Solar-driven production of highly concentrated hydrogen peroxide by Zn3In2S6/PCN-222 heterostructure

The key to storage of solar energy is to obtain highly concentrated hydrogen peroxide (H2O2). However, achieving the versatility of reaction, separation and collection in a one-step process is a great challenge. Herein, a Zn3In2S6/porphyrin-based porous coordination network (Zn3In2S6/PCN-222, abbreviated as ZIS/PCN) heterojunction with strong electron/energy transfer was prepared for H2O2 production and organic synthesis in a two-phase system. Interestingly, Zn3In2S6 regulated the hydrophilicity/hydrophobicity of PCN-222, enhanced oxygen adsorption and optimized the reaction system. Thus, hydrophobic ZIS/PCN photocatalysts were selectively dispersed in the organic phase, while the generated H2O2 existed in the aqueous phase, achiveing the spontaneous seperation and collection of H2O2. The results showed that the H2O2 production (302 mM) in ZIS/PCN systems was 1.7 and 107.7 times higher than that in PCN-222 and Zn3In2S6 systems, respectively, and 7.7 times higher than reported MOF-based photocatalysts in similar systems. This work widens the application of heterojunction engineering in H2O2 photoproduction.