Real-time investigations of structural and optical changes in photochromic Ag/TiO2 nanocomposite thin films under laser irradiation
نویسندگان
چکیده
Photochromic reaction dynamics in silver nanoparticles embedded inmesoporous titaniumdioxide thinfilms is investigated by combining real-time grazing incidence small-angle x-ray scattering (GISAXS) and optical transmissionmeasurements duringUV–visible laser exposure cycles.While GISAXS probes changes in the particle size distribution, transmittancemeasurements are sensitive to spectral changes induced by photo-activated processes. Our results reveal a repeatable photochromic behavior with a good correlation in terms of kinetics between themorphological and optical fluctuations. Visible laser irradiation at 532 nm induces a preferential photo-dissolution of small silver particles, which in turn causes an increase in transmittance near the excitationwavelength. Furthermore, the photo-dissolution process can be significantly accelerated and amplified by associating visible laser with x-ray irradiation. UnderUV laser irradiation at 360 nm, the bleaching process can be reverted by photocatalytic reductionwith themesopores in the TiO2film acting as molds, which have the ability to confine the nanoparticle growth.However, in the irradiation conditions used in the present study, it appears that the photocatalytic growth of silver nanoparticles is slower than the photo-dissolution process, whereas its efficiency gradually degrades throughout the exposures toUV light.
منابع مشابه
Microstructural and plasmonic modifications in Ag–TiO2 and Au–TiO2 nanocomposites through ion beam irradiation
The development of new fabrication techniques of plasmonic nanocomposites with specific properties is an ongoing issue in the plasmonic and nanophotonics community. In this paper we report detailed investigations on the modifications of the microstructural and plasmonic properties of metal-titania nanocomposite films induced by swift heavy ions. Au-TiO2 and Ag-TiO2 nanocomposite thin films with...
متن کاملFabrication of Nb/V co-doped TiO2 thin films and study of structural, optical and photocatalytic properties
In this study, different samples of Niobium and Vanadium co-doped titania thin films (5-10-15 mol% Nb and 5-10-15 mol% V) were prepared via sol−gel dip coating method, using niobium chloride as niobium precursor, ammonium metavanadate as vanadium precursor, and titanium (IV) butoxide (TBT) as titanium precursor. The effects of doping amount on the structural, optical, and photo-catalytic prope...
متن کاملFabrication of Nb/V co-doped TiO2 thin films and study of structural, optical and photocatalytic properties
In this study, different samples of Niobium and Vanadium co-doped titania thin films (5-10-15 mol% Nb and 5-10-15 mol% V) were prepared via sol−gel dip coating method, using niobium chloride as niobium precursor, ammonium metavanadate as vanadium precursor, and titanium (IV) butoxide (TBT) as titanium precursor. The effects of doping amount on the structural, optical, and photo-catalytic prope...
متن کاملThe Influence of Ag Doping on Structural, Optical Properties and Photocatalytic Activity of TiO2/SiO2 Nanocomposite
In the present study, TiO 2 /SiO 2 and TiO 2 /SiO 2 /Ag nanocomposite powders were synthesized by sol-gel technique. Moreover, for investigation of the Ag doping effect different concentrations of dopant were added. Structures were characterized by IR spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive Analytical X-Ray (EDAX), and X-Ray Diffraction (XRD) methods. Fur...
متن کاملEffects of Ag, Nd codoping on structural, optical and photocatalytic properties of TiO2 nanocomposite synthesized via sol-gel method using starch as a green additive
In this paper, undoped TiO2 and Ag-Nd-codoped TiO2 nanocomposites with different molar ratios of dopants were synthesized by the sol-gel method using starch as a natural additive. Structures were investigated by FT-IR and UV–Vis spectroscopy, SEM, and XRD methods. Moreover, the direct band gap was calculated by Tauc's approach. Furthermore, photocatalytic activity of all s...
متن کامل