Well-distributed Pt-nanoparticles within confined coordination interspaces of self-sensitized porphyrin metal-organic frameworks: synergistic effect boosting highly efficient photocatalytic hydrogen evolution reaction

• Published in: Chemical science (Cambridge) 2019-12, Vol.1 (45), p.1577-1585
• Main Authors: Li, Shuai, Mei, Hong-Min, Yao, Shi-Lin, Chen, Zhi-Yao, Lu, Yu-Lin, Zhang, Li, Su, Cheng-Yong
• Format: Article
• Language: English
• Subjects: Catalytic activity; Chemical energy; Chemistry; Clusters; Coordination; Crystallography; Hydrogen evolution reactions; Light irradiation; Metal-organic frameworks; Nanoparticles; Organic chemistry; Palladium; Photocatalysis; Platinum; Solar energy conversion; Sustainable development; Synergistic effect; Transition metals
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c9sc01866b

Effective conversion of solar energy into chemical energy by visible light represents a potential strategy for sustainable development. Among which, photocatalytic hydrogen evolution reaction (HER) with a relatively small activation energy (1.23 eV, around 1000 nm light irradiation) is especially attractive. In this work, well-distributed platinum nanoparticles (Pt-NPs) with a width of about 3 nm have been successfully immobilized into the confined coordination interspaces of 3.7 nm diameter, which are facilitated by early transition metal Hf( iv )-based clusters of a self-sensitized palladium porphyrin metal-organic framework. Under visible light irradiation, the resultant Pt@Pd-PCN-222(Hf) (which is also denoted as Pt@Pd-PMOF-2(Hf)) displays superb photocatalytic activity, achieving an unprecedented maximum H 2 evolution rate of 22 674 μmol g −1 h −1 with a turn-over number (TON) of 4131.2 in 32 h and the highest turn-over frequency (TOF) of 482.5 h −1 based on Pt-NPs. This photocatalyst can be recycled and reused for three successive runs without significant loss of catalytic activity. This effective strategy takes advantage of the synergetic effect between Pd-porphyrin photosensitizers and Pt-NP co-catalysts confined within nanoscale coordination interspaces incorporating hydrophilic Hf( iv )-oxo clusters. An effective strategy for the fabrication of an efficient HER photocatalyst of Pt@Pd-PCN222(Hf) has been reported.