Yields of Hydrogen Peroxide in the Decomposition of Water by Cobalt γ-Radiation: II. Effect of Chloride Ion

1955 ◽  
Vol 2 (1) ◽  
pp. 26 ◽  
Author(s):  
Thomas J. Sworski
1971 ◽  
Vol 49 (24) ◽  
pp. 4005-4016 ◽  
Author(s):  
C. E. Burchill ◽  
P. W. Jones

The reactions with H2O2 of free radicals derived from 2-propanol, methanol, dimethoxymethane, and tetrahydrofuran have been investigated by e.s.r. using in-cavity photolysis with acetone photosensitization to generate the radicals in flowing aqueous solutions. The variation in the concentrations of the radicals derived from a particular solute with addition of H2O2 is attributed to the selective oxidation of one radical by H2O2, propagating a secondary chain reaction, e.g.,[Formula: see text]The rate constant for the oxidation of the acetone ketyl radical ((CH3)2ĊOH) by H2O2 is estimated to be 5 × 105 M−1 s−1.The results and conclusions of this study are demonstrated to be consistent with the results of previous investigations employing γ-radiation, photolysis, and the reaction of Ti(III) with H2O2 for initiation.Results are also reported for the direct photolysis of aqueous malonic acid in the presence of H2O2.


2017 ◽  
Vol 41 (1) ◽  
pp. 29-36
Author(s):  
Md Rezwan Miah ◽  
Tarannuma Ferdous Manny ◽  
Debashis Sen ◽  
Md Azizur Rahman ◽  
Md Saiful Alam ◽  
...  

In situ chemisorbed hydroxyl ion (OH-) onto clean polycrystalline gold (Au (poly)) electrode showed an extraordinary enhanced electrocatalytic activity towards oxidation of hydrogen peroxide anion (HO2-) in alkaline media. The oxidation of HO2- at the fabricated electrode was found to be a diffusion controlled process. The anodic transfer coefficient of the oxidation reaction was estimated as 0.47. Chloride ion (Cl-) replaced the chemisorbed OH- from the surface of the modified Au (poly) (OH-)Au (poly)) electrode leading to diminishing the observed electrocatalytic activity. The optimized concentration of KOH solution for the highest catalytic activity was found to be ca. 0.1 M. A linear calibration curve for various concentrations of HO2-? in the range of 0.5 to 5 mM was obtained having sensitivity equal to 1.028 A cm-2 M-1.Journal of Bangladesh Academy of Sciences, Vol. 41, No. 1, 29-36, 2017


1969 ◽  
Vol 47 (20) ◽  
pp. 3737-3744 ◽  
Author(s):  
W. A. Armstrong

In an attempt to clarify the reactions of ferrous sulfate and titanous sulfate with hydrogen peroxide, a novel method has been developed to determine the relative rate constants for reactions of the oxidizing species generated in these systems. These species react with hydrogen peroxide to give perhydroxyl radicals which combine with titanium(IV) ions to form the relatively stable TiOO•3+ radical. This radical gives a strong electron spin resonance signal and the competition between hydrogen peroxide and a scavenger for the oxidizing species can be followed by measuring the amplitude of this signal in the presence of various concentrations of scavenger. The relative rate constants calculated in this way for both the Fe(II)–H2O2 and Ti(III)–H2O2 systems at pH 1.0 agree with those reported for the reactions of hydroxyl radicals in γ-irradiated thymine solutions. This supports the view that hydroxyl radicals are formed in these cases.Under conditions of acidity favoring the hydrolysis of Fe(II) to FeOH+ ions, hydroxyl radical scavengers do not compete with hydrogen peroxide for the precursors of the TiOO•3+ radical. It is suggested that the FeOH+ ions react with hydrogen peroxide to give a different oxidizing species, possibly the ferryl ion.Scavengers investigated were thymine, methanol, ethanol, formic acid, acetic acid, chloride ion, and several amino acids.


2000 ◽  
Vol 267 (19) ◽  
pp. 5858-5864 ◽  
Author(s):  
Paul G. Furtmüller ◽  
Christian Obinger ◽  
Yuchiong Hsuanyu ◽  
H. Brian Dunford

2019 ◽  
Vol 21 (34) ◽  
pp. 18636-18651 ◽  
Author(s):  
Mark-Robert Kalus ◽  
Riskyanti Lanyumba ◽  
Nerea Lorenzo-Parodi ◽  
Maik A. Jochmann ◽  
Klaus Kerpen ◽  
...  

The decomposition of water and the formation of molecular hydrogen, oxygen, and hydrogen peroxide during laser ablation of redox-active materials is systematically studied and related to the ablation rate and oxidation degree of the nanoparticles.


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