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
Nitrogen complex species and its chemical nature in TiO2 for visible-light sensitized photocatalysis
Ryoji Asahi,Takeshi Morikawa +1 more
TL;DR: In this article, the detailed assignment of N 1s binding energies observed in the XPS measurement was analyzed and detailed analyses of the formation energies showed that introducing the N species more in a controlled way via process conditions is crucial to achieve the optimized photocatalytic performance.
Journal ArticleDOI
Improved photocatalytic activity of Sn4+ doped TiO2 nanoparticulate films prepared by plasma-enhanced chemical vapor deposition
TL;DR: In this article, a nanoparticulate film with a doping ratio of about 7∶100 (Sn)∶(Ti) was prepared by the plasmaenhanced chemical vapor deposition (PCVD) method.
Journal ArticleDOI
Photocatalytic degradation of organic pollutants coupled with simultaneous photocatalytic H2 evolution over graphene quantum dots/Mn-N-TiO2/g-C3N4 composite catalysts: Performance and mechanism
Yu-Chun Nie,Fan Yu,Lai-Chun Wang,Qiu-Ju Xing,Xia Liu,Yong Pei,Jian-Ping Zou,Weili Dai,Yan Li,Steven L. Suib +9 more
TL;DR: In this paper, the effect of different organic pollutants on photocatalytic H2 evolution was investigated using GQDs/TCN-0.4 catalysts in the presence of simulated solar irradiation.
Journal ArticleDOI
Photocatalytic degradation of Rhodamine B dye under UV/solar light using ZnO nanopowder synthesized by solution combustion route
TL;DR: In this paper, the effect of parameters such as the crystallite size, amount of catalyst, concentration of the dye, pH and irradiation on photocatalytic degradation of rhodamine B (RB) dye was studied.
Journal ArticleDOI
Preparation of visible-light responsive N–F-codoped TiO2 photocatalyst by a sol–gel-solvothermal method
TL;DR: Anatase type N-F-codoped TiO 2 powder was successfully prepared by a sol-gel-solvothermal method using tetrabutyl titanate as precursor as discussed by the authors.
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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