Efficient Schottky Junction Construction in Metal-Organic Frameworks for Boosting H₂ Production Activity

Area of Science:

• Materials Science
• Photocatalysis
• Nanotechnology

Background:

• Co-catalyst manipulation is crucial for enhancing metal-organic framework (MOF)-based photocatalysts.
• Controlling co-catalyst related charge transfer and activation parameters remains a significant challenge.

Purpose of the Study:

• To propose and investigate key parameters governing co-catalyst function in MOF photocatalysis: electron transfer rate (V_transfer), electron transfer distance (D_transfer), and electron consumption rate (V_consume).
• To enhance photocatalytic activity by rationally designing and manipulating the co-catalyst on UiO-66-NH2.

Main Methods:

• Compositional design: Forming PtPd alloy co-catalysts by substituting Pt with Pd.
• Location control: Encapsulating PtPd alloy within UiO-66-NH2 crystals.
• Facet selection: Exposing specific (100) facets of the encapsulated PtPd alloy.
• Characterization: Ultrafast transient absorption spectroscopy and first-principles simulations.

Main Results:

• The engineered PtPd (100)@UiO-66-NH2 Schottky junction demonstrated superior V_transfer and V_consume compared to traditional Pt/UiO-66-NH2.
• Enhanced electron-hole separation and improved H2O activation were observed in the modified photocatalyst.
• Significant enhancement in overall photoactivity was achieved.

Conclusions:

• Rational manipulation of co-catalyst composition, location, and facet exposure offers effective control over charge transfer dynamics.
• The proposed parameters (V_transfer, D_transfer, V_consume) provide a framework for understanding and optimizing MOF-based photocatalysts.
• The developed PtPd (100)@UiO-66-NH2 system represents a highly efficient photocatalyst for relevant applications.