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
Hydrothermally stabilized Fe(III) doped titania active under visible light for water splitting reaction
TL;DR: In this article, it was found that hydrothermal treatment at 110°C for 10h was essential for the synthesis of highly stabilized Fe 3+ doped TiO 2 photocatalysts.
Journal ArticleDOI
Photocatalytic CO [sub] 2 reduction : a review of ab initio mechanism, kinetics, and multiscale modeling simulations
TL;DR: In this paper, the authors search for possible ways of reducing CO2 emissions or even capturing it from the atmosphere using catalytic reduction of CO2 into value-added chemicals has been discussed.
Journal ArticleDOI
Mesoporous plasmonic Au-TiO2 nanocomposites for efficient visible-light-driven photocatalytic water reduction
Jun Fang,Shaowen Cao,Zheng Wang,Mohammad Mehdi Shahjamali,Say Chye Joachim Loo,James Barber,James Barber,Can Xue +7 more
TL;DR: In this article, the mesoporous Au-TiO 2 nanocomposites with different Au concentrations were prepared via a co-polymer assisted sol-gel method, and they exhibited remarkable visible-light activity for H 2 evolution from photocatalytic water reduction in the presence of ascorbic acid as the electron donor.
Journal ArticleDOI
One-dimensional Titanium Dioxide Nanomaterials: Nanotubes
TL;DR: In this article, a comprehensive and most up-to-date view of the field of anodic TiO2 nanotube arrays is given, with an emphasis on the currently most investigated nanotubular anodic nanotubes arrays.
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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