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
Highly Efficient Formation of Visible Light Tunable TiO2-xNx Photocatalysts and Their Transformation at the Nanoscale
TL;DR: In this article, a simple nanoscale exclusive synthesis route was used to obtain catalytically active TiO2-xNx anatase structured particles whose absorption onset extends well into the visible region at λ ∼ 550 nm.
Journal ArticleDOI
Size dependency of nanocrystalline TiO2 on its optical property and photocatalytic reactivity exemplified by 2-chlorophenol
TL;DR: In this article, the electro-optical and photocatalytic properties of the synthesized TiO2 nanoparticles were studied along with several commercially available ultra-fine TiO 2 particles (e.g., 3.8-5.7nm).
Journal ArticleDOI
Efficient TiO2 Photocatalysts from Surface Hybridization of TiO2 Particles with Graphite-like Carbon
Liwu Zhang,Hongbo Fu,Yongfa Zhu +2 more
TL;DR: In this paper, photoelectrochemical measurements confirm an electronic interaction between TiO2 and graphite-like carbon, and the mechanism of the enhanced photocatalytic activity under UV irradiation is based on the high migration efficiency of photoinduced electrons at the graphitelike carbon/TiO2 interface.
Journal ArticleDOI
Photocatalytic purification of volatile organic compounds in indoor air: A literature review
Jinhan Mo,Yinping Zhang,Qiujian Xu,Jennifer Joaquin Lamson,Jennifer Joaquin Lamson,Rongyi Zhao +5 more
TL;DR: A review of the status of research on photocatalytic oxidation (PCO) purification of VOCs in indoor air can be found in this paper, where some recommendations are made for future work to evaluate the performance of PCO catalysts, to reduce the generation of harmful intermediates and to design new PCO reactors with integrated UV source and reaction surface.
Journal ArticleDOI
Food packaging based on polymer nanomaterials
TL;DR: In this article, the latest innovations in food packaging, using improved, active and smart nanotechnology is analyzed, and the limits to the development of the new polymer nanomaterials that have the potential to completely transform the food packaging industry.
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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