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.