Electrolytic control of hydrogen peroxide release from calcium peroxide in aqueous solution

摘要

The in situ generation of hydrogen peroxide (H2O2) for water treatment is more practical than the use of liquid H2O2, which is costly to store and transport. Calcium peroxide (CaO2), a solid carrier of H2O2, can release H2O2 on dissolution in water. However, the constant H2O2 release rate of CaO2 has been a bottleneck constraining its wider application. In this study, a practical electrochemical method using a divided cell is developed to control the rate of release of H2O2 from CaO2. The results show that the rate of H2O₂ release from CaO₂ is enhanced in the anolyte. The increase in H₂O₂ release is positively correlated with the current. Under a current of 100 mA, the H₂O₂ concentration was 2.5 times higher after 30 min of electrolysis than in the control experiment in which no current was applied. Water electrolysis in the anodic compartment generates protons that not only: (i) en-hance dissolution of CaO₂ and release of H₂O₂, but also (ii) neutralize the alkaline pH resulting from CaO₂ dissolution, thus providing new advantages for the use of CaO₂. This effective technique may be suitable for the sophisticated control of H₂O₂ release in environmental applications.