Surface-Grafted Single-Atomic Pt-N_x Complex with a Precisely Regulating Coordination Sphere for Efficient Electron...

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) like NH2-MIL-125 are promising photocatalysts.
• Efficient charge separation is crucial for improving photocatalytic activity.
• Controlling the coordination environment of single-atom catalysts is key to tuning reactivity.

Purpose of the Study:

• To develop a novel MOF-molecule hybrid catalyst for enhanced photocatalytic hydrogen evolution.
• To investigate the effect of platinum single-atom coordination on catalytic performance.
• To elucidate the mechanism of photoinduced charge migration.

Main Methods:

• Post-modification of NH2-MIL-125 with Pt(bpy)Cl2 via amide reaction.
• Further functionalization to precisely control Pt single-atom coordination (PtN2 and PtN4).
• Characterization of material properties and photocatalytic hydrogen evolution activity measurement.

Main Results:

• The Pt(bpy)Cl2 modification redirected charge migration to PtNx, enhancing electron transfer and separation.
• The NML-PtN2 catalyst achieved a hydrogen evolution rate of 7.608 mmol g-1 h-1, significantly outperforming pristine MOF and NML-PtN4.
• High apparent quantum yield (4.01%) and turnover frequency (190.3 h-1) demonstrate efficient solar energy utilization.

Conclusions:

• Precisely regulating the Pt single-atom coordination sphere is critical for optimizing MOF-based photocatalysts.
• The developed MOF-molecule catalyst offers a new strategy for efficient charge carrier separation.
• This work provides profound insights for designing advanced single-atom catalysts for energy applications.