Journal ArticleDOI
The Role of Metal Ion Dopants in Quantum-Sized TiO2: Correlation between Photoreactivity and Charge Carrier Recombination Dynamics
TLDR
In this article, the presence of metal ion dopants in the TiO_2 crystalline matrix significantly influences photoreactivity, charge carrier recombination rates, and interfacial electron-transfer rates.Abstract:
A systematic study of metal ion doping in quantum (Q)-sized (2-4 nm) TiO_2 colloids is performed by measuring their photoreactivities and the transient charge carrier recombination dynamics. The presence of metal ion dopants in the TiO_2 crystalline matrix significantly influences photoreactivity, charge carrier recombination rates, and interfacial electron-transfer rates. The photoreactivities of 21 metal ion-doped colloids are quantified in terms of both the conduction band electron reduction of an electron acceptor (CCl_4 dechlorination) and the valence band hole oxidation of an electron donor (CHCl_3 degradation). Doping with Fe^(3+), Mo^(5+), Ru^(3+), Os^(3+), Re^(5+), V^(4+), and Rh^(3+) at 0.1-0.5 at.% significantly increases the photoreactivity for both oxidation and reduction while Co^(3+) and Al^(3+) doping decreases the photoreactivity. The transient absorption signals upon laser flash photolysis (λ_(ex) = 355 nm) at λ = 600 nm are extended up to 50 ms for Fe^(3+)-, V^(4+)-, Mo^(5+)-, and Ru^(3+)-doped TiO_2 while the undoped Q-sized TiO_2 shows a complete "blue electron" signal decay within 200 μs. Co^(3+)- and Al^(3+)-doped TiO_2 are characterized by rapid signal decays with a complete loss of absorption signals within 5 μs. The quantum yields obtained during CW photolyses are quantitatively correlated with the measured transient absorption signals of the charge carriers. Photoreactivities
are shown to increase with the relative concentration of trapped charge carriers. The photoreactivity of doped TiO_2 appears to be a complex function of the dopant concentration, the energy level of dopants within the TiO_2 lattice, their d electronic configuration, the distribution of dopants, the electron donor concentration, and the light intensity.read more
Citations
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Journal ArticleDOI
Photocatalytic degradation of methylene blue dye using Fe2O3/TiO2 nanoparticles prepared by sol–gel method
TL;DR: In this article, the photocatalytic degradation of methylene blue dye was successfully carried under UV irradiation over Fe 2 O 3 /TiO 2 nanoparticles embedded various composition.
Journal ArticleDOI
Photocatalytic reaction and degradation of methylene blue on TiO2 nano-sized particles
TL;DR: In this article, a self-made laboratory photocatalytic reactor and the properties of TiO2 nanoparticles are studied by using UV-A light and photodegradation of methylene blue as a water pollutant evaluated until the photocatalyst process optimizes with the process parameters.
Journal ArticleDOI
Synthesis, structure and photocatalytic properties of Fe(III)-doped TiO2 prepared from TiCl3
Zoltán Ambrus,Nándor Balázs,Tünde Alapi,Gyula Wittmann,Pál Sipos,András Dombi,Károly Mogyorósi +6 more
TL;DR: In this paper, an iron-doped titanium dioxide photocatalyst was prepared from aqueous titanium(III) chloride solution in the presence of dissolved FeCl3 by co-precipitation method.
Journal ArticleDOI
Comparative investigation on photocatalytic hydrogen evolution over Cu-, Pd-, and Au-loaded mesoporous TiO2 photocatalysts
TL;DR: In this article, the photocatalytic activity for hydrogen evolution from water using methanol as hole scavenger was comparatively investigated over mesoporous TiO2 photocatalyst with various contents of Cu, Pd, and Au cocatalyst loadings prepared by single-step sol-gel (SSSG) process with surfactant template.
Journal ArticleDOI
Visible light-activated N-F-codoped TiO2 nanoparticles for the photocatalytic degradation of microcystin-LR in water ☆
TL;DR: In this paper, a non-metal-doped TiO2 nanoparticles (N-F-TiO2) was developed by a novel synthesis route employing a simple sol-gel method containing a nonionic fluorosurfactant as pore template material to tailor-design the structural properties of TiO 2 and fluorine dopant as well as ethylenediamine as nitrogen source for the photocatalytic response towards visible light.
References
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Book
Inorganic Chemistry: Principles of Structure and Reactivity
TL;DR: In this article, inorganic chemistry principles of structure and reactivity are presented. But, they do not cover how to use these principles in the design of products, and they are not available in any type of product.
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Transition Metal Oxides: An Introduction to Their Electronic Structure and Properties
TL;DR: In this article, the authors present a chemical aspects structural principles of electronic classification and models of electronic structure: ionic models cluster models band theory intermediate models, point-defects and semiconduction, electronic carrier properties.
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