Synthesis of Ce-Doped MIL-125-NH2 for Promoting Catalytic H2O2 Production from Water and O2 under Visible Light Irradiation

Despite the direct utilizing metal-organic frameworks (MOFs) as promising photocatalysts for H2O2 production, their activity and selectivity are still undesirable owing to the insufficient active centers, weak visible-light absorption, and limited charge transfer. Herein, the Ce-doped Ti-based MOFs MIL-125-NH2 photocatalysts (Ce/TiMOFs) were synthesized by a facile impregnation-coordination method, during which the doped Ce species could not only extend the visible-light absorption edge but also provide new reactive sites for promoting the charge transfer and selectivity of two-electron O-2 reduction. Interestingly, the optimal Ce/TiMOFs-0.010 achieved a rate of H2O2 yield of 2464 mu M h(-1) g(-1) with similar to 3.4-fold improvement compared to TiMOFs, attributed to the faster conversion rate of the main reactive oxygen intermediates (O-center dot(2)-) and improved average transfer electron number. This work provides an effective strategy to optimize the photocatalytic performances of MOFs and expands the application of MOFs in the sustainable energy production field.