Sonochemical Formation of Hydrogen Peroxide

Abstract

Abstract:The work detailed in this study utilized 20 kHz ultrasonic irradiation as a mechanism of hydrogen peroxide production. The effects of various operating parameters were investigated, including ultrasonic intensity; solution pH; source of water; initial dibutyl phthalate concentration and the presence of hydrogen peroxide. During the irradiation, the H2O2 concentration was monitored. The results indicate that H2O2 is produced by cavitation during ultrasonic irradiation. An increase in ultrasonic intensity increases the amount of hydrogen peroxide produced. The initial pH of the solution does not affect the efficiency of processes substantially. H2O2 is regarded as one of the most effective additives enhancing the sonochemical production of hydroxyl radicals and hydrogen peroxide. Above a 0.1 mM dose of H2O2, the amount of H2O2 formed decreased as the concentration of H2O2 increased. Thus, the concentration of hydrogen peroxide plays a crucial role in the extent to which the effectiveness of the combined process is enhanced. The negative effect on reactions of the presence of additional components in the reaction solution was also confirmed. It was therefore concluded that the experimental evaluation of optimum parameters of hybrid processes is a matter of importance.

Degradation of 4-Chlorophenol in Aqueous Solution by Sono-Electro-Fenton Process

“…Although studies have shown that US supports creation of H 2 O 2 especially in presence of O 2 and that O 2 can conserve • OH radicals to generate other oxidizing species like • O and OH2 [35,36], the results under the conditions tested here are in an agreement with other studies showing negative effect on H 2 O 2 formation. For example, Ziembowicz et al found that initial H 2 O 2 plays a crucial role in the effectiveness of the combined process (similar to the combined process used here) [52]. It was found that when initial concentration of H 2 O 2 increases above 0.1 mM (compared to 0.3 mM formed under tested conditions here), the amount of H 2 O 2 formed under US decreases significantly.…”

Facile fabrication of conductive MoS2 thin films by sonication in hot water and evaluation of their electrocatalytic performance in the hydrogen evolution reaction

“…Analysis of the S 2-/Mo 4+ ratios from high resolution XPS data (Table 1) demonstrates that there are no significant changes in the ratio from the bulk 2H phase to the various samples with higher films. 27,32,33 The temperature dependence and magnitude of this effect under our conditions therefore needs to be established.…”

Degradation Efficiency and Kinetics Analysis of an Advanced Oxidation Process Utilizing Ozone, Hydrogen Peroxide and Persulfate to Degrade the Dye Rhodamine B

“…The results are presented in Figure 3a. The use of hydrogen peroxide was omitted in order to minimize the risk of oxidation process inhibition by an excessive quantity of H2O2, which may result in • OH radical recombination and the auto-decomposition of H2O2 into H2O and O2, as evidenced [42][43][44]. Based on the obtained results, it was concluded that the decolorization degree depends on the initial dye concentration.…”