Synthesis of MgO₂-silica nanocomposite for high performance of MgO₂ nanoparticles

Application potentials of solid peroxides as an alternative to H₂O₂ are greatly limited by low peroxide content, weak reactivity, burst ROS release, and other side effects like significant pH shift and toxicity. Fabrication of peroxide nanocomposites has been a strategic approach to these problems, still suffering from a lack of the functional matrixes which enable not only solid peroxides to be stably dispersed but also their side effects to be minimized. Although silicate matrixes offer highly porous rigid networks along with substantial buffering capacity, their high affinity to metal cations hardly allowed as-syntheses of peroxide nanocomposites. This study focuses on fabrication of MgO₂-silica nanocomposites via a coprecipitation route employing partial hydroxylation of peroxide precursors. Partially hydroxylated Mg cations led to successful embedding of Mg(OH)₂ nanoparticles within silicate networks which allowed the subsequently peroxidated MgO₂ nanoparticles in a size of a few nanometers to be highly dispersed. MgO₂-silica nanocomposite evolved higher concentrations of dissolved H₂O₂ and O₂ compared to bulk MgO₂ nanoparticles. Furthermore, the embedded MgO₂ nanoparticles were completely activated in water to release all of their affordable reactive oxygen species, which was not achieved with bulk MgO₂. Therefore, it is evident that the as-syntheses of MgO₂-silica nanocomposites would lead to a remarkable advance and expansion in the applications of solid peroxides.