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
More filters
Journal ArticleDOI
Photocatalytic degradation of methylene blue on CaBi6O10/Bi2O3 composites under visible light
TL;DR: In this article, the photocatalytic activity of the CaBiO composites was evaluated through the decomposition of methylene blue in an aqueous solution under visible light irradiation (> 420nm).
Journal ArticleDOI
Efficient photocatalytic degradation of brilliant green using Sr-doped TiO2 nanoparticles
TL;DR: Strontium doped TiO 2 nanoparticles have been successfully synthesized by an ultrasonic-hydrothermal method and post calcination treatments as discussed by the authors, and the synthesized catalyst has been characterized in details using X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer Emmett-Teller (BET) surface area analyzer, thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), XPS (X-ray photoelectron spectroscopy) and photoluminescence (
Journal ArticleDOI
Recyclable UV and visible light photocatalytically active amorphous TiO2 doped with M (III) ions (M = Cr and Fe)
TL;DR: In this paper, a modified impregnation method was used to obtain amorphous TiO 2 doped with Cr(III) and Fe(III), designated as Cr-TiO 2 and Fe-Ti O 2, respectively, and the resulting products were characterized by X-ray diffraction, scanning electron microscopy, specific surface area by the Brunauer, Emmett and Teller method, UV-vis absorption and diffuse reflectance spectroscopy, and electron spin resonance analysis.
Journal ArticleDOI
Synthesis and characterization of samarium and nitrogen doped TiO2 photocatalysts for photo-degradation of 4-acetamidophenol in combination with hydrodynamic and acoustic cavitation
Sunil Rajoriya,Swapnil Bargole,Suja George,Virendra Kumar Saharan,Parag R. Gogate,Aniruddha B. Pandit +5 more
TL;DR: In this paper, samarium (Sm) and nitrogen (N) doped TiO2 photocatalysts have been synthesized using conventional sol-gel process (CSP) and ultrasound assisted solgel process.
Journal ArticleDOI
Visible-light photoactivity of nitrogen-doped TiO2 : Photo-oxidation of HCO2H to CO2 and H2O
TL;DR: In this paper, Nitrogen-doped TiO_2 powders were found to be active for the degradation of formic acid under visible light and the catalytic efficiency was tested by monitoring the photocatalytic degradation of CO 2 and H 2O under visible-light irradiation.
References
More filters
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.
Related Papers (5)
Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides
Electrochemical Photolysis of Water at a Semiconductor Electrode
Akira Fujishima,Kenichi Honda +1 more