Enabling photocatalytic hydrogen production over Fe-based MOFs by refining band structure with dye sensitization

Abstract

Fe-based metal-organic frameworks (MOFs) have shown promising applications in photocatalysis, yet they are incapable of photocatalytic H2 production due to their inappropriate conduction band (CB) position and large overpotential for H2 evolution. Herein, we present a facile strategy enabling the photocatalytic H2 production over Fe-based MOFs through dye sensitization. A combination of characterization techniques with theoretical simulation reveals that dye sensitization can effectively inject energetic electrons into Fe-MOFs and elevate their quasi-Fermi level under light irradiation, overcoming the surface overpotential for H2 production from water. Furthermore, deposition of Pt nanoparticles on Fe-MOFs can lower the overpotential for H2 evolution toward further enhanced photocatalytic activity. This work provides insights into MOF band structure engineering at electronic level, and proves a concept that harnesses MOF materials for targeted photocatalytic applications they are originally not fit for.