Microenvironmental Tuning in Isostructural Conjugated Metal-Organic Frameworks for Superior Photocatalytic H₂O₂...

Area of Science:

• Materials Science
• Photocatalysis
• Sustainable Chemistry

Background:

• Photocatalytic hydrogen peroxide (H2O2) generation offers a sustainable alternative to energy-intensive processes.
• Metal-organic frameworks (MOFs) are promising photocatalysts, but microenvironment tuning requires further investigation.

Purpose of the Study:

• To explore isostructural Mn- and Fe-based MOFs (Mn-Tp and Fe-Tp) as photocatalysts for H2O2 production.
• To investigate the impact of metal-ligand microenvironment modulation on photocatalytic performance.

Main Methods:

• Scalable, solvent-free mechanochemical synthesis of conjugated 3D MOFs.
• Photocatalytic evaluation of H2O2 generation under visible light.
• Mechanistic studies including theoretical calculations.

Main Results:

• Mn-Tp exhibited significantly higher H2O2 yield (10,487 µmol g⁻¹ h⁻¹), apparent quantum yield (9.94%), and solar-to-chemical efficiency (0.45%) compared to Fe-Tp.
• Identical MOF topology and morphology did not guarantee similar performance.
• Subtle microenvironment differences modulated electronic structure and H2O2 generation pathways.

Conclusions:

• Local redox tuning in MOFs is crucial for enhancing photocatalytic activity.
• The study provides a blueprint for designing advanced MOF catalysts for sustainable oxidant production.
• Optimized metal-node microenvironments promote efficient dual-channel H2O2 generation and suppress decomposition.