Constructing photocatalyst systems to functionalize the inert C−H bonds has attracted extensive research interest. However, purposeful modulation of interfacial charge transfer in heterostructures remains a challenge, as it usually suffers from sluggish kinetics. Reported herein is an easy strategy to construct the heteroatom‐induced interface for developing the titanium‐organic frameworks (MOF‐902) @ thiophene‐based covalent triazine frameworks (CTF‐Th) nanosheets S‐scheme heterojunctions with controllable oxygen vacancies (OVs). Specifically, Ti atoms were first anchored onto the heteroatom site of CTF‐Th nanosheets, and then grown into MOF‐902 via an interfacial Ti−S linkage, generating OVs. Using in situ X‐ray photoelectron spectroscopy (XPS), extended X‐ray absorption fine structure (EXAFS) spectroscopy and density functional theory (DFT) calculations, the enhanced interfacial charge separation and transfer induced by moderate OVs in the pre‐designed S‐scheme nanosheets was validated. The heterostructures exhibited an improved efficiency in photocatalytic C3‐acylation of indoles under mild conditions with a yield 8.2 times larger than pristine CTF‐Th or MOF‐902 and enabled an extended scope of substrates (15 examples). This performance is superior to state‐of‐the‐art photocatalyst and can be retained, without significant loss, after 12 consecutive cycles.

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It is considered to be one of the most effective strategies to prepare functionalized polypropylene (PP) materials via the melt grafting of polar monomers onto PP chains. However, the grafting efficiency of functional monomers is generally low. To achieve a high grafting efficiency, we explored the effect of tea polyphenols (C), which are good free radical scavengers, on the melt grafting of glycidyl methacrylate (GMA) onto PP chains initiated by dicumyl peroxide (DCP). Specifically, 0.5~3 wt% of tea polyphenols (C) were introduced to the PP/DCP/GMA melt blending system. The morphology, melt flow rate (MFR), thermal and mechanical properties of tea polyphenols (C) incorporated PP/DCP/GMA blends were investigated systematically. The results showed that the proper amount of tea polyphenols (C) (0.5~2 wt%) promoted the grafting of GMA. Unexpectedly, the PP backbone suffered from more severe degradation with the addition of tea polyphenols (C). The phenomena were ascribed to the reaction between phenolic hydroxyl groups of tea polyphenols (C) and epoxy groups of grafted GMA, which was revealed by the FTIR results. In addition, according to DSC and the tensile test, the co-grafting of GMA and tea polyphenols (C) improved the crystallization ability, yield strength and Young’s modulus of the PP matrix.

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