Porphyrin-Based Metal–Organic Frameworks for Efficient Photocatalytic H2Production under Visible-Light Irradiation

Metal–organic frameworks (MOFs) are important photocatalytic materials for H2production. To clarify the structure–function relationship and improve the photocatalytic activity, herein we explored a series of porphyrin-based zirconium MOFs (PCN-H2/Ptx:y, where x:y= 4:1, 3:2, 2:3, and 0:1) containing different ratios of H2TCPP and PtIITCPP [TCPP = tetrakis(4-carboxyphenyl)porphyrinate] as isostructural ligands and Zr6clusters as nodes. Under visible-light irradiation, PCN-H2/Pt0:1shows the highest average H2evolution reaction rate (351.08 μmol h–1g–1), which decreases along with lowering of the ratio of PtIITCPP in the PCN-H2/Ptx:yseries. The differences in photocatalytic activity are attributed to more uniformly dispersed Pt2+ions in PCN-H2/Pt0:1, which promotes charge transfer from porphyrins (photosensitizers) to PtIIions (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 H2production.