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Zeolitic Imidazolate frameworks (ZIFs) have been demonstrated as promising light harvesting and photocatalytic materials for solar energy conversion. To facilitate their application in photocatalysis, it is essential to develop a fundamental understanding of their light absorption properties and energy transfer dynamics. In this work, we report distance-dependent energy transfer dynamics from a molecular photosensitizer (RuN3) to ZIF-67, where the distance between RuN3 and ZIF-67 is finely tuned by depositing an ultrathin Al 2 O 3 layer on the ZIF-67 surface using an atomic layer deposition (ALD) method. We show that energy transfer time decreases with increasing distance between RuN3 and ZIF-67 and the Förster radius is estimated to be 14.4 nm. 

Metal organic frameworks (MOFs) have emerged as a novel template to develop porous photocatalytic materials for solar fuel conversion. In this work, we report the synthesis, charge separation dynamics, and photocatalytic performance of the TiO 2 /CuO heterostructure derived from mixed-phase MOFs based on Ti and Cu metal nodes, which demonstrates significantly enhanced catalytic activity for the hydrogen evolution reaction (HER) compared to metal oxides derived from single node MOFs. More importantly, using transient absorption spectroscopy, we identified the specific role each component in the heterostructure plays and unravelled the key intermediate species that is responsible for the exceptional photocatalytic activity of the heterostructure. We found that the HER is initiated with ultrafast electron transfer (<150 fs) from the molecular photosensitizer to the conduction band of TiO 2 , where TiO 2 acts as an electron mediator and shuttles the electron to the CuO cocatalyst, facilitating charge separation and ultimately boosting the HER efficiency. These results not only demonstrate the great potential of using mixed-phase MOFs as templates to synthesize mesoporous heterostructure photocatalysts but also provide important insight into the HER mechanism. 

Metal organic frameworks (MOFs) have emerged as promising photocatalytic materials for solar energy conversion. However, a fundamental understanding of light harvesting and charge separation (CS) dynamics in MOFs remains underexplored, yet they are key factors that determine the efficiency of photocatalysis. Herein, we report the design and CS dynamics of the Ce–TCPP MOF using ultrafast spectroscopic methods. 

Zeolitic imidazolate frameworks (ZIFs) represent a novel class of porous crystalline materials that have demonstrated potential as light harvesting materials for solar energy conversion. In order to facilitate their application in solar energy conversion, it is necessary to expand their absorption further into the realm of the solar spectrum. In this work, we report the incorporation of semiconductor cadmium sulfide nanowires (CdS NWs) into ZIF-67 (CdS@ZIF-67), where a broader region of the solar spectrum can be absorbed by CdS NWs and relayed to ZIF-67 through an energy transfer (EnT) process. Using steady-state emission and time resolved emission and absorption spectroscopy, we show that efficient EnT can occur from CdS NWs to ZIF-67 by selective excitation of CdS NWs. The EnT time is ∼729.9 ps, which corresponds to 71.2% EnT efficiency.