Robust Heterogeneous Photocatalyst for Visible-Light-Driven Hydrogen Evolution Promotion: Immobilization of a Fluorescein Dye-Encapsulated Metal–Organic Cage on TiO2
| Autor: | Jian-Feng Huang, Xin-Lun Chen, Chao-Ping Hou, Shao-Yong Li, Zhi-Jian Huang, Li-Min Xiao, Jun-Min Liu, Yang Lei |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | ACS Applied Materials & Interfaces. 13:57230-57240 |
| ISSN: | 1944-8252 1944-8244 |
| Popis: | The design of artificial photocatalytic devices that simulates the ingenious and efficient photosynthetic systems in nature is promising. Herein, a metal-organic cage [Pd6(NPyCzPF)12]12+ (MOC-PC6) integrating 12 organic ligands NPyCzBP and 6 Pd2+ catalytic centers is designed, which is well defined to include organic dye fluorescein (FL) for constructing a supramolecular photochemical molecular device (SPMD) FL@MOC-PC6. Photoinduced electron transfer (PET) between MOC-PC6 and the encapsulated FL has been observed by steady-state and time-resolved emission spectroscopy. FL@MOC-PC6 is successfully heterogenized with TiO2 by a facile sol-gel method to achieve a robust heterogeneous FL@MOC-PC6-TiO2. The close proximity between the Pd2+ catalytic site and FL included in the cage enables PET from the photoexcited FL to Pd2+ sites through a powerful intramolecular pathway. The photocatalytic hydrogen production assessments of the optimized 4 wt % FL@MOC-PC6-TiO2 demonstrate an initial H2 production rate of 2402 μmol g-1 h-1 and a turnover number of 4356 within 40 h, enhanced by 15-fold over that of a homogeneous FL@MOC-PC6. The effect of the MOC content on photocatalytic H2 evolution (PHE) is investigated and the inefficient comparison systems, such as MOC-PC6, MOC-PC6-TiO2, FL-sensitized MOC-PC6/FL-TiO2, and analogue FL/MOC-PC6-TiO2 with free FL, are evaluated. This study provides a creative and distinctive approach for the design and preparation of novel heterogeneous SPMD catalysts based on MOCs. |
| Databáze: | OpenAIRE |
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