Photosynthesis of H2O2 in pure water over 2D metal-organic frameworks film by co-doping Ga and porphyrin

Hydrogen peroxide (H2O2) is a clean oxidizing agent and potential energy carrier. Photocatalytic H2O2 production has garnered increased attention due to its green and energy-saving process. However, existing photocatalysts face several challenges, such as limited response to visible light, the requirement for sacrificial reagents, and complications in powder recycling. In this work, we synthesized two-dimensional (2D) NH2-MIL-53(Al) films co-modified with Ga and tetrakis (4-carboxyphenyl) porphyrin (TCPP) with enhanced photocatalytic activity of 268.7 µmol∙g−1∙h−1 from only O2 and pure H2O, reaching 3.5 times higher than pure NH2-MIL-53(Al). Notably, in comparison with other reported MOF photocatalysts, NMA-Ga5%-L30 stands out with the highest photocatalytic H2O2 generation activity in a pure water system under visible light. Moreover, this sample film was readily recovered from a photocatalytic system and exhibits significant cycling stability. The heightened photocatalytic activity is attributed to the dual modification, which not only reduces the photogenerated band gap but also promotes the charge carrier's separation and transfer. This work provides a strategy for the design of MOFs-based photocatalysts with easy recycle properties for artificial photosynthesis of H2O2.