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
A Simple Sol−Gel Processing for the Development of High-Temperature Stable Photoactive Anatase Titania
Sibu C. Padmanabhan,Suresh C. Pillai,John Colreavy,Sivakumar Balakrishnan,Declan E. McCormack,Tatiana S. Perova,Yurii K. Gun'ko,Steven J. Hinder,John M. Kelly +8 more
TL;DR: A method for the preparation of anatase TiO2, which is stable to a temperature as high as 900 °C, without using any complex cationic dopants is presented in this article.
Journal ArticleDOI
Effect of C content and calcination temperature on the photocatalytic activity of C-doped TiO2 catalyst
TL;DR: In this paper, the effect of carbon content and calcination temperature on the photocatalytic properties of a C-doped TiO 2 catalyst prepared by a sol-gel method was systematically investigated.
Journal ArticleDOI
Advanced chemical compositions and nanoarchitectures of bismuth based complex oxides for solar photocatalytic application
Songmei Sun,Wenzhong Wang +1 more
TL;DR: In this paper, a comprehensive overview on the fundamentals and recent advances of BiVO4, Bi2WO6 and Bi2MoO6 photocatalysts is presented, including morphology control, surface modification, doping and construction of composite material.
Journal ArticleDOI
Effect of inorganic ions in heterogeneous photocatalysis of TCE
Robert A. Burns,John C. Crittenden,David W. Hand,Volker H. Selzer,Lawrence L. Sutter,Salman R. Salman +5 more
TL;DR: In this article, the influence of 12 ionic compounds (Na2SO4, NaHCO3, Na2HPO4 and NaNO3) on performance of a fixed-bed photocatalytic reactor was examined.
Journal ArticleDOI
Ease synthesis of mesoporous WO3-TiO2 nanocomposites with enhanced photocatalytic performance for photodegradation of herbicide imazapyr under visible light and UV illumination
Adel A. Ismail,Ibrahim Abdelfattah,Ahmed Helal,Saleh A. Al-Sayari,Lars Robben,Detlef W. Bahnemann +5 more
TL;DR: The 3% WO3-TiO2 nanocomposite is considered to be the optimum photocatalyst which is able to degrade completely (100% conversion) of imazapyr herbicide along 120min with high photonic efficiency ∼8%.
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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