Effect of Doping Transition Metal Ions on Photocatalysis of TiO2 Nanowires

2012 ◽  
Vol 217-219 ◽  
pp. 203-206 ◽  
Author(s):  
Yu Ming Tian ◽  
Yuan Yuan Zhao ◽  
Chang Wei Gong ◽  
Yue Sheng Chai
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Metal Ions ◽  
Visible Region ◽  
Methyl Orange Solution ◽  
Transition Metal Ions ◽  
Nanowire Arrays ◽  
Oxygen Absorption ◽  
Doping Content ◽  
Photocatalytic Activities

In order to restrain the recombination of electron-hole pairs of photocatalysis and induce the absorption spectra to shift to the visible region, TiO2nanowire arrays doped with different transition metal ions were prepared by sol-electrophoresis deposition method. The photocatalytic activities of all doped nanowire arrays (M/TiO2) were measured under visible light. Transition metal ions (Fe3+, Zn2+, Cr3+and Cu2+) were chosen as doping ions. The best doping content of each ion was found via photocatalytic degradation of methyl orange solution under visible light, there are 0.5 wt% Fe3+，1.0 wt% Zn2+，0.5 wt% Cr3+and 0.25 wt% Cu2+respectively. Under the best doping content of each ion for M/TiO2nano-arrays, the photocatalytic activities are Fe>Zn>Cu>Cr. The effect mechanisms are discussed from different views of doped semiconductor and surface oxygen absorption.

scholarly journals The Effect of Transition Metal Doping on the Photooxidation Process of Titania-Clay Composites

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Judit Ménesi ◽  
Renáta Kékesi ◽  
László Kőrösi ◽  
Volker Zöllmer ◽  
André Richardt ◽  
...  
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Metal Ions ◽  
Copper Ions ◽  
Reference Sample ◽  
Transition Metal Ions ◽  
Ethanol Vapor ◽  
Light Sources ◽  
Kinetics Of ◽  
Uv C

Montmorillonite- composites containing various transition metal ions (silver, copper, or nickel) were prepared, and their photocatalytic efficiencies were tested in the degradation of ethanol vapor at 70% relative humidity. Two light sources, UV-rich ( = 254 nm) and visible ( = 435 nm), were used. The kinetics of degradation was monitored by gas chromatography. It was established that, in the case of each catalyst, ethanol degradation was more efficient in UV-C ( = 254 nm) than in visible light, furthermore, these samples containing silver or copper ions were in each case about twice more efficient than P25 (Degussa AG.) used as a reference. In photooxidation by visible light, /clay samples doped with silver or copper were also more efficient than the reference sample, P25 . We show that doping metal ions can also be delivered to the surface of the support by ion exchange and significantly alters the optical characteristics of the /clay composite.

Comparison of photocatalytic activities of 3d transition metal ions for hydrogen peroxide photolysis and photoinitiated hydroxylation of 2-hydroxybenzoic acid

1987 ◽  
Vol 52 (10) ◽  
pp. 2451-2456 ◽  
Author(s):  
Petr Sedlák ◽  
Stanislav Luňák ◽  
Pavel Lederer
Keyword(s):  
Hydrogen Peroxide ◽  
Photocatalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
The Other ◽  
Radical Formation ◽  
Quantum Yields ◽  
Hydroxybenzoic Acid ◽  
Photocatalytic Activities

Quantum yields of hydrogen peroxide photolysis and photoinitiated hydroxylation of 2-hydroxybenzoic acid in the presence of 3d transition metal ions have been measured. Marked photocatalytic effects were only observed for Cu(II) in hydrogen peroxide photolysis, and for Fe(III) in photoinitiated hydroxylation of 2-hydroxybenzoic acid. No photocatalytic activity was detected for the other 3d transition metal ions investigated. Fe(III) and Cu(II) differ in their photocatalytic activities, suggesting that the simple concept of free OH. radical formation cannot explain the mechanisms of their action.

The electrochemical properties, nitrogen adsorption, and photocatalytic activities of three 3D metal–organic frameworks bearing the rigid terphenyl tetracarboxylates ligands

CrystEngComm ◽  
2016 ◽  
Vol 18 (17) ◽  
pp. 3086-3094 ◽  
Author(s):  
Bao Mu ◽  
Chang-Xia Li ◽  
Ming Song ◽  
Yan-Li Ren ◽  
Ru-Dan Huang
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Electrochemical Properties ◽  
Metal Organic Frameworks ◽  
Nitrogen Adsorption ◽  
Transition Metal Ions ◽  
Photocatalytic Activities ◽  
Metal Organic

Three new 3D complexes derived from the rigid terphenyl tetracarboxylates ligands with different transition metal ions have been successfully prepared. In addition, the title complexes exhibit different properties.

scholarly journals Study of Photocatalytic Activity and Properties of Transition Metal Ions Doped Nanocrystalline TiO2Prepared by Sol-Gel Method

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
K. S. Siddhapara ◽  
D. V. Shah
Keyword(s):  
Photocatalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Uv Light ◽  
Sol Gel ◽  
Visible Region ◽  
Transition Metal Ions ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method

Transition metal (Mn, Fe, Co,) doped TiO2nanoparticles were synthesized by the sol-gel method. All the prepared samples were calcined at different temperatures like 200°C to 800°C and characterized by X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis. The studies revealed that transition metal (TM) doped nanoparticles have smaller crystalline size and higher surface area than pure TiO2. Dopant ions in the TiO2structure caused significant absorption shift into the visible region. The results of photodegradation of formaldehyde in aqueous medium under UV light showed that photocatalytic activity of TiO2nanoparticles was significantly enhanced by the presence of some transition metal ions. Chemical oxygen demand (COD) of formaldehyde solutions done at regular intervals gave a good idea about mineralization of formaldehyde.

Photocatalytic activity of transition-metal-ion-doped coordination polymer (CP): photoresponse region extension and quantum yields enhancement via doping of transition metal ions into the framework of CPs

2014 ◽  
Vol 43 (23) ◽  
pp. 8805-8813 ◽  
Author(s):  
Xin-Xin Xu ◽  
Zhong-Ping Cui ◽  
Xin Gao ◽  
Xiao-Xia Liu
Keyword(s):  
Photocatalytic Activity ◽  
Coordination Polymer ◽  
Transition Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Transition Metal Ions ◽  
Quantum Yields ◽  
Transition Metal Ion ◽  
Photocatalytic Activities

To enhance the photocatalytic activity of CP1, TMI/CP1 were synthesized and their photocatalytic activities were studied.

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

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