Two‐Phase System Utilizing Hydrophobic Metal–Organic Frameworks (MOFs) for Photocatalytic Synthesis of Hydrogen Peroxide

Much effort has been devoted to photocatalytic production of hydrogen peroxide (H₂ O₂ ) as an alternative to fossil fuels. From an economic point of view, reductive synthesis of H₂ O₂ from O₂ coupled with the oxidative synthesis of value-added products is particularly interesting. We herein report application of MIL-125-NH₂ , a photoactive metal-organic framework (MOF), to a benzylalcohol/water two-phase system that realized photocatalytic production and spontaneous separation of H₂ O₂ and benzaldehyde. Hydrophobization of the MOF enabled its separation from the aqueous phase. This resulted in enhanced photocatalytic efficiency and enabled application of various aqueous solutions including extremely low pH solution which is favorable for H₂ O₂ production but fatal to MOF structure. In addition, a highly concentrated H₂ O₂ solution was obtained by simply reducing the volume of the aqueous phase.