Two-phase interfacial photocatalysis via amphiphilic Bi2WO6 to facilitate synchronous production and spontaneous separation of H2O2 and value-added organics

Photocatalytic synthesis of H2O2 from O2 reduction coupled with selective oxidation of organics into value-added chemicals is highly appealing; however, the troubling separation process presents a technical difficulty when both H2O2 and organic products are obtained in a homogeneous solution. Herein, an amphiphilic Bi2WO6 catalyst was synthesized through a facile solvothermal method based on the synergetic modification with both hydrophobic and hydrophilic groups, which enables the construction of Pickering emulsion interfacial photocatalysis systems in various organic/water mixtures to facilitate synchronous production and spontaneous separation of H2O2 and value-added organics. The amphiphilic Bi2WO6 catalyst exhibited significantly enhanced photocatalytic performance compared to its oleophilic and hydrophilic counterparts, resulting in remarkable generation rates of H2O2 and benzaldehyde reaching up to 121.53 and 99.25 mmol g−1h−1, respectively, in a benzyl-alcohol/water biphasic system under simulated sunlight. The excellent photocatalytic performance could be maintained in a long-term reaction process. The photocatalytic mechanism was investigated through various control experiments and detailed characterizations. The interfacial photocatalysis played a crucial role in accelerating the redox reactions, showcasing its favorable applicability in various organic/water biphasic systems. This study provides guidelines for the realization of interfacial photocatalysis assisted by amphiphilic semiconductors, opening up a novel strategy to the simultaneous production of solar fuels and organic chemicals.