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
Structural and spectroscopic study of Fe-doped TiO2 nanoparticles prepared by sol–gel method
N. H. S. Nasralla,M. Yeganeh,Yayuk Astuti,Sunthon Piticharoenphun,Nasser Shahtahmasebi,Ahmad Kompany,Masoud Karimipour,Budhika G. Mendis,N. R. J. Poolton,Lidija Šiller +9 more
TL;DR: In this paper, X-ray Photoemission Spectroscopy (XPS) of the TiO 2 :Fe nanoparticles was performed to study the electronic structure of the nanoparticles.
Journal ArticleDOI
Mono- and bi-metallic plasmonic photocatalysts for degradation of organic compounds under UV and visible light irradiation
TL;DR: Titania powders were surface modified with gold and/or silver nanoparticles (NPs) by photodeposition method as mentioned in this paper, and gold modified titania exhibited much higher photocatalytic activity during methanol dehydrogenation under UV irradiation than titania modified with monometallic silver and bimetallic Au-Ag NPs.
Journal ArticleDOI
Preparation, characterization and photocatalytic activity of TiO2 codoped with yttrium and nitrogen
TL;DR: In this paper, Nanocrystalline photocatalysts of TiO2 codoped with yttrium and nitrogen were prepared by the sol-gel method and investigated by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), the Brunauer-Emmett-Teller (BET) surface area measurement, XPS, and ultraviolet-visible diffuse reflectance spectrograph (UV-vis DRS), respectively.
Journal ArticleDOI
Plasmonic Janus‐Composite Photocatalyst Comprising Au and C–TiO2 for Enhanced Aerobic Oxidation over a Broad Visible‐Light Range
Lequan Liu,Thang Duy Dao,Thang Duy Dao,Rajesh Kodiyath,Qing Kang,Hideki Abe,Hideki Abe,Tadaaki Nagao,Tadaaki Nagao,Jinhua Ye,Jinhua Ye +10 more
TL;DR: Asymmetric Janus nanostructures containing a gold nanocage (NC) and a carbon-titania hybrid nanocrystal (AuNC/(C-TiO 2 )) are prepared using a novel and facile microemulsion-based approach that involves the assistance of ethanol.
Journal ArticleDOI
Adsorption properties of pristine and Co-doped TiO2(1 0 1) toward dissolved gas analysis in transformer oil
TL;DR: In this paper, the authors theoretically studied the adsorption of dissolved gases H2, C2H2, and C 2H4 in transformer oil and in pristine and Co-doped TiO2(1.0.1) on the basis of density functional theory calculations.
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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