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

Metal-organic frameworks (MOFs) are important photocatalytic materials for H production. To clarify the structure-function relationship and improve the photocatalytic activity, herein we explored a series of porphyrin-based zirconium MOFs (PCN-H/Pt, where : = 4:1, 3:2, 2:3, and 0:1) containing different ratios of HTCPP and PtTCPP [TCPP = tetrakis(4-carboxyphenyl)porphyrinate] as isostructural ligands and Zr clusters as nodes. Under visible-light irradiation, PCN-H/Pt shows the highest average H evolution reaction rate (351.08 μmol h g), which decreases along with lowering of the ratio of PtTCPP in the PCN-H/Pt series. The differences in photocatalytic activity are attributed to more uniformly dispersed Pt ions in PCN-H/Pt, which promotes charge transfer from porphyrins (photosensitizers) to Pt 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 production.