9][10][11][12][13][14][15]. Most (or practically all) products available today from this category (featuring high spectral selectivity) employ at least two silver (Ag) layers within their structure, and these coatings cannot withstand prolonged (weeks-scale) exposure to either the ambient atmospheric air or dry-heat test temperatures in excess of 160-180 • C. However, the stability problems of ultrathin Ag layers (normally of less than 20 nm thickness) originate from a range of factors related to the metal layer growth morphology.…”

“…Most (or practically all) products available today from this category (featuring high spectral selectivity) employ at least two silver (Ag) layers within their structure, and these coatings cannot withstand prolonged (weeks-scale) exposure to either the ambient atmospheric air or dry-heat test temperatures in excess of 160-180 • C. However, the stability problems of ultrathin Ag layers (normally of less than 20 nm thickness) originate from a range of factors related to the metal layer growth morphology. To overcome these issues, a significant number of research works have been proposed, conducted, and resulted in reporting various solutions, where some of them require more complex materials processing and process parameters optimization [10][11][12][13][14][15][16][17][18][19]. Several reports have been published about the properties of various metal-dielectric composite (MDC) thin-film layer chemistries, including Ag + SiO 2 , Ag + TiO 2 , and Ag + MgF 2 ; however, most of them were about metal-dielectric nanoparticle array properties of interest for various applications [20][21][22][23].…”

Wash-stable, oxidation resistant conductive cotton electrodes for wearable electronics

“…The characteristic spin-orbit separation of 6.0 eV conrmed that the peaks arose from bulk metallic silver. 25,26 Deconvolution of these Ag 3d peaks provided insight into the presence of oxidized silver species. Aer exposure to air, silver-coated cotton exhibited new Ag 3d 5/2 peaks at 367.8 eV (Fig.…”

Optical and Chromaticity Properties of Metal-Dielectric Composite-Based Multilayer Thin-Film Structures Prepared by RF Magnetron Sputtering

“…In recent years, the optical properties of metal-dielectric coatings and their influence on building energy efficiency have been studied extensively due to their superior performance compared to other multilayer coating structure types. The metal-dielectric coatings performance mainly depends on the choice of materials, and its design philosophy [6][7][8][9][10][11][12][13][14]. Most (or practically all) products available today from this category (featuring high spectral selectivity and high LSG) employ at least two silver (Ag) layers within their structure, and these coatings cannot withstand prolonged (weeks-scale) exposure to either the ambient atmospheric air or dry-heat test temperatures in excess of 160-180 °C.…”

“…However, the stability problems of ultrathin Ag layers (normally of less than 20 nm thickness) originate from a range of factors related to the metal layer growth morphology. To overcome these issues, a significant number of research works have been proposed, conducted, and resulted in reporting various solutions, where some of them require more complex materials processing and process parameters optimization [9][10][11][12][13][14][15][16][17][18]. Several reports have been published about the properties of various MDC thinfilm layer chemistries, including Ag+SiO2, Ag+TiO2, and Ag+MgF2, however, most of them were about metal-dielectric nanoparticle array properties of interest for various applications [19][20][21][22].…”