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
An investigation of trichloroethylene photocatalytic oxidation on mesoporous titania-silica aerogel catalysts
TL;DR: In this paper, mesoporous, titania-silica aerogel catalysts were used for gas phase photocatalytic oxidation of trichloroethylene (TCE) in a new photoreactor where the reactant gases flow through the aerogels block.
Journal ArticleDOI
(Sulfur, Nitrogen)-Codoped Rutile-Titanium Dioxide as a Visible-Light-Activated Photocatalyst
Hongyan Liu,Lian Gao +1 more
TL;DR: In this article, the (S,N)-codoped rutile-TiO2 photocatalyst was synthesized using a hydrothermal method and subsequent nitridation under NH3 flow.
Journal ArticleDOI
Synthesis, Characterization, Electronic Structure, and Photocatalytic Behavior of CuGaO2 and CuGa1–xFexO2 (x = 0.05, 0.10, 0.15, 0.20) Delafossites
TL;DR: The photochemical reduction of CO2 to chemicals, such as CO and CH4, is a promising carbon management approach that can generate revenue from chemical sales to help offset the costs associated with the use of carbon management technologies as mentioned in this paper.
Journal ArticleDOI
Efficient indium tin oxide/Cr-doped-TiO2 multilayer thin films for H2 production by photocatalytic water-splitting
TL;DR: In this paper, the authors showed that the photocurrent increases as function of the number of bilayers by reaching the maximum with 6-bilayers of ITO/Cr-doped-TiO2.
Journal ArticleDOI
Surface characterisation of metal ions loaded TiO2 photocatalysts: structure–activity relationship
Agatino Di Paola,Elisa I. García-López,Giuseppe Marcì,Cristina Martín,Leonardo Palmisano,Vicente Rives,Anna Maria Venezia +6 more
TL;DR: In this article, transition metal loaded TiO 2 powders were characterised and tested for the photodegradation of some organic acids, including methanoic and benzoic acid.
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.
Book
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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