Synergistic effect of homogeneously dispersed Pt nanoparticles on the surface of self-sensitized porphyrin metal–organic frameworks for effective photocatalytic H2 evolution

Recently, there has been significant interest in the investigation of high-efficiency photocatalysts utilizing metal–organic frameworks (MOFs). The combination of metal nanoparticles (MNPs) into MOFs to form composites, such as platinum NPs (PtNPs)/MOFs, has become a prevalent and widely employed method in the field of photocatalysis. In this investigation, a simple method was employed to distribute PtNPs uniformly across the surface of a self-sensitized palladium porphyrin MOF (PCN-222(Pd)). When subjected to irradiation by visible light, the hybrid material 3%Pt/PCN-222(Pd) demonstrated a notably effective rate of 3932 μmol g -1 h - 1 photocatalytic H 2 generation from the water, which is 2.2 times greater than a single PCN-222(Pd). This improvement may be related to the coordination of polyvinylpyrrolidone (PVP) between C=O and Zr 4+ , which enhances the interaction of PtNPs with PCN-222(Pd) nanorods. Consequently, the long-life electrons from Pd-metalized tetrakis(4-carboxyphenyl)porphyrin (PdTCPP) photosensitizers rapidly shift towards the electron capture site of PtNPs, significantly reducing the occurrence of recombination between photogenerated electron-hole pairs. The utilization of the synergistic effect of Pd-porphyrin photosensitizers and PtNPs co-catalyst in this technique efficiently enhances electron transport between Pd-porphyrin and PtNPs units, hence promoting the rate of H 2 evolution.