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.

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.

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 Effect of magnesium-salts on hydrogen peroxide bleaching of non-wood pulps

2016 ◽  
Vol 51 (4) ◽  
pp. 291-296
Author(s):  
N Das ◽  
SK Bose ◽  
D Biswas
Keyword(s):  
Hydrogen Peroxide ◽  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Peroxide Bleaching ◽  
Lower Viscosity ◽  
Pulp Viscosity ◽  
Acid Washing ◽  
Mg Addition ◽  
Wood Pulps

Transition metal ions present in pulp, cause wasteful decomposition of hydrogen peroxide, a pulp brightener, and thus significantly affect the delignification selectivity of hydrogen peroxide bleaching. The metal ions also affect the brightness and optical properties of pulp. The free radicals generated during the decomposition degrade carbohydrates resulting in lower viscosity and yield. It is reported in the literature that magnesium sulfate successfully adsorbs transition metal ions and thus decrease their activity. This study dealt with the effect of Mg salts in hydrogen peroxide bleaching of jute caddies pulp. It was observed that prior bleaching treatments like chelation and acid washing of pulp were efficient in removing transition metal ions as indicated by lower consumption of hydrogen peroxide. However EDTA chelation seemed better compared to acid washing. The inclusion of Mg salts improved pulp brightness. The pulp viscosity was the highest with 0.3% Mg addition for both treated kraft and soda-AQ pulps. Considering both pulp viscosity and pulp brightness, it appeared that a 0.3% Mg dose on EDTA chelated pulp, was enough in hydrogen peroxide bleaching of pulps obtained from jute caddies. Bangladesh J. Sci. Ind. Res. 51(4), 291-296, 2016

scholarly journals DNA Oxidative Cleavage Induced by the Novel Peptide Derivatives of 3-(quinoxalin-6-yl)alanine in Combination with Cu(II) or Fe(II) Ions

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Wojciech Szczepanik ◽  
Marzena Kucharczyk-Klamińska ◽  
Piotr Stefanowicz ◽  
Anna Staszewska ◽  
Zbigniew Szewczuk ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Stable Complex ◽  
The Novel ◽  
Complex Species ◽  
Peptide Derivatives ◽  
Derivatives Of

Three model dipeptides containing 3-(2,3-di(pyridin-2-yl)quinoxalin-6-yl)alanine, 3-(dipyrido[3,2-a:2,3-c]phenazin-11-yl)alanine, and 3-(2,3-diphenylquinoxalin-6-yl)alanine were studied with respect to their ability to bind selected transition metal ions, such as Cu(II), Fe(II), Ni(II), Co(II), Mn(II), and Cr(III). It was found that only Cu(II) and Fe(II) ions could form stable complex species with the studied compounds. The ability to form the complexes correlated well with DNA damage experiments. Only the ferrous and cupric complexes are capable of generating both single- and double-strand scissions. However, double-strand breakages appear to be dominating lesions in the presence of hydrogen peroxide, especially for copper(II) containing systems. The quantity of breakage products in the presence ofN-(3-(dipyrido[3,2-a:2,3-c]phenazine-11-yl)alanyl)glycine complexes was the highest as compared to the complexes of the remaining compounds. Moreover, this ligand was the only one that cleaved DNA in the absence of either Cu(II) or Fe(II) ions.

Effect of transition metal ions on photocatalytic activity of ZnO in bleaching of some dyes

2006 ◽  
Vol 88 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Suruchi Bhandari ◽  
Jitendra Vardia ◽  
R. K. Malkani ◽  
Suresh C. Ameta
Keyword(s):  
Photocatalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions
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