Porphyrin-Based Metal-Organic Frameworks for Efficient Photocatalytic H2 Production under Visible-Light Irradiation

Metal-organic frameworks (MOFs) are important photocatalytic materials for H-2 production. To clarify the structure-function relationship and improve the photocatalytic activity, herein we explored a series of porphyrin-based zirconium MOFs (PCN-H-2/Pt-x:y, where x:y = 4:1, 3:2, 2:3, and 0:1) containing different ratios of H2TCPP and (PtTCPP)-T-II [TCPP = tetrakis(4-carboxyphenyl)porphyrinate] as isostructural ligands and Zr-6 clusters as nodes. Under visible-light irradiation, PCN-H-2/Pt-0:1 shows the highest average H-2 evolution reaction rate (351.08 mu mol h(-1) g(-1)), which decreases along with lowering of the ratio of PtIITCPP in the PCN-H-2/Pt-x:y series. The differences in photocatalytic activity are attributed to more uniformly dispersed Pt2+ ions in PCN-H-2/Pt-0:1, which promotes charge transfer from porphyrins (photosensitizers) to Pt-II ions (catalytic centers), leading to efficient charge separation in the MOF materials. The bifunctional MOFs with photosensitizers and catalytic centers provide new insight for the design and application of porphyrin-based photocatalytic systems for visible-light-driven H-2 production.

Automated summary

A series of porphyrin-based zirconium MOFs were explored for photocatalytic H-2 production, with MOF containing more uniformly dispersed Pt2+ ions showing the highest H-2 evolution reaction rate under visible-light irradiation. The differences in photocatalytic activity were attributed to efficient charge transfer from photosensitizers to catalytic centers in MOF materials.